21 Jul
2018
21 Jul
'18
8:14 a.m.
hi
yesterday I was shocked by a couple of videos on Youtube where guys
pointed out their negative experiences with CD ROM and DVD RAM as
media for their own backup.
They complained their data completely lost after 5 years of storage in
CD ROMs, pointing out that their CDs were perfectly conserved and kept
clean without scratches, but all the data is gone lost since the media
is unreadable.
This is what they said in the video.
I have a lot of backup here stored in CDs, and I have recently bought
an SCSI DVDRAM unit to create new backups in caddies DVD-RAMs (of
4.2Gbyte each)
what is your experience?
21 Jul
21 Jul
9:30 a.m.
On Sat, Jul 21, 2018 at 05:14:00PM +0200, Carlo Pisani via cctalk wrote:
[...]
They complained their data completely lost after 5
years of storage in CD
ROMs, pointing out that their CDs were perfectly conserved and kept clean
without scratches, but all the data is gone lost since the media is
unreadable.
The lack of scratches is a red herring. CDs and DVDs are expected to get
scratched in normal use, and contain multiple levels of error-correcting codes
to protect against it. Cleaning can scratch them, so don't bother until the
discs are so filthy that the drive can't read them any more. Scratches along
the track corrupt more bits than radial scratches, which is why you should
clean them hole-to-rim rather than in a circular motion.
(Ordinary) recordable discs contain light-sensitive dyes which are affected by
UV. Some dyes are better than others, and some dyes are even so crap that
they'll self-erase in time without UV. So if you buy really shonky cheap media
and/or store it somewhere that's not lightproof, it'll become unreadable in a
matter of *months*.
I have a lot of backup here stored in CDs, and I have
recently bought an SCSI
DVDRAM unit to create new backups in caddies DVD-RAMs (of 4.2Gbyte each)
what is your experience?
If it's a backup, long-term durability isn't too much of a concern since under
normal circumstances you will never perform a restore, and you should be
backing-up often enough that there will be multiple copies anyway.
If you are making an archive copy for long-term storage, buy two different
brands of good-quality media, burn a copy to each, *verify them*, and then
store them in multiple locations in a lightsafe container. Ideally, re-copy the
discs every five years or so to make sure.
Counterintuitively, DVD-R is more durable than the less-dense CD-R; I'm utterly
unimpressed with my BD-R experience, finding that some disks were unreadable
after mere days.
For my backups, I just use whatever external USB drive is the cheapest at the
time. I have too much data that chopping it into 4.7GB chunks and swapping
discs is just impractical.
9:58 a.m.
On 07/21/2018 08:14 AM, Carlo Pisani via cctalk wrote:
what is your experience?
Generally very good. But then, my valuable stuff on CD-R was done on
MAM-A (Mitsui) "gold" media. Some of it is 20+ years old. On the other
hand, no CD-RW disk that still have has survived.
My experience with DVD-R has been somewhat variable.
--Chuck
10:26 a.m.
The stability of the dyes is only part of the problem. Even mass-produced
read-only optical media (e.g., movie/video content DVDs) can become
unreadable over time because the reflective layer (typically aluminum)
under the data-encoded layer corrodes due to the chemistry of the dyes and
encasing plastic, and heat accelerates the process. The "gold" media may
have enough of a protective layer of that noble metal (it's obviously not
solid gold) that corrosion doesn't occur - only a few atoms' thickness is
required.
On Sat, Jul 21, 2018 at 10:58 AM, Chuck Guzis via cctalk <
cctalk at classiccmp.org> wrote:
On 07/21/2018 08:14 AM, Carlo Pisani via cctalk
wrote:
what is your experience?
Generally very good. But then, my valuable stuff on CD-R was done on
MAM-A (Mitsui) "gold" media. Some of it is 20+ years old. On the other
hand, no CD-RW disk that still have has survived.
My experience with DVD-R has been somewhat variable.
--Chuck
11:52 a.m.
On 7/21/18 10:26 AM, Jim Manley via cctalk wrote:
Even mass-produced
read-only optical media (e.g., movie/video content DVDs) can become
unreadable over time because the reflective layer (typically aluminum)
under the data-encoded layer corrodes due to the chemistry of the dyes and
encasing plastic, and heat accelerates the process.
The edge of the disk is SUPPOSED to be sealed. On cheap media, you see it
oozing, and the aluminum oxidizing from the edge inward. This was pointed
out to me already in the late 90's.
11:58 a.m.
On Sat, 21 Jul 2018, Al Kossow via cctalk wrote:
The edge of the disk is SUPPOSED to be sealed. On
cheap media, you see it
oozing, and the aluminum oxidizing from the edge inward. This was pointed
out to me already in the late 90's.
Fortunately, unlike most spinning rust disks, the default is to start at
the center and work out. Therefore, discs that are not full will last a
little longer.
12:25 p.m.
what about MO? (magneto-optic disks)
- WORM (write once, read many)
- WMRM (write many, read many)
and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
which of them lasts for the most?
MO units and disks are a bit costly
say >=50 euro for 4.5Gbyte R/W cartridge
and say >=500 euro for the driver unit (SCSI)
1:50 p.m.
On Sat, 21 Jul 2018, Carlo Pisani via cctalk wrote:
what about MO? (magneto-optic disks)
- WORM (write once, read many)
- WMRM (write many, read many)
and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
which of them lasts for the most?
MO units and disks are a bit costly
say >=50 euro for 4.5Gbyte R/W cartridge
and say >=500 euro for the driver unit (SCSI)
"M-Disc" has the longest longevity claims.
'course they're all extrapolation. In a thousand years, it will be
obvious that they are exaggerated.
22 Jul
22 Jul
6:33 a.m.
On Jul 21, 2018, at 3:25 PM, Carlo Pisani via cctalk
<cctalk at classiccmp.org> wrote:
...
and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
which of them lasts for the most?
I don't know specifically. I do know that plain old audio tapes may fail -- I have
perhaps 100 cassettes recorded in the 1970s. Most of them are fine, but essentially all
of them that are Fuji brand have failed utterly.
paul
8:52 a.m.
On 07/22/2018 06:33 AM, Paul Koning via cctalk wrote:
Half-inch open-reel tape at 1600 PE density. Should be good for 50
years at least.
--Chuck
On Jul 21, 2018, at 3:25 PM, Carlo Pisani via
cctalk <cctalk at classiccmp.org> wrote:
...
and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
which of them lasts for the most?
I don't know specifically. I do know that plain old audio tapes may fail -- I have
perhaps 100 cassettes recorded in the 1970s. Most of them are fine, but essentially all
of them that are Fuji brand have failed utterly. 
9:11 a.m.
On 07/22/2018 10:52 AM, Chuck Guzis via cctalk wrote:
On 07/22/2018 06:33 AM, Paul Koning via cctalk wrote:
Half-inch open-reel tape at 1600 PE density. Should be good for 50
years at least.
Well, you are one of the experts in this, but it all depends
on storage conditions. Also, the extended-length tapes were
too thin, and suffered from creasing and print-through.
Badly stored, and you can kiss your data goodbye in less
than 5 years.
Jon
On Jul 21, 2018, at 3:25 PM, Carlo Pisani via
cctalk <cctalk at classiccmp.org> wrote:
...
and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
which of them lasts for the most?
I don't know specifically. I do know that
plain old audio tapes may fail -- I have perhaps 100 cassettes recorded in the 1970s.
Most of them are fine, but essentially all of them that are Fuji brand have failed
utterly.
11:06 a.m.
thus DDS4, LTO2, DLT: which is the best tape?
2018-07-22 18:11 GMT+02:00 Jon Elson via cctalk <cctalk at classiccmp.org>:
On 07/22/2018 10:52 AM, Chuck Guzis via cctalk wrote:
On 07/22/2018 06:33 AM, Paul Koning via cctalk wrote:
Half-inch open-reel tape at 1600 PE density. Should be good for 50
years at least.
Well, you are one of the experts in this, but it all depends on storage
conditions. Also, the extended-length tapes were too thin, and suffered
from creasing and print-through. Badly stored, and you can kiss your data
goodbye in less than 5 years.
Jon On Jul 21, 2018, at 3:25 PM, Carlo Pisani via
cctalk
<cctalk at classiccmp.org> wrote:
...
and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
which of them lasts for the most?
I don't know specifically. I do know that plain old audio tapes may fail
-- I have perhaps 100 cassettes recorded in the 1970s. Most of them are
fine, but essentially all of them that are Fuji brand have failed utterly. 
1:06 p.m.
On Jul 22, 2018, at 11:06 AM, Carlo Pisani via cctalk
<cctalk at classiccmp.org> wrote:
thus DDS4, LTO2, DLT: which is the best tape?
I wouldn?t touch 4mm DAT tapes with a ten foot pole, if I can help it. I?ve used them in
the past, but only in special cases, OR more importantly when forced to.
You can?t buy new LTO2 or DLT drives (I think the last DLT drives were DLT8000?s). Even
Super-DLT tapes are obsolete.
At this point, for tape, I recommend LTO8, and if this is for Archival purposes, you?ll
need to refresh to LTO9 when released. LTO8 introduces an evil little gotcha. While
previous versions of the drives, have been able to read two versions back, LTO8 can?t.
I?ve failed to see any reason behind your questions. If you?re looking for a long-term
archival solution, look to cloud storage (either on-prem, or off-prem). Sure tape is
cheap, but when you start looking at other costs, such as storage and handling, it becomes
expensive.
This touches on one of my personal projects this year. I virtualized my backup
infrastructure for my OpenVMS systems, and then I went a step further, and have
virtualized most of my OpenVMS environment. I still need to virtualize my DECnet area
router. While all the data is moved, I?m still working to move some apps. It makes
protecting my data easy. My primary interest is the OS and software, while in the past
I?ve been focused on running on real hardware, virtualization is looking real nice, even
for working systems where I have plenty of spares.
Zane
6:08 p.m.
On Jul 22, 2018, at 4:06 PM, Zane Healy via cctalk
<cctalk at classiccmp.org> wrote:
Cloud storage as in "handled by some cloud company" is only as good as the
longevity of that company. If it shuts down suddenly because of poor management or fraud,
your data is almost certainly gone. Or it might end up disclosed to whoever pays pennies
on the dollar for the company assets.
On premises, sure, but now it's just a question of what medium you like. Those
storage devices probably use disks, or maybe flash storage. How long do those last? For
example, take a look at the "power off" retention time spec for flash storage,
it's surprisingly short. And how long is the relevant software available?
(That's a concern for any kind of digital storage, of course.)
paul
...
I?ve failed to see any reason behind your questions. If you?re looking for a long-term
archival solution, look to cloud storage (either on-prem, or off-prem). Sure tape is
cheap, but when you start looking at other costs, such as storage and handling, it becomes
expensive.
6:34 p.m.
On Jul 22, 2018, at 6:08 PM, Paul Koning
<paulkoning at comcast.net> wrote:
There are only a couple cloud companies I?d recommend storing data with, for precisely the
reasons you give. Storing with two would be advisable. Or a hybrid on and off premises
approach. For my photography archives, I?m taking a hybrid approach, recent changes are
backed up to Drobo, everything is cloned and kept offsite, and then all photo?s are also
sent to Cloud Storage. Once you start planning for Backups as part of your storage
purchases, it becomes easier to handle.
On premises has the exact same problem as tape. You must have a refresh plan. That?s the
advantage of off prem, you don?t have to worry about refresh.
For archives to be done right, you need at least two copies, excellent documentation, and
a solid refresh plan.
Zane
On Jul 22, 2018, at 4:06 PM, Zane Healy via
cctalk <cctalk at classiccmp.org> wrote:
Cloud storage as in "handled by some cloud company" is only as good as the
longevity of that company. If it shuts down suddenly because of poor management or fraud,
your data is almost certainly gone. Or it might end up disclosed to whoever pays pennies
on the dollar for the company assets.
On premises, sure, but now it's just a question of what medium you like. Those
storage devices probably use disks, or maybe flash storage. How long do those last? For
example, take a look at the "power off" retention time spec for flash storage,
it's surprisingly short. And how long is the relevant software available?
(That's a concern for any kind of digital storage, of course.) ...
I?ve failed to see any reason behind your questions. If you?re looking for a long-term
archival solution, look to cloud storage (either on-prem, or off-prem). Sure tape is
cheap, but when you start looking at other costs, such as storage and handling, it becomes
expensive.
6:47 p.m.
On 07/22/2018 06:34 PM, Zane Healy via cctalk wrote:
On premises has the exact same problem as tape. You
must have a refresh plan. That?s the advantage of off prem, you don?t have to worry about
refresh.
I don't exactly follow you. In the case of a specific example for NASA
and its vendors a given mission may involve tens of thousands of tapes.
When a mission concludes, tapes are usually bundled off to a warehouse
and then later junked. There's no money in the mission budget for
preservation ad perpetuum.
--Chuck
7:33 p.m.
On Jul 22, 2018, at 6:47 PM, Chuck Guzis via cctalk
<cctalk at classiccmp.org> wrote:
On 07/22/2018 06:34 PM, Zane Healy via cctalk wrote:
That?s the whole point of Cloud-based archives, as long as someone pays the ?small? annual
bill, the data is preserved, and someone else worries about the refresh of the data to
more modern storage solutions. Theoretically it?s also easier to find data in the cloud,
but that depends on if you simply throw the data up there in the cloud, or if you take the
time to do it right. My guess is most will simply toss it up into the cloud and forget
about it. At some point, some bean-counter will ask why the bill has grown so large, and
then?
Zane
On premises has the exact same problem as tape.
You must have a refresh plan. That?s the advantage of off prem, you don?t have to worry
about refresh.
I don't exactly follow you. In the case of a specific example for NASA
and its vendors a given mission may involve tens of thousands of tapes.
When a mission concludes, tapes are usually bundled off to a warehouse
and then later junked. There's no money in the mission budget for
preservation ad perpetuum.
--Chuck 
8:07 p.m.
Is there any relationship betwween the SPEED at which laser-disks are
written and the length of time that the recording will last?
Kurt
> On Jul 22, 2018, at 6:47 PM, Chuck Guzis via
cctalk
> <cctalk at classiccmp.org> wrote:
>
> On 07/22/2018 06:34 PM, Zane Healy via cctalk wrote:
>
>> On premises has the exact same problem as tape. You must have a
>> refresh plan. That???s the advantage of off prem, you don???t have to
>> worry about refresh.
>
> I don't exactly follow you. In the case of a specific example for NASA
> and its vendors a given mission may involve tens of thousands of tapes.
> When a mission concludes, tapes are usually bundled off to a warehouse
> and then later junked. There's no money in the mission budget for
> preservation ad perpetuum.
>
> --Chuck
9:05 p.m.
Throughout this whole thread, I've been tempted to say that you get better
data fidelity if you take a green magic marker and mark the edges of the
disk...
Of course, I know people here will get that old, tired meme... It got me
wondering, though, if anybody tested that hypothesis for longevity since
the marker would seal the edges... maybe :)
Warner
On Sun, Jul 22, 2018 at 9:07 PM, hollandia--- via cctalk <
cctalk at classiccmp.org> wrote:
Is there any relationship betwween the SPEED at which
laser-disks are
written and the length of time that the recording will last?
Kurt
> On Jul 22, 2018, at 6:47 PM, Chuck Guzis via
cctalk
> <cctalk at classiccmp.org> wrote:
>
> On 07/22/2018 06:34 PM, Zane Healy via cctalk wrote:
>
>> On premises has the exact same problem as tape. You must have a
>> refresh plan. That?s the advantage of off prem, you don?t have to
>> worry about refresh.
>
> I don't exactly follow you. In the case of a specific example for NASA
> and its vendors a given mission may involve tens of thousands of tapes.
> When a mission concludes, tapes are usually bundled off to a warehouse
> and then later junked. There's no money in the mission budget for
> preservation ad perpetuum.
>
> --Chuck
9:12 p.m.
On 07/22/2018 09:05 PM, Warner Losh via cctalk wrote:
Of course, I know people here will get that old, tired
meme... It got me
wondering, though, if anybody tested that hypothesis for longevity since
the marker would seal the edges... maybe :)
I don't know about sealing anything, as the layer of ink deposited would
likely be so thin and porous.
I'd almost forgotten about that old chestnut. Fortunately, Snopes
remembers:
https://www.snopes.com/fact-check/bewaring-of-the-green/
--Chuck
9:38 p.m.
On Sun, 22 Jul 2018, Chuck Guzis via cctalk wrote:
I'd almost forgotten about that old chestnut.
Fortunately, Snopes
remembers:
https://www.snopes.com/fact-check/bewaring-of-the-green/
But, what about using a gold USB cable?
Surely the quality of the power filtration must make a difference.
And, what about the SOURCE of the power? Wouldn't discs be more reliable
if the drive is driven by solar power, rather than nuclear?
Vibrations are an obvious culprit. That can be easily proven by
beating on drums on the table where the drive is. The burning should be
done in an acoustically sealed environment.
Light leakage mmust also affect it. All burning should be done in total
darkness, although some claim that a #10 safelight should be OK.
. . .
23 Jul
23 Jul
3:03 a.m.
Grumpy Ol' Fred wrote:
On Sun, 22 Jul 2018, Chuck Guzis via cctalk wrote:
Only if it is pure gold. None of this plated nonsense.
I'd almost forgotten about that old chestnut.
Fortunately, Snopes
remembers:
https://www.snopes.com/fact-check/bewaring-of-the-green/
But, what about using a gold USB cable?
Surely the quality of the power filtration must make a difference.
Well, if we are talking audio, maybe there would be a hum if it is not
filtered right.
However, my one time boss once told me that he had a friend who was an
audio nut who swore the sound from his amplifier was better when he
swapped the live and neutral wires in the mains plug...
And, what about the SOURCE of the power? Wouldn't discs be more reliable
if the drive is driven by solar power, rather than nuclear?
Surely rotating discs have to perform better when driven by power that comes
from a rotating machine, unless someone has been stupid
enough to have the
discs rotate in the opposite direction to the power generator...
Vibrations are an obvious culprit. That can be easily proven by
beating on drums on the table where the drive is. The burning should be
done in an acoustically sealed environment.
Or the drumming should be done in an oxygen free, airtight environment.
(There may be a brief period of instability at the beginning but things
should quickly settle down.)
Light leakage mmust also affect it. All burning should be done in total
darkness, although some claim that a #10 safelight should be OK.
If you can't see the disc turning, how can you know it has been burnt!
:-)
Regards,
Peter Coghlan.
10:48 a.m.
On 07/22/2018 09:05 PM, Warner Losh via cctalk wrote:
Throughout this whole thread, I've been tempted to
say that you get better
data fidelity if you take a green magic marker and mark the edges of the
disk...
I think that the use of tapes in the 23rd century justifies their
reputation for durability:
http://memory-alpha.wikia.com/wiki/Microtape
--Chuck
12:26 p.m.
On Mon, Jul 23, 2018 at 11:48 AM, Chuck Guzis via cctalk <
cctalk at classiccmp.org> wrote:
I think that the use of tapes in the 23rd century
justifies their
reputation for durability:
http://memory-alpha.wikia.com/wiki/Microtape
Very impressive, since Microtape was first sold in 1963, as an enhancement
over the previous LINCtape (ca. 1961).
10:54 a.m.
On 07/22/2018 09:05 PM, Warner Losh via cctalk wrote:
Throughout this whole thread, I've been tempted to
say that you get better
data fidelity if you take a green magic marker and mark the edges of the
disk...
On the other hand, information on MicroSD cards is likely to end up in
the sewer system, lost between floorboard cracks or vacuumed or swept
into the rubbish bin accidentally.
IMIHO, a grievous error by making things too physically small. The
standard SD card is easy enough to pick out in a deep-pile carpet. Not
so, the usual black-colored MicriSD. The dog might well eat it without
even being aware of having done it.
Are there such things as "microSD" to "standard SD" adapters that
allows
for insertion of standard SD into mcroSD slots?
--Chuck
11:03 a.m.
On Mon, Jul 23, 2018 at 12:54 PM, Chuck Guzis via cctalk <
cctalk at classiccmp.org> wrote:
IMIHO, a grievous error by making things too physically small. The
standard SD card is easy enough to pick out in a deep-pile carpet. Not
so, the usual black-colored MicriSD. The dog might well eat it without
even being aware of having done it.
Are there such things as "microSD" to "standard SD" adapters that
allows
for insertion of standard SD into mcroSD slots?
I agree. Most sold today come with a microSD to SD adapter.
25 Jul
25 Jul
2:56 p.m.
On Mon, Jul 23, 2018 at 10:54:26AM -0700, Chuck Guzis via cctalk wrote:
On 07/22/2018 09:05 PM, Warner Losh via cctalk wrote:
Of course there are. Since both SD cards and ?SD cards have identical
electrical and protocol interfaces, those adapters are just passive pieces
of plastic and wires. In fact, a lot of ?SD cards sold these days come
packaged with a ?SD to SD card adapter.
Kind regards,
Alex.
--
"Opportunity is missed by most people because it is dressed in overalls and
looks like work." -- Thomas A. Edison
Throughout this whole thread, I've been
tempted to say that you get better
data fidelity if you take a green magic marker and mark the edges of the
disk...
On the other hand, information on MicroSD cards is likely to end up in
the sewer system, lost between floorboard cracks or vacuumed or swept
into the rubbish bin accidentally.
IMIHO, a grievous error by making things too physically small. The
standard SD card is easy enough to pick out in a deep-pile carpet. Not
so, the usual black-colored MicriSD. The dog might well eat it without
even being aware of having done it.
Are there such things as "microSD" to "standard SD" adapters that
allows
for insertion of standard SD into mcroSD slots? 
3:12 p.m.
On Jul 25, 2018, at 4:56 PM, Alexander Schreiber via
cctalk <cctalk at classiccmp.org> wrote:
While it is true that the ?SD? cards I?ve bought recently have actually been ?SD cards
with an adaptor so they can also fit into SD slots, it didn?t sound like that was what
Chuck was asking.
I have not seen an adaptor which will plug into a ?SD slot and then allow me to plug my
(visible-size) SD card into the adaptor. I do totally agree that both the adaptor and the
medium would be big enough to see in that case and that would be a good thing! However I
have seen applications for a ?SD card that would not mechanically work with the adaptor in
question, due to packaging constraints, so I would not expect that adaptor (if it exists)
to be a common item.
- Mark
Are there such things as "microSD" to
"standard SD" adapters that allows
for insertion of standard SD into mcroSD slots?
Of course there are. Since both SD cards and ?SD cards have identical
electrical and protocol interfaces, those adapters are just passive pieces
of plastic and wires. In fact, a lot of ?SD cards sold these days come
packaged with a ?SD to SD card adapter.
3:43 p.m.
> Are there such things as "microSD" to
"standard SD" adapters that allows
> for insertion of standard SD into mcroSD slots?
On Wed, 25 Jul 2018, Alexander Schreiber via cctalk wrote:
Of course there are. Since both SD cards and ?SD cards
have identical
electrical and protocol interfaces, those adapters are just passive pieces
of plastic and wires. In fact, a lot of ?SD cards sold these days come
packaged with a ?SD to SD card adapter.
Yes, micro-SD often comes with an adapter to use micro-SD in an SD slot.
But are there adapters readily available to connect an SD card to a
device that has a micro-SD slot?
(">> for insertion of standard SD into mcroSD slots?")
The word "TO" is often confused when discussing adapters, and any
discussion should AVOID using the words "TO" or "FROM".
For example, If I want to use a Micro-4/3 lens on a Leica bellows, then
which way is "TO"? Are we adapting the M4/3 lens to Leica bellows, or
adapting the Leica bellows to M4/2? You and I might know what we mean,
but eBay searches, . . .
(A: adapter to use the Leica bellows on a Micro-4/3 camera is readily
available for a couple of dollars. But for the lens onto the bellows,
is NOT readily available, however, there are extremely cheap sets of M4/3
extension tubes, with 52mm or 57mm x 0.75mm threads between the sections.
adapters between 39mmx24tpi and 52mm x 0.75mm are easier to come by.)
3:50 p.m.
At 05:43 PM 7/25/2018, Fred Cisin via cctalk wrote:
Yes, micro-SD often comes with an adapter to use
micro-SD in an SD slot.
But are there adapters readily available to connect an SD card to a device that has a
micro-SD slot?
(">> for insertion of standard SD into mcroSD slots?")
Wouldn't such a big-to-small adapter almost always be confounded
by form factors and clearances?
For many devices, the micro SD disappears into the device.
I'll be darned, they exist:
https://www.saikosystems.com/web/p-44-sd-to-microsd-converter.aspx?affiliat…
https://www.ebay.com/itm/Micro-SD-TO-SD-Card-Extension-Cable-Adapter-Extend…
https://www.aliexpress.com/item/TF-MicroSD-Male-To-SD-Female-SDHC-SDXC-Card…
- John
4:06 p.m.
> Yes, micro-SD often comes with an adapter to use
micro-SD in an SD slot.
> But are there adapters readily available to connect an SD card to a device that has a
micro-SD slot?
> (">> for insertion of standard SD into mcroSD slots?")
On Wed, 25 Jul 2018, John Foust via cctalk wrote:
Wouldn't such a big-to-small adapter almost always
be confounded
by form factors and clearances?
For many devices, the micro SD disappears into the device.
I'll be darned, they exist:
https://www.saikosystems.com/web/p-44-sd-to-microsd-converter.aspx?affiliat…
https://www.ebay.com/itm/Micro-SD-TO-SD-Card-Extension-Cable-Adapter-Extend…
https://www.aliexpress.com/item/TF-MicroSD-Male-To-SD-Female-SDHC-SDXC-Card…
and, in line with the treachery of descriptions of adapters, several of
those are micro-SD to micro-SD extenders, NOT size adapters!
But, one of those has "other alternatives" that seem to be the right one.
4:33 p.m.
On 07/25/2018 04:06 PM, Fred Cisin via cctalk wrote:
and, in line with the treachery of descriptions of adapters, several of
those are micro-SD to micro-SD extenders, NOT size adapters!
But, one of those has "other alternatives" that seem to be the right one.
The ones with a ribbon cable might actually be best for my
application--I'd like to mount a PCB with a uSD slot inside a larger box.
Thanks for the tip--I'll so some investigation.
--Chuck
5:56 p.m.
On Jul 25, 2018, at 3:43 PM, Fred Cisin via cctalk
<cctalk at classiccmp.org> wrote:
For example, If I want to use a Micro-4/3 lens on a Leica bellows, then which way is
"TO"? Are we adapting the M4/3 lens to Leica bellows, or adapting the Leica
bellows to M4/2? You and I might know what we mean, but eBay searches, . . .
(A: adapter to use the Leica bellows on a Micro-4/3 camera is readily available for a
couple of dollars. But for the lens onto the bellows,
is NOT readily available, however, there are extremely cheap sets of M4/3 extension
tubes, with 52mm or 57mm x 0.75mm threads between the sections. adapters between
39mmx24tpi and 52mm x 0.75mm are easier to come by.)
Why would I want to use a Micro-4/3 lens on my Leica?s, will it even cover the 35mm frame
(or full frame sensor)?
Zane
6:39 p.m.
> For example, If I want to use a Micro-4/3 lens on
a Leica bellows, then
On Wed, 25 Jul 2018, Zane Healy wrote:
Why would I want to use a Micro-4/3 lens on my
Leica?s, will it even
cover the 35mm frame (or full frame sensor)?
I wouldn't. But, I'd like to use the leica BELLOWS on the digital camera.
with some minor mods to the adapters, I might even be able to use the
auto-focus (for fine adjust, after course setting with the bellows).
I do, however, occasionally use Leica lenses on M4/3 and Sony-E. THOSE
adapters are very readily available and cheap.
7:53 p.m.
On 2018-07-25 10:39 PM, Fred Cisin via cctalk wrote:
I use Olympus bellows from the OM series with my M4/3 camera they are
much easier to adapt.? With the combination of bellows and microscope
objectives for lens I have been able to obtain very high magnification.
Paul.
> For
example, If I want to use a Micro-4/3 lens on a Leica bellows, then
On Wed, 25 Jul 2018, Zane Healy wrote:
Why would I want to use a Micro-4/3 lens on my
Leica?s, will it even
cover the 35mm frame (or full frame sensor)?
I wouldn't.? But, I'd like to use the leica BELLOWS on the digital
camera. with some minor mods to the adapters, I might even be able to
use the auto-focus (for fine adjust, after course setting with the
bellows).
I do, however, occasionally use Leica lenses on M4/3 and Sony-E. THOSE
adapters are very readily available and cheap.
4:28 p.m.
On 07/25/2018 02:56 PM, Alexander Schreiber wrote:
Of course there are. Since both SD cards and ?SD cards
have identical
electrical and protocol interfaces, those adapters are just passive pieces
of plastic and wires. In fact, a lot of ?SD cards sold these days come
packaged with a ?SD to SD card adapter.
Again, I've been misunderstood. I'm looking for an adapter that allows
one to use standard size SD cards in a MicroSD slot.
I can find only one incarnation of this idea in a rather shoddy-locking
hunk of F44 PCB with a uSD socket mounted on it.
If someone knows of a slicker, better-designed adapter, I'd like to see it.
--Chuck
4:37 p.m.
On Wed, 25 Jul 2018, Chuck Guzis via cctalk wrote:
Again, I've been misunderstood. I'm looking
for an adapter that allows
one to use standard size SD cards in a MicroSD slot.
I can find only one incarnation of this idea in a rather shoddy-locking
hunk of F44 PCB with a uSD socket mounted on it.
If someone knows of a slicker, better-designed adapter, I'd like to see it.
Like this? :
https://www.ebay.com/itm/183299125079
5:14 p.m.
On 07/25/2018 04:37 PM, Fred Cisin via cctalk wrote:
Like this? :
https://www.ebay.com/itm/183299125079
That might have possibilities. I've ordered a couple of eBay item
362055535419, for 2 clams and change each. Same thing from Cathay.
Thanks,
Chuck
27 Jul
27 Jul
3:09 a.m.
On Wed, Jul 25, 2018 at 04:28:54PM -0700, Chuck Guzis wrote:
On 07/25/2018 02:56 PM, Alexander Schreiber wrote:
Ah, sorry.
Of course there are. Since both SD cards and ?SD
cards have identical
electrical and protocol interfaces, those adapters are just passive pieces
of plastic and wires. In fact, a lot of ?SD cards sold these days come
packaged with a ?SD to SD card adapter.
Again, I've been misunderstood. I'm looking for an adapter that allows
one to use standard size SD cards in a MicroSD slot. I can find only one incarnation of this idea in a
rather shoddy-locking
hunk of F44 PCB with a uSD socket mounted on it.
If someone knows of a slicker, better-designed adapter, I'd like to see it.
I'm not very optimistic here, given that the ?SD card end of such an
adapter is going to be quite mechanically weak due to size and thickness
constraints. It would just be something that waits for a gentle accidental
push to break it to pieces.
Kind regards,
Alex.
--
"Opportunity is missed by most people because it is dressed in overalls and
looks like work." -- Thomas A. Edison
11:15 a.m.
> Again, I've been misunderstood. I'm
looking for an adapter that allows
> one to use standard size SD cards in a MicroSD slot.
On Fri, 27 Jul 2018, Alexander Schreiber via cctalk wrote:
I'm not very optimistic here, given that the ?SD
card end of such an
adapter is going to be quite mechanically weak due to size and thickness
constraints. It would just be something that waits for a gentle accidental
push to break it to pieces.
Probably.
but, ideally, the male end would be the size of a micro-sd, with a cable
from it, to avoid that, and to make placement of the
female (SD) end more
convenient.
24 Jul
24 Jul
10:55 a.m.
On 7/22/18 2:06 PM, Zane Healy via cctalk wrote:
I wouldn?t touch 4mm DAT tapes with a ten foot pole,
if I can help
it. I?ve used them in the past, but only in special cases, OR more
importantly when forced to.
I had reasonable success with DDS2 & DDS3 DATs back in the day. I
routinely wrote to and read from the tapes over about 18 months. Though
I have no idea how well they would last longer term than that.
QIC-80 drives were really before me, but I did manage to pick some up
from garage sales and read their contents 5+ years
after they were
written. I usually had to retention the tapes one (or more)
time(s) to
be able to get a (few) good reads off of them. I do think they earned
their reputation that I've heard others talk about.
That being said, CuriousMark is having decent luck with QIC cartridges
in his old HP equipment.
You can?t buy new LTO2 or DLT drives (I think the last
DLT drives
were DLT8000?s). Even Super-DLT tapes are obsolete.
I've got no personal experience with DLT. I have multiple colleagues
that used them to backup multiple servers (before I entered the scene).
At this point, for tape, I recommend LTO8, and if this
is for
Archival purposes, you?ll need to refresh to LTO9 when released.
LTO8 introduces an evil little gotcha. While previous versions of
the drives, have been able to read two versions back, LTO8 can?t.
All of my professional experience with tape has been decidedly
non-archival. It was always used for nightly / weekly / monthly backups
and consumed within 18 months.
I?ve failed to see any reason behind your questions.
If you?re
looking for a long-term archival solution, look to cloud storage
(either on-prem, or off-prem). Sure tape is cheap, but when you
start looking at other costs, such as storage and handling, it
becomes expensive.
I think you need to be EXTREMELY careful when selecting cloud storage
vendors. I've heard about a fewer smaller ones folding up shop. I want
to say I've heard of at least one going away fast enough that people had
problems getting their data back. So, make sure you pick one that is
reputable and / or guarantees time to retrieve data that you have stored
with them.
This touches on one of my personal projects this year.
I virtualized
my backup infrastructure for my OpenVMS systems, and then I went a
step further, and have virtualized most of my OpenVMS environment. I
still need to virtualize my DECnet area router. While all the data
is moved, I?m still working to move some apps. It makes protecting
my data easy. My primary interest is the OS and software, while in
the past I?ve been focused on running on real hardware,
virtualization is looking real nice, even for working systems where I
have plenty of spares.
I would love to know more about how you did this. Do you have any blog
articles or the likes that I can read to learn?
--
Grant. . . .
unix || die
23 Jul
23 Jul
8:51 a.m.
On Sun, Jul 22, 2018 at 08:06:24PM +0200, Carlo Pisani via cctalk wrote:
thus DDS4, LTO2, DLT: which is the best tape?
If you even remotely care about your data, stay far away from DDS.
In a previous job we used DDS3 tapes as system backup and restore
tapes (since the machines could boot from them). Those were written
at most once a month and in 1.5 years there I accumulated a nice stack
of 'dead' (hard read errors) tapes. I think none survived more than
half a dozen write cycles and they got read not much more.
Generally, avoiding any helical scan tape technology (DDS, AIT) is
probably a good idea on account of increased head & tape wear this
causes.
Personally, I have good experience with both DLT and LTO, both are
linear scan technologies and IIRC are specified to last at least
1-2 decades given proper storage.
Of course, you still want several generations and copies of your backups.
Another thing to keep in mind: it is nice if your backup medium lasts
decades, but what about the reader for it? Will that be available
down the road as well and usable?
And, not to forget: what format are your backups written in. Something
standard like POSIX tar or some proprietary format used by some
commercial software, which might have availability issues in the
future.
Kind regards,
Alex.
2018-07-22 18:11 GMT+02:00 Jon Elson via cctalk <cctalk at classiccmp.org>:
> On 07/22/2018 10:52 AM, Chuck Guzis via cctalk wrote:
>>
>> On 07/22/2018 06:33 AM, Paul Koning via cctalk wrote:
>>>
>>>
>>>> On Jul 21, 2018, at 3:25 PM, Carlo Pisani via cctalk
>>>> <cctalk at classiccmp.org> wrote:
>>>>
>>>> ...
>>>> and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
>>>>
>>>> which of them lasts for the most?
>>>
>>> I don't know specifically. I do know that plain old audio tapes may
fail
>>> -- I have perhaps 100 cassettes recorded in the 1970s. Most of them are
>>> fine, but essentially all of them that are Fuji brand have failed utterly.
>>
>> Half-inch open-reel tape at 1600 PE density. Should be good for 50
>> years at least.
>>
>>
> Well, you are one of the experts in this, but it all depends on storage
> conditions. Also, the extended-length tapes were too thin, and suffered
> from creasing and print-through. Badly stored, and you can kiss your data
> goodbye in less than 5 years.
>
> Jon
--
"Opportunity is missed by most people because it is dressed in overalls and
looks like work." -- Thomas A. Edison
10:19 a.m.
New subject: how good is the data reliability with BD-R (Blu-Ray)
My BD-R story:
For a little bit I was trying to go Blue Ray for backup of conference
talks I was recording at the time. I picked up a Samsung BD-R drive and
some memorex media. The media for BD-R comes in a High to low and low to
high versions. One is dye based not for long term, the other type is long
term. The Memorex type I got was the long term type.
I carefully made 2 or 3 copies of each set of video files. Each event took
2 to 3 discs (Was recording events live using Blackmagic ATEM system, 5GB
per hour is the data rate in 1080i60 h264 encoded.)
After about 9 months I went to copy some data back. It was all gone.
Everything deteriorated and all the data was unreadable. Before I bought
the drive I looked for info on reliability and didn't find any indicators
that the media sometimes has severe issues.
Since then I kind of swore off optical media. I have some Verbatim discs
but I haven't used them yet. I figure they will do better, but still
bitter over losing the information from the earier events.
I have around 60TB of spinning disks at home, but will be going tape in
the future.
A lot of my data is conference video and backups of laser show tapes which
often are 8 channels of WAV data @ 48khz, so ~3-4GB per 30 minute show
tape.
24 Jul
24 Jul
10:55 a.m.
On 7/23/18 9:51 AM, Alexander Schreiber via cctalk wrote:
Another thing to keep in mind: it is nice if your
backup medium lasts
decades, but what about the reader for it? Will that be available
down the road as well and usable?
I seem to recall reading about a ""tape drive that wrote optically to
the medium in such a way that it could be read optically without overly
complex magnification. I want to say something between a good
magnifying glass and a cheap microscope allowed people with nominally
20/20 vision to be able to read the bits on the tape.
The tape also purportedly had a leader that was direction on how to read
the tape manually (optically).
The idea was that it was possible (all be it tedious) for a human to
read the tape and gain access to the contents there in.
And, not to forget: what format are your backups
written in. Something
standard like POSIX tar or some proprietary format used by some
commercial software, which might have availability issues in the
future.
Yep.
I've read a few discussions where some of the oldest and biggest formats
that take up the most space are the most likely to be recovered. ASCII
text being one of the most likely.
If you do use a less open / more proprietary format make sure to be
mindful of what sort of blocking / chunking that it does. The idea
being that you don't want corruption somewhere in the tape to render the
rest of the tape inaccessible.
This also nods towards redundancy. Having multiple copies of the same
data different places on the tape and / or on multiple tapes makes it
much more likely that if (read: when) corruption occurs, you don't
actually have data loss because ideally redundant copies are good. Or
at least between all of the copies you have at least one good aggregate
copy of the data.
--
Grant. . . .
unix || die
22 Jul
22 Jul
5:13 p.m.
Below is a sampling of disks recorded between 2001 and 2009. It is
likely that the disks of the same type were from the same package
because I don't use many disks. They were stored without much care,
but in a spaces tolerable to humans for reasonable periods.
Imation CD-R recorded 2003/12/29 readable
Imation CD-R recorded 2004/01/02 recoverable errors
Imation CR-R recorded 2001/12/18 recoverable errors
Imation CD-R recorded 2005/07/15 recoverable errors
Imation CD-R recorded 2001/12/24 recoverable errors
TDK DVD-R recorded 2006/02/05 recoverable errors
TDK DVD-R recorded 2009/09 unrecoverable errors. The
edges of the disk have a strange faded coloration.
TDK DVD-R recorded 2007/10/07 readable
Memorex CD-R recorded 2005 unrecoverable errors
-chuck
5:46 p.m.
Somewhat of a tangent, but this just popped up for me.
https://www.theatlantic.com/technology/archive/2018/07/microfilm-lasts-half…
and I thought of this thread. Apologies if it's a duplicate..
Warner
On Sun, Jul 22, 2018 at 6:13 PM, Charles Dickman via cctalk <
cctalk at classiccmp.org> wrote:
Below is a sampling of disks recorded between 2001 and
2009. It is
likely that the disks of the same type were from the same package
because I don't use many disks. They were stored without much care,
but in a spaces tolerable to humans for reasonable periods.
Imation CD-R recorded 2003/12/29 readable
Imation CD-R recorded 2004/01/02 recoverable errors
Imation CR-R recorded 2001/12/18 recoverable errors
Imation CD-R recorded 2005/07/15 recoverable errors
Imation CD-R recorded 2001/12/24 recoverable errors
TDK DVD-R recorded 2006/02/05 recoverable errors
TDK DVD-R recorded 2009/09 unrecoverable errors. The
edges of the disk have a strange faded coloration.
TDK DVD-R recorded 2007/10/07 readable
Memorex CD-R recorded 2005 unrecoverable errors
-chuck
6:02 p.m.
On Jul 22, 2018, at 8:46 PM, Warner Losh via cctalk
<cctalk at classiccmp.org> wrote:
Somewhat of a tangent, but this just popped up for me.
https://www.theatlantic.com/technology/archive/2018/07/microfilm-lasts-half…
and I thought of this thread. Apologies if it's a duplicate..
Warner
Interesting. The article seems to say that it isn't the images on the film that last
500 years, only the substrate. The images would last too, if done by silver nitrate
(original black & white technology). Later dye based stuff, like the blue you see on
DEC microfiche, not so clear. Probably not; I wouldn't trust organic dyes to last a
century.
I suppose that this stuff would be discussed on the Long Now Foundation website.
paul
6:06 p.m.
On Sun, 22 Jul 2018, Warner Losh via cctalk wrote:
Somewhat of a tangent, but this just popped up for
me.
https://www.theatlantic.com/technology/archive/2018/07/microfilm-lasts-half…
and I thought of this thread. Apologies if it's a duplicate..
Iff deliberately processed for archival permanence, metallic silver is
long lasting.
But, there have always been a lot of shortcuts taken to save time or
money.
A LOT of photographic materials were not adequately fixed ("hypo"/Sodium
Thiosulfate?), and/or not adequately washed and or neutralizing the fixer.
Archivala permanence calls for a fixer neutralizer, not just washing.
For example, the Polaroid 55-P/N (4x5 print plus negative) had a different
exposure index for the negative and the print, so one or the other would
be off on exposure. The negative desperately needed to be more
thoroughly fixed and washed, or it didn't last at all.
Similarly with "stabilization" black and white prints. (anybody want an
extra large stabilization processor? home lab movie film processing
equipment?)
There were many variations in the paper itself for photo prints. Some
lasted better than others. Kodak has discontinued manufacturing of B&W
photo paper, but there are a few other manufacturers still around.
Color was done with dies, rather than metallic silver, and those fade.
Remember how OVERLY bright Kodachrome was? Ektachrome held up a bit
better.
Longevity of digital data is predicated on periodic re-copying, and
periodic transfer to other and newer media.
"Cloud" is tempting, but the internet is written in sand; do you know ehre
your data is?
--
Grumpy Ol' Fred cisin at xenosoft.com
6:11 p.m.
On 07/22/2018 05:46 PM, Warner Losh via cctalk wrote:
Somewhat of a tangent, but this just popped up for
me.
https://www.theatlantic.com/technology/archive/2018/07/microfilm-lasts-half…
I read through to the end of the article and can't quite see where the
500 year lifetime comes in. Microfilm is a Mylar base with a gelatin
coating containing bits of elemental silver, no? Why would this last
for 500 years? Do we even have a 250-year old piece of intact gelatin?
--Chuck
23 Jul
23 Jul
11 a.m.
On Sun, Jul 22, 2018 at 7:13 PM, Charles Dickman via cctalk <
cctalk at classiccmp.org> wrote:
Below is a sampling of disks recorded between 2001 and
2009. It is
likely that the disks of the same type were from the same package
because I don't use many disks. They were stored without much care,
but in a spaces tolerable to humans for reasonable periods.
Imation CD-R recorded 2003/12/29 readable
Imation CD-R recorded 2004/01/02 recoverable errors
Imation CR-R recorded 2001/12/18 recoverable errors
Imation CD-R recorded 2005/07/15 recoverable errors
Imation CD-R recorded 2001/12/24 recoverable errors
TDK DVD-R recorded 2006/02/05 recoverable errors
TDK DVD-R recorded 2009/09 unrecoverable errors. The
edges of the disk have a strange faded coloration.
TDK DVD-R recorded 2007/10/07 readable
Memorex CD-R recorded 2005 unrecoverable errors
Probably a good idea to use something like RAR with parity. I know I have
downloaded some multi-segment binaries in RAR format from usenet with
several missing segments and as long as I had the parity file set it could
successfully recover the entire archive.
2:11 p.m.
Probably a good idea to use something like RAR with
parity. I know I
have
downloaded some multi-segment binaries in RAR format from usenet with
several missing segments and as long as I had the parity file set it
could
successfully recover the entire archive.
Parity will only take you so far. It is the same as RAID - you can only tolerate so many
disk failures before the whole thing collapses like a house of cards. It works well w/
UseNet because usually the errors are small compared to the data set. However, if you were
missing say three RAR files out of six then one PAR file is not going to save you.
-Ali
24 Jul
24 Jul
3:25 a.m.
has anyone ever used Iomega Rev as backup media?
how good is that?
2018-07-23 23:11 GMT+02:00 Ali via cctalk <cctalk at classiccmp.org>:
Probably a
good idea to use something like RAR with parity. I know I
have
downloaded some multi-segment binaries in RAR format from usenet with
several missing segments and as long as I had the parity file set it
could
successfully recover the entire archive.
Parity will only take you so far. It is the same as RAID - you can only tolerate so many
disk failures before the whole thing collapses like a house of cards. It works well w/
UseNet because usually the errors are small compared to the data set. However, if you were
missing say three RAR files out of six then one PAR file is not going to save you.
-Ali
10:55 a.m.
On 7/23/18 12:00 PM, Geoffrey Oltmans via cctalk wrote:
Probably a good idea to use something like RAR with
parity. I know I
have downloaded some multi-segment binaries in RAR format from usenet
with several missing segments and as long as I had the parity file
set it could successfully recover the entire archive.
I too have had good luck with
RAR files and their (optional) accompany
PAR files. The key word being "optional" as in not there by default.
I think some other archive formats also have (optional) built in redundancy.
I've also heard some noise that some archive file formats are
particularly susceptible to corruption and can't be recovered. So I do
think it's very important to carefully pick the archive format and options.
--
Grant. . . .
unix || die
21 Jul
21 Jul
11:55 a.m.
Longevity has always been an issue.
(and we already know that 8" floppies outlast 3.5")
Does anybody here have experience with "M-Disc"?
It is available up to 100GB BDXL!
Drives start at less than $100; media is prices vary - the 100GB starts at
about $20 each, but the low capacity versions are bordering on
competitive.
The longevity claims are all extrapolations - turns out that nobody has
ever ACTUALLY stored one for more than 30 years. If/when I can get a
ride, I'd be glad to take one back to the sixties, to get a half-century
test.
--
Grumpy Ol' Fred cisin at xenosoft.com
23 Jul
23 Jul
11:55 a.m.
Does anybody here have experience with
"M-Disc"?
It is available up to 100GB BDXL!
Drives start at less than $100; media is prices vary - the 100GB starts
at
about $20 each, but the low capacity versions are bordering on
competitive.
Fred,
I have used M-Disc to archive photos and digital media. So far so good.
Problem is you need an M-Disc drive to read it for sure - what does that
mean? Well the disc is supposed to be compatible across all DVD readers BUT
I have found my older Lite-On IDE drives, which were considered very good
back in the day, have had problems reading the DVDs. So your mileage may
vary...
Also of note the original company has gone bankrupt and their assets bought
out. The new owners are continuing to produce M-Disc media.
-Ali
12:57 p.m.
What kind of media is it DVD+R or DVD-R? I think DVD-R (Pioneer) came first
and all the original DVD burners support it and it is the most reliable if
you are making movies for older DVD players. DVD+R is a Sony and Phillips
design and the recording format is different.
The last generation of DVD recorders is +/- but anything IDE would probably
be DVD-R only and might have issues reading + disks.
-----Original Message-----
From: Ali via cctalk
Sent: Monday, July 23, 2018 2:55 PM
To: 'Fred Cisin' ; 'General Discussion: On-Topic and Off-Topic Posts'
Subject: RE: how good is the data reliability with CD ROM and DVD RAM?
Does anybody here have experience with
"M-Disc"?
It is available up to 100GB BDXL!
Drives start at less than $100; media is prices vary - the 100GB starts
at
about $20 each, but the low capacity versions are bordering on
competitive.
Fred,
I have used M-Disc to archive photos and digital media. So far so good.
Problem is you need an M-Disc drive to read it for sure - what does that
mean? Well the disc is supposed to be compatible across all DVD readers BUT
I have found my older Lite-On IDE drives, which were considered very good
back in the day, have had problems reading the DVDs. So your mileage may
vary...
Also of note the original company has gone bankrupt and their assets bought
out. The new owners are continuing to produce M-Disc media.
-Ali
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
1:20 p.m.
what about DVD-RAM?
are they good about data-reliability?
cost:
- SCSI DVD-RAM reader/writer, say about 180-240 euro, brand new
- DVD-RAM cartridge (disk + caddy), say about 20 euro per 5 disks, brand new
how long does a DVD-RAM last?
4.5Gbyte per disk is ok for me, I need to archive my source code
2018-07-23 21:57 GMT+02:00 TeoZ via cctalk <cctalk at classiccmp.org>:
What kind of media is it DVD+R or DVD-R? I think
DVD-R (Pioneer) came first
and all the original DVD burners support it and it is the most reliable if
you are making movies for older DVD players. DVD+R is a Sony and Phillips
design and the recording format is different.
The last generation of DVD recorders is +/- but anything IDE would probably
be DVD-R only and might have issues reading + disks.
-----Original Message----- From: Ali via cctalk
Sent: Monday, July 23, 2018 2:55 PM
To: 'Fred Cisin' ; 'General Discussion: On-Topic and Off-Topic Posts'
Subject: RE: how good is the data reliability with CD ROM and DVD RAM?
Does anybody here have experience with
"M-Disc"?
It is available up to 100GB BDXL!
Drives start at less than $100; media is prices vary - the 100GB starts
at
about $20 each, but the low capacity versions are bordering on
competitive.
Fred,
I have used M-Disc to archive photos and digital media. So far so good.
Problem is you need an M-Disc drive to read it for sure - what does that
mean? Well the disc is supposed to be compatible across all DVD readers BUT
I have found my older Lite-On IDE drives, which were considered very good
back in the day, have had problems reading the DVDs. So your mileage may
vary...
Also of note the original company has gone bankrupt and their assets bought
out. The new owners are continuing to produce M-Disc media.
-Ali
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
1:38 p.m.
On Jul 23, 2018, at 1:20 PM, Carlo Pisani via cctalk
<cctalk at classiccmp.org> wrote:
what about DVD-RAM?
are they good about data-reliability?
cost:
- SCSI DVD-RAM reader/writer, say about 180-240 euro, brand new
- DVD-RAM cartridge (disk + caddy), say about 20 euro per 5 disks, brand new
how long does a DVD-RAM last?
4.5Gbyte per disk is ok for me, I need to archive my source code
I realize this is the CLASSICCMP mail list, however, when talking about archiving data
today, why would you use classic tech, rather than modern tech?
If you?re looking at a SCSI DVD-RAM drive, I don?t care that it?s ?new?, I start to
wonder, just how *OLD* it is. Sure it might be ?New Old Stock (NOS)", but it might
also be ?Dead on Arrival (DOA)?.
If you are trying to archive data on ?Classic? hardware, if it has SCSI, then it surely
has network, and the ability to move your data to modern hardware.
Zane
2:07 p.m.
> Does anybody here have experience with
"M-Disc"?
> It is available up to 100GB BDXL!
> Drives start at less than $100; media is prices vary - the 100GB starts
> at about $20 each, but the low capacity versions are bordering on
> competitive.
On Mon, 23 Jul 2018, Ali wrote:
I have used M-Disc to archive photos and digital
media. So far so good.
Problem is you need an M-Disc drive to read it for sure - what does that
mean? Well the disc is supposed to be compatible across all DVD readers BUT
I have found my older Lite-On IDE drives, which were considered very good
back in the day, have had problems reading the DVDs. So your mileage may
vary...
Thank you.
OK, that is alarming. The claim that the discs produced are fully
compatible is bogus. That was an essential requirement. Next aspect
would be whether they are completely incompatible with EVERYTHING other
than M-Disc, or just SOME types of drives, and if so, WHICH ones.
From what I've read, the difference in drive
between BDXL and BDXL M-Disc
is trivial enough that there is no reason that ALL
BDXL wouldn't go that
way, unless there are patent issues.
Also of note the original company has gone bankrupt
and their assets bought
out. The new owners are continuing to produce M-Disc media.
The drives are being made by LG, Pioneer, etc., so that part is OK.
The media is being manufactured by Verbatim, Memorex, ?
Does the demise of the original company, and hence the licenses, place the
ability of Verbatim, Memorex, etc. to make the media at risk?
(or only the legal rights to use the logo?)
Is the new owner more stable, and/or did Verbatim, Memorex, et al, at
least negotiate contract provisions for continuation of license after
demise of licensors?
Is anybody else doing any significant work towards long-life media?
We need ongoing supply, continuation of compatable hardware, and adequate
(non-"trade-secret") documentation - without Belafon, we've lost the
knowledge, and have to speculate, exactly what his hardware does.
--
Grumpy Ol' Fred cisin at xenosoft.com
2:12 p.m.
I had a home CDR back when they were over $1000+ new. The media turned out
to be very reliable (and I have a bunch with gold, blue, green dye) and it
still readable as long as you didn't scratch the optical reflective layer. I
also used a laser printed paper cover which probably kept air out. I think
the media had better quality control when a single CDR was $8 a pop then
with a spool that costs $20. DVD recordable media was error prone if you
used DL disks. I only used CDRW media for short term moving of files so I
don't know how well they do long term. I have a BDXL Blueray drive I barely
use since anything I need to get at is either online on my server of offline
on a tape of some kind (LTO mostly but some DAT and AIT as well).
I have old IBM MO Worm disks that are still readable, same with all my MO
disks (3.5" 130MB, 5.25" 1.3GB) but drives can be iffy. I would bet that MO
media will outlast us all while finding a drive to read them will be a
problem.
-----Original Message-----
From: Carlo Pisani via cctalk
Sent: Saturday, July 21, 2018 11:14 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: how good is the data reliability with CD ROM and DVD RAM?
hi
yesterday I was shocked by a couple of videos on Youtube where guys
pointed out their negative experiences with CD ROM and DVD RAM as
media for their own backup.
They complained their data completely lost after 5 years of storage in
CD ROMs, pointing out that their CDs were perfectly conserved and kept
clean without scratches, but all the data is gone lost since the media
is unreadable.
This is what they said in the video.
I have a lot of backup here stored in CDs, and I have recently bought
an SCSI DVDRAM unit to create new backups in caddies DVD-RAMs (of
4.2Gbyte each)
what is your experience?
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
2:34 p.m.
On 07/21/2018 02:12 PM, TeoZ via cctalk wrote:
I have old IBM MO Worm disks that are still readable,
same with all my
MO disks (3.5" 130MB, 5.25" 1.3GB) but drives can be iffy. I would bet
that MO media will outlast us all while finding a drive to read them
will be a problem.
I've got a few old PMC Apex 4GB disks. I suspect that finding a working
drive will be most difficult. Heaven knows, mine died years ago.
--Chuck
2:43 p.m.
thus, MO drive units are not reliable?
2018-07-21 23:34 GMT+02:00 Chuck Guzis via cctalk <cctalk at classiccmp.org>:
On 07/21/2018 02:12 PM, TeoZ via cctalk wrote:
I have old IBM MO Worm disks that are still
readable, same with all my
MO disks (3.5" 130MB, 5.25" 1.3GB) but drives can be iffy. I would bet
that MO media will outlast us all while finding a drive to read them
will be a problem.
I've got a few old PMC Apex 4GB disks. I suspect that finding a working
drive will be most difficult. Heaven knows, mine died years ago.
--Chuck
3:13 p.m.
On 07/21/2018 02:43 PM, Carlo Pisani wrote:
thus, MO drive units are not reliable?
At least not the later PMC ones. I remember that my drive wasn't even 6
months old when it died. PMC's policy was to replace it with a
"refurbished" (read: used) replacement. That one barely lasted a month.
PMC then stated that their backlog on replacements was something like
12 weeks. I wrote the cost of the drive off and moved on. PMC ceased
operation shortly thereafter.
Mind you, I was using the drive only for testing, so fortunately no
important data was stored there.
I note that the southern California operation that bought the bankruptcy
sale stock is still in operation and offers a refurb Apex drive for
about $250 with a 30-day warranty.
No Thanks.
--Chuck
11:56 p.m.
The last generation 5.25" 4.x GB MO drive was unreliable which is why they
never went bigger I think. I have a bunch of 5.25" drives from a few makers
and all work.
-----Original Message-----
From: Carlo Pisani via cctalk
Sent: Saturday, July 21, 2018 5:43 PM
To: Chuck Guzis ; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: how good is the data reliability with CD ROM and DVD RAM?
thus, MO drive units are not reliable?
2018-07-21 23:34 GMT+02:00 Chuck Guzis via cctalk <cctalk at classiccmp.org>:
On 07/21/2018 02:12 PM, TeoZ via cctalk wrote:
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
I have old IBM MO Worm disks that are still
readable, same with all my
MO disks (3.5" 130MB, 5.25" 1.3GB) but drives can be iffy. I would bet
that MO media will outlast us all while finding a drive to read them
will be a problem.
I've got a few old PMC Apex 4GB disks. I suspect that finding a working
drive will be most difficult. Heaven knows, mine died years ago.
--Chuck
23 Jul
23 Jul
4:57 a.m.
On 07/21/2018 10:14 AM, Carlo Pisani via cctalk wrote:
hi
yesterday I was shocked by a couple of videos on Youtube where guys
pointed out their negative experiences with CD ROM and DVD RAM as
media for their own backup.
They complained their data completely lost after 5 years of storage in
CD ROMs, pointing out that their CDs were perfectly conserved and kept
clean without scratches, but all the data is gone lost since the media
is unreadable.
I've found in the past that problems with CDs are two-fold:
1) Deterioration of the media itself (which was particularly bad in the
early days)
2) Incompatibilities with media and/or the burning process across drives
and platforms.
The latter cropped up time and again, enough that I decided it was too
risky to keep data on CD because I might want to come back to it 5 or 10
(or more) years later and find that no hardware that I had available was
capable of reading it.
I don't know if DVD is any better; I developed a deep mistrust of any
optical media and so I avoid it except for transient stuff where there's no
alternative.
cheers
Jules
24 Jul
24 Jul
10:55 a.m.
On 7/21/18 9:14 AM, Carlo Pisani via cctalk wrote:
what is your experience?
I personally have had
reasonable success with CD-Rs.
I used Verbatim Blue CD-Rs for general storage back when I had a single
6.4 GB drive in '98. I have recently read the contents of all the
surviving disks with no problems that weren't resolved by a damp
washcloth gently wiping the underside of the disk.
I do seem to recall I had one disk that failed within a few months from
what seemed to be fungus or rot. I never knew. I got rid of it quickly.
All the other disks that I burned at 1x have lasted the better part of
20 years.
Honestly, I have more concern about functional CD-ROM drives more so
than I do the media. More and more machines I'm around don't actually
have a drive capable of reading CD-ROMs.
I was also exposed to some people using the El-Cheapo light (faint)
green CD-Rs and they would end up having problems reliably reading from
them a week or two later. I think they usually burned them as fast as
their drive would allow. To me, old AOL floppy disks were more reliable
than the light green CD-Rs burned at high speed.
I would only tolerate light green burned at 1x if I needed to move bulk
data between machines and networking was not an option. Once the data
was there, I considered the CD-R to be dead and frequently physically
destroyed it.
--
Grant. . . .
unix || die
11:33 a.m.
On Jul 24, 2018, at 10:55 AM, Grant Taylor via cctalk
<cctalk at classiccmp.org> wrote:
For me, the Verbatim DataLifePlus has always been the disks that I trust. Though at this
point I should review what is on them and move the data to online archives if I care about
it. Realistically a lot is old backups. So far I?ve never had a problem with them,
except bad burns on a flaky drive or system.
I have used cheap blanks for Linux installs, or to give someone copies of my photos.
Zane
On 7/21/18 9:14 AM, Carlo Pisani via cctalk
wrote:
what is your experience?
I personally have had reasonable success with CD-Rs.
I used Verbatim Blue CD-Rs for general storage back when I had a single 6.4 GB drive in
'98. I have recently read the contents of all the surviving disks with no problems
that weren't resolved by a damp washcloth gently wiping the underside of the disk.
I do seem to recall I had one disk that failed within a few months from what seemed to be
fungus or rot. I never knew. I got rid of it quickly.
All the other disks that I burned at 1x have lasted the better part of 20 years.
Honestly, I have more concern about functional CD-ROM drives more so than I do the media.
More and more machines I'm around don't actually have a drive capable of reading
CD-ROMs.
I was also exposed to some people using the El-Cheapo light (faint) green CD-Rs and they
would end up having problems reliably reading from them a week or two later. I think they
usually burned them as fast as their drive would allow. To me, old AOL floppy disks were
more reliable than the light green CD-Rs burned at high speed.
I would only tolerate light green burned at 1x if I needed to move bulk data between
machines and networking was not an option. Once the data was there, I considered the CD-R
to be dead and frequently physically destroyed it.
--
Grant. . . .
unix || die
11:42 a.m.
I wrote a lot of DDS2 and DDS3 tapes back in the day. When my DDS3 drive
broke, I got another drive. I found out that my first drive was seriously
out of calibration, and though it could read its own tapes, other drives
could not. All the data was gone.
I'm considering getting an LTO drive, but I won't do it unless either I buy
two drives, or find someone else with the same generation LTO drive who
would like to exchange encrypted backup tapes for verification.
11:46 a.m.
I have a brand new DLT drive for sale
brand new, it's SCSI, 2U
2018-07-24 20:42 GMT+02:00 Eric Smith via cctalk <cctalk at classiccmp.org>:
I wrote a lot of DDS2 and DDS3 tapes back in the day.
When my DDS3 drive
broke, I got another drive. I found out that my first drive was seriously
out of calibration, and though it could read its own tapes, other drives
could not. All the data was gone.
I'm considering getting an LTO drive, but I won't do it unless either I buy
two drives, or find someone else with the same generation LTO drive who
would like to exchange encrypted backup tapes for verification.
11:51 a.m.
On 07/24/2018 12:42 PM, Eric Smith via cctalk wrote:
I wrote a lot of DDS2 and DDS3 tapes back in the day.
When my DDS3
drive broke, I got another drive. I found out that my first drive was
seriously out of calibration, and though it could read its own tapes,
other drives could not. All the data was gone.
Ouch!
That sounds like a common type of problem, namely single point of
failure on alignment. I think I've heard of the same for floppy drives too.
I'm considering getting an LTO drive, but I
won't do it unless either I
buy two drives, or find someone else with the same generation LTO drive
who would like to exchange encrypted backup tapes for verification.
Valid concern.
I would also like to confirm that your drive can also read tapes from
your friend's alternate drive.
I'd really prefer if it was a trio of drives. But that's even more
expensive / unlikely / difficult to achieve goal.
--
Grant. . . .
unix || die
2339
days inactive
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days old
72 comments
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participants (24)
-
abuse＠cabal.org.uk -
aek＠bitsavers.org -
als＠thangorodrim.ch -
carlojpisani＠gmail.com -
cclist＠sydex.com -
cctalk＠beyondthepale.ie -
cctalk＠gtaylor.tnetconsulting.net -
cctalk＠ibm51xx.net -
chd＠chdickman.com -
cisin＠xenosoft.com -
elson＠pico-systems.com -
ethan＠757.org -
healyzh＠avanthar.com -
hollandia＠ccountry.net -
imp＠bsdimp.com -
jfoust＠threedee.com -
jim.manley＠gmail.com -
jules.richardson99＠gmail.com -
mtapley＠swri.edu -
oltmansg＠gmail.com -
paulkoning＠comcast.net -
phb.hfx＠gmail.com -
spacewar＠gmail.com -
teoz＠neo.rr.com