10 Feb
2006
10 Feb
'06
1:50 p.m.
Don't the Unix-based OS's have a similar
capability with the 'dd'
function, BTW?
dd will fail on the first bad block on the device.
It also wouldn't work if the SCSI device is using a sector size
different from
what the raw device driver is expecting.
Getting disc images of these discs may be more difficult than you
might initially
think, because they aren't likely to be either SCSI or IDE. If they
are ST506, you
have to have a disc interface that matches the sector encoding. It is
unlikely
you are going to be able to find one that will match using commodity
ISA controllers.
If the computers are working, you'll probably have to write some code
to send the
data out through some interface on the computer, like a serial port,
dealing with
the possiblity of bad sectors. The 7300 was common enough that I
would think a
program exists somewhere to to that.
10 Feb
10 Feb
1:57 p.m.
On Fri, 2006-02-10 at 10:50 -0800, Al Kossow wrote:
Not necessarily. most dd's have "conv=noerror" which just put a block
of nulls wherever there's errors.
Brian
Don't the
Unix-based OS's have a similar capability with the 'dd'
function,
BTW?
dd will fail on the first bad block on the device. 
1:58 p.m.
Yeah, I've run into that as well, dd is not very forgiving....
Curt
Al Kossow wrote:
--
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Checked by AVG Free Edition.
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Don't the Unix-based OS's have a similar
capability with the 'dd'
function, BTW?
dd will fail on the first bad block on the device.
It also wouldn't work if the SCSI device is using a sector size
different from
what the raw device driver is expecting.
Getting disc images of these discs may be more difficult than you
might initially
think, because they aren't likely to be either SCSI or IDE. If they
are ST506, you
have to have a disc interface that matches the sector encoding. It is
unlikely
you are going to be able to find one that will match using commodity
ISA controllers.
If the computers are working, you'll probably have to write some code
to send the
data out through some interface on the computer, like a serial port,
dealing with
the possiblity of bad sectors. The 7300 was common enough that I would
think a
program exists somewhere to to that.
--No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.375 / Virus Database: 267.15.5/256 - Release Date: 2/10/2006
2:54 p.m.
dd will fail on the first bad block on the device.
Not if you use conv=noerror,sync. But unless your bs= value equals the
sector size, a bad block will take out some nearby blocks as well when
run that way; you really want something better tuned to imaging disks,
something that in particular steps down to smaller blocksizes when it
gets a read error, so as to recover as much as it can.
Of course, this all presumes that there is a Unix variant for a machine
to which the disks can be attached....
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3:05 p.m.
dd will fail on the first bad block on the
device.
Not if you use conv=noerror,sync. But unless your bs= value equals the
sector size, a bad block will take out some nearby blocks as well when
run that way; you really want something better tuned to imaging disks,
something that in particular steps down to smaller blocksizes when it
gets a read error, so as to recover as much as it can.
Of course, this all presumes that there is a Unix variant for a machine
to which the disks can be attached....
6743
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