11 May
2010
11 May
'10
6:22 p.m.
I have an ACARD AEC-7720U that I have been using in a VS4000/90 with
good results. I am trying to compare different versions of NetBSD. I
would like to split a 30GB IDE drive into 4 or so logical units. I don't
know much about SCSI really, but I believe that it is possible to divide
some drives into individually addressable logical drives, sort of like
partitions, but at the hardware level.
Can somebody enlighten me on SCSI LUNs, at least as far as they apply to
dividing disks? Does SCSI define how to divide a disk, or is that
proprietary to the drive? Since in my case the bridge is the "drive"
would I need a specific utility from ACARD for this?
-chuck
11 May
11 May
6:43 p.m.
----- Original Message -----
From: "Charles H Dickman" <chd at chdickman.com>
To: <General at adelaide.photojim.ca>;
"Discussion at adelaide.photojim.ca:On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Tuesday, May 11, 2010 4:22 PM
Subject: scsi-ide bridge LUNs
I have an ACARD AEC-7720U that I have been using in a
VS4000/90 with good
results. I am trying to compare different versions of NetBSD. I would like
to split a 30GB IDE drive into 4 or so logical units. I don't know much
about SCSI really, but I believe that it is possible to divide some drives
into individually addressable logical drives, sort of like partitions, but
at the hardware level.
I am no SCSI expert... but the only use to which I've seen SCSI LUNs put is
in multi-tape backup units and CD changer units. (I have a 5-disc Nakamichi
SCSI CD changer somewhere... it might be 6-disc. No matter.)
The LUNs in this case refer to the unique media installed in the device.
Jim
9:48 p.m.
On 5/11/10 6:22 PM, Charles H Dickman wrote:
I have an ACARD AEC-7720U that I have been using in a
VS4000/90 with
good results. I am trying to compare different versions of NetBSD. I
would like to split a 30GB IDE drive into 4 or so logical units. I don't
know much about SCSI really, but I believe that it is possible to divide
some drives into individually addressable logical drives, sort of like
partitions, but at the hardware level.
Can somebody enlighten me on SCSI LUNs, at least as far as they apply to
dividing disks? Does SCSI define how to divide a disk, or is that
proprietary to the drive? Since in my case the bridge is the "drive"
would I need a specific utility from ACARD for this?
SCSI (at least common implementations of it) doesn't do this. LUNs
are for things like volumes in RAID arrays and such. Picture a large
RAID system (using any type of disks) interfaced to a host system via
SCSI. These typically have multiple "volumes" or logical disks, that
show up on the same SCSI ID but are accessed using different LUNs.
You're going to get the partitioning functionality you're looking for
using just a bare SCSI interface. What you need is a SCSI RAID
controller (whether you're using its redundancy and fault-tolerance
capabilities or not) to carve up one physical volume into multiple
logical volumes.
-Dave
--
Dave McGuire
Port Charlotte, FL
13 May
13 May
3:06 a.m.
On Tue, 11 May 2010 18:22:30 -0400
Charles H Dickman <chd at chdickman.com> wrote:
I would like to split a 30GB IDE drive into 4 or so
logical units.
I don't know much about SCSI really, but I believe that it is possible
to divide some drives into individually addressable logical drives,
sort of like partitions, but at the hardware level.
The SCSI bridge could do this.
As already mentioned some RAID arrays
split an array into multiple volumes and present each volume to the
host as a LUN. It should be no problem doing this with a single disk.
But the controler must support this and most likely the ACARD doesn't.
I am trying to compare different versions of NetBSD.
You can do this: Make a sd0a partition that holds your primary
instalation and the kernels of your different other versions. Make a
partition for each additional version you wane test, e.g. sd0d,
sd0e, ... and hardcode these as root-partition in your individual
kernels:
config netbsd root on sd0e type ffs
This way you can have multiple parallel instalations, each in a
separate partition. Boot selection is done by chosing a different
kernel to boot on the boot prompt.
--
tsch??,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/
5133
days inactive
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3 comments
4 participants
participants (4)
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chd＠chdickman.com -
jim＠photojim.ca -
jkunz＠unixag-kl.fh-kl.de -
mcguire＠neurotica.com