11 May
2010
11 May
'10
6:48 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