It's been occuring to me that in a server environment, especially while
using RAID, it would be nice to be able to give an absolute specification
of the drives such as A00I00L00P00 in a SCSI environement.
Where Axx is the SCSI adapter number starting with 0 and incrementing by
one, Ixx is the SCSI ID on that adapter, Lxx is the LUN#, Pxx is the
partition number, etc.
I've had a number of instances where I've moved drives around in the
"middle" of the chain and then had to go and fix up the /etc/fstab and the
/etc/raidtab (before I moved to RAID 0.90 alpha and autodetect) before it
would start again. Surely not impossible or very time consuming, but
surely not necessary if absolute devices existed. I know that a number
(all?) of flavors of Unix have such a system.
Perhaps the /dev/sda, sdb, etc system is good/convenient for those used to
the DOS/Windows lettering convention but on a server it's usually just a
pain in the butt for me.
Now, before someone yells at me for being off topic :), does anyone know
how the Linux software RAID handles it if a new drive was inserted in the
SCSI system in a device letter preceding a RAID configured for
autodetection? Is it smart enough to compensate or is it going to fail? I
would test it but I only run software RAID-5 at home and I have no spare
drives there to fiddle with. That was the question that got me thinking
along those lines.
Does anyone know if there any reason why we don't have both absolute and
relative SCSI device numbering in the kernel? (Other then that no one's
bothered to write it :))
Best,
Sean
