[Discuss] Disk numbering

[matt at ciranttechnologies.com (Matt Iavarone)]

On 10/01/2011 10:26 AM, Jerry Feldman wrote:
> 2 weeks ago when I added a new 1.5TB ($49) HD to use as backup, my
> drives were numbered sda, sdd, sde, and sdf. This prompted me to rewrite
> my weekly disk health script to discover what drives are on my system.
> All well and good. My /etc/fstab uses only UUID as does my RAID1. I shut
> my system down last week when I went out of town for a couple of days,
> and I found that the drives were renumbered again. I don't recall the
> exact numbering, since I don't have anything that uses the drive numbers
> other than my health script.  When I returned, I noticed an I/O error on
> the new drive so I spent hours running fsck to bypass the bad blocks and
> fix any errors. I'm watching closely to see over the next few days in
> case I need to return the drive. After the fsck was completed, and the
> drive tested good, I rebooted, and this morning I noticed another
> renumbering (sda, sdb, sdc, sdd). The backup drive that was repaired is
> still /dev/sdc. Now sda and sdb are the RAID1 pair.
>
> I guess I am just ranting because I know the kernel assigns the drive
> numbers at boot time and I don't need to know anything about the drive
> numbers unless I need to run something manually.
>

If you have dependencies on the disk lettering, then you can use udev 
rules to force them.


Matt Iavarone
Lead Engineer
Cirant Technologies
matt at ciranttechnologies.com <mailto:matt at ciranttechnologies.com>
(866) 838-4784
<http://www.ciranttechnologies.com>