On Mar 17, 2011, at 19:20 , Joel Maslak wrote:

> I'm seeing some differences in SCSI drive numbering in SL 6 / RHEL 6, compared to CentOS 5 / RHEL 5.  This means that on *some* of my servers, /dev/sdb is actually the first hard disk, which makes kickstarting a bit more annoying.  Does anyone know a way to reverse the order or similar easily?

We're using "pci=bfsort" for SL5 and "pci=bfsort nousb" for SL6 when kickstarting. The "pci=bfsort" is kept on the installed system, "nousb" isn't. Eventually, using /dev/disk/by-* will be the right solution, but for the time being these kernel parameters give us consistent device enumeration across SL5/6.

- Stephan

>  A parameter to grub to either remove the virtual floppy or reorder these would be handy, if someone knows of one.  Certainly I can disable the virtual floppy in these machines, but I'd rather not do that (it's needed for BIOS updates).
> 
> In CentOS 5 / RHEL 5, I would see disk configurations such as:
> 
> scsi 0:0:0:0: CD-ROM                     Virtual CDROM    1.00 PQ: 0 ANSI: 0 CCS
> scsi 1:0:0:0: Direct-Access              Virtual Floppy   1.00 PQ: 0 ANSI: 0 CCS
> scsi 2:0:0:0: Direct-Access     SEAGATE  ST973451SS       SM04 PQ: 0 ANSI: 5
> scsi 2:0:1:0: Direct-Access     SEAGATE  ST973451SS       SM04 PQ: 0 ANSI: 5
> scsi 2:1:0:0: Direct-Access     Dell     VIRTUAL DISK     1028 PQ: 0 ANSI: 5
> s
> sd 0:1:0:0: Attached scsi disk sda
> sd 2:0:0:0: Attached scsi removable disk sdb
> 
> Basically, sda was the internal RAID 1 disk array and sdb is the DRAC "virtual floppy".  This worked fine, and our scripts knew to expect sda as the first disk.  Note that these are identical systems, purchased at the same time and delivered together.
> 
> On SL 6 / RHEL 6, it reverses the order of sda and sdb:
> 
> scsi 0:0:0:0: CD-ROM                     Virtual CDROM    1.00 PQ: 0 ANSI: 0 CCS
> scsi 1:0:0:0: Direct-Access              Virtual Floppy   1.00 PQ: 0 ANSI: 0 CCS
> scsi 2:0:0:0: Direct-Access     SEAGATE  ST973451SS       SM04 PQ: 0 ANSI: 5
> scsi 2:0:1:0: Direct-Access     SEAGATE  ST973451SS       SM04 PQ: 0 ANSI: 5
> scsi 2:1:0:0: Direct-Access     Dell     VIRTUAL DISK     1028 PQ: 0 ANSI: 5
> sd 2:1:0:0: [sdb] Attached SCSI disk
> sd 1:0:0:0: [sda] Attached SCSI removable disk
> 
> (sdb becomes 1:0:0:0, sdb becomes 2:0:0:0)

-- 
Stephan Wiesand
DESY -DV-
Platanenenallee 6
15738 Zeuthen, Germany