[ale] Motherboard Drives First, Please!

[Sean C. McCord]

First; please don't reply with a new thread.  It messes up the nice,
pretty threading that some of us use.  :)

On Tue, Feb 10, 2009 at 12:23:15PM -0500, Jeff Hubbs wrote:
> Supermicro X7DBE+ mobo, two 3ware SAS RAID controllers and one 3ware 
> SATA raid controller, four SATA drives on the mobo. How to make sda-sdd 
> always be the mobo drives? I'm going to test JBODding the controllers 
> and I want the four drives that work the OS to always appear as sda-sdd.

You can force the order by making each of the driver modular and loading
the modules in the order you want.  That, of course, means that you're
relegated to either a initial ramdisk image or a root filesystem on the
"first" one and build it into the kernel.

A better method, however, would be to NOT use the /dev/sdX name
references and use /dev/disk/by-id or /dev/disk/by-uuid method.  These
will stay consistent even across controllers.
 
> I've already tried disabling bootable flags on the controllers and 
> fooling around with the boot order in the mobo BIOS but it's not 
> working.  FWIW, the Gentoo LiveCD puts sda on the mobo's SATA0 like I'd 
> expect.

That is because the /dev/sdX lettering is simply a first-come,
first-serve order by driver load.  In order words, the first disk of the
first-loaded driver gets "sda", and so forth.

--
Sean C. McCord