Disk controller detection order

[Don Buchholz]

Christopher Mocock wrote:
> pbdlists at pinboard.com wrote:
>> Hi Chris,
>>
>> I have an old machine with SCSI disks on an adaptec controller and
>> recently added three SATA disks with a promise SATA controller add-on
>> card. With this machine I have the same issue. The machine boots off
>> the SCSI disk and sees this as sda, while during the installation it
>> assigns sda/sdb/sdc to the three SATA disks and sdd to the SCSI disk.
>>
>> I believe that somehow controller detection in the installation kernel
>> and the installed kernel is not in the same order.
> 
> Interesting. I can't really do the hack you mention because my custom 
> spin has to go on lots of machines with different numbers of drives so I 
> can't make any such assumptions. Thanks for the info anyway.
> 
> The only workaround I can think of is disconnecting all the drives from 
> the RAID card, then doing the installation, then replacing the drives. 
> Far from ideal.
> 
> Not really sure where to go from here.
> 
> 

Here's a shot in the dark ... would UDev custom rules solve
your problem?

I can't say I've spent any serious time doing udev customization,
we were looking at hotplug handling, and I ran across these pages
while researching that topic.

If I read it correctly, you could insert your own rules to override
the default naming.  However, since you state your environment has
serious challenges with non-uniform hardware configurations, this
might just be another dead end.

Of course, the UDev management might just kick in too late during
a normal system boot ...

My notes w/ some URLs are below.

- Don


=================================

   -- From:  http://www.wlug.org.nz/UDev
     ...
       udev is the UserSpace-based replacement for DevFs, an obsolete Linux
       Kernel Module that creates entries for available devices in /dev.
       udev is available in Kernel 2.5 and newer and uses HotPlug and the
       SysFs FileSystem.

       The home page for udev is at:
          http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html

       See also:

         * Red Hat Magazine - Configuring Devices with udev
             -- http://www.redhat.com/magazine/002dec04/features/udev/
         * Writing udev rules
             -- http://www.reactivated.net/udevrules.php
         * Gentoo Customizing udev HOWTO
             -- http://gentoo-wiki.com/HOWTO_Customizing_UDEV
     ...