CentOS - Mar 2008 - Boot from FC SAN CentOS 5.1 x86-64

Anything special needed to boot from a SAN in
CentOS 5.1 x86-64 ?

We have a new system running a QLA2342 FC HBA connected to
a SAN, have a volume exported to it and would like to boot
from it.

We PXEboot kickstart and that works, the installer sees
the disk, installs to it, and reboots. When GRUB tries to
load all it prints is "GRUB" and sits there.

When we try the Xen edition of CentOS 5.1, when GRUB tries
to load the screen goes black and the system reboots.

When we try VMWare ESX 3.5.0 it works perfectly, so the
BIOS configurations and the SAN config is good, something
specific with CentOS 5.1.

I see in the release notes that SAN boot is supported, but
doesn't give any special instructions.

Anyone else booting CentOS directly from a FC SAN ? Any
special considerations needed for multipathing and
stuff when booting ?

thanks

nate

On Mon, Mar 17, 2008 at 5:56 PM, nate <centos at linuxpowered.net> wrote:
>  I see in the release notes that SAN boot is supported, but
>  doesn't give any special instructions.
>
>  Anyone else booting CentOS directly from a FC SAN ? Any
>  special considerations needed for multipathing and
>  stuff when booting ?
Use the 'mpath' when you're installing, and that should pretty much
take care of it. The one issue that we had is that the Centos/RHEL
mpath option defaults to active/active pathing, so storage systems
that use active/passive (like our DS4700) can get angry unless you
change the configuration after install. Also, I've heard reports of
some folks having delays with older HBAs like the qla23xx, needed a
longer timeout than the 250 listed in /proc/scsi/scsi. I've not
confirmed this, and it could simply be related to the way the san is
cabled up or how the zones are defined.



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During times of universal deceit, telling the truth becomes a revolutionary act.
George Orwell