Xen users - Jan 2012 - Can not boot linux domUs on new SAN

We are currently converting to a new SAN. I;m in the process of moving
linux VMs from the old SAN to the new one. These are mostly sles10 and
sles11 with simple ext3 file systems. 

Basically this process involves downing the VM and assigning the domU
disk to the new SAN, which can attach to it as a pass through type disk.
From there I can create a copy of the disk on the new SAN. I can then
assign this new copy to the xen hosts on the new SAN. All the
information within the disk remains the same, but the underlying scsi ID
changes. 

I can see the disk fine on the xen hosts attached to the new SAN. The VM
configs all use standard xvda assignment in their configs, but I am
unable to start the VMs on the other side. I always get an error:
Error: Boot loader didn''t return any data!

If I manually mount the disk I can read the content of the disk without
any problem. 

I''ve also done an fsarchiver backup/restore to a newly created SAN disk
and it boots up fine. 

Any ideas why I can''t boot the copies?

xen hosts are running sles11sp1 with xen 4.0.2_21511_04-0.5.1

Any ideas are appreciated. Please let me know if I can provide any
further info. 

Thanks,
James

Is the pass-through disk listed first in the disk=[*] line of the xm config?

pygrub will only scan the first disk in disk=[*]

Post the xm config and menu.lst if you like

-- 

Mark



----- Original Message -----
From: James Pifer <jep@obrien-pifer.com>
To: Xen list <xen-users@lists.xensource.com>
Cc: 
Sent: Wednesday, January 18, 2012 2:30 PM
Subject: [Xen-users] Can not boot linux domUs on new SAN

We are currently converting to a new SAN. I;m in the process of moving
linux VMs from the old SAN to the new one. These are mostly sles10 and
sles11 with simple ext3 file systems. 

Basically this process involves downing the VM and assigning the domU
disk to the new SAN, which can attach to it as a pass through type disk.
From there I can create a copy of the disk on the new SAN. I can then
assign this new copy to the xen hosts on the new SAN. All the
information within the disk remains the same, but the underlying scsi ID
changes. 

I can see the disk fine on the xen hosts attached to the new SAN. The VM
configs all use standard xvda assignment in their configs, but I am
unable to start the VMs on the other side. I always get an error:
Error: Boot loader didn''t return any data!

If I manually mount the disk I can read the content of the disk without
any problem. 

I''ve also done an fsarchiver backup/restore to a newly created SAN disk
and it boots up fine. 

Any ideas why I can''t boot the copies?

xen hosts are running sles11sp1 with xen 4.0.2_21511_04-0.5.1

Any ideas are appreciated. Please let me know if I can provide any
further info. 

Thanks,
James


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On Thu, Jan 19, 2012 at 10:01 AM, Mark Pryor <tlviewer@yahoo.com>
wrote:
> Is the pass-through disk listed first in the disk=[*] line of the xm
config?
>
> pygrub will only scan the first disk in disk=[*]
>
> Post the xm config and menu.lst if you like
Also, running pygrub manually (e.g. pygrub -i
/dev/path-to-your-san-disk) should give more info what''s wrong.
Perhaps pygrub doesn''t recognize some entry it it''s grub menu,
or the
fs where /boot is located is not supported.

-- 
Fajar