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Re: [Xen-users] xen + centos + areca raid issues

To: muecke@xxxxxxxxxx
Subject: Re: [Xen-users] xen + centos + areca raid issues
From: "Anand Gupta" <xen.mails@xxxxxxxxx>
Date: Tue, 16 Oct 2007 17:36:54 +0530
Cc: Xen Users <Xen-users@xxxxxxxxxxxxxxxxxxx>
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Thanks for the quick response Artur.

The reason there is nothing in the config file about the kernel is because of pygrub and centos's way to put the kernel inside the domU (atleast thats what i had learnt by reading the thread on this list)

I cannot mount the domU image file since it contains LVM volumes in it. Here is the partition structure of the image file aaa.

Disk aaa: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System
  aaa1   *           1          13      104391   83  Linux
  aaa2              14        1300    10337827+  8e  Linux LVM
Partition 2 has different physical/logical endings:
     phys=(1023, 254, 63) logical=(1299, 254, 63)

I tried to use lvm tools to recognise the volume as well, however doesn't work. For this, i used the following

losetup /dev/loop0 /home/xen/aaa

Now the entire image is present as /dev/loop0. However when i try to run vgscan, it doesn't recognise the lvm volume at all.

On 10/16/07, Artur Mücke <muecke@xxxxxxxxxx> wrote:
Anand Gupta wrote:
> Also the Virtual Machine Manager under centos has stopped working. Does this
> mean i need to recreate these domU's ? Really confused here on how to go
> about it since the old domU has a lot of data in it, which is required and
> now the machine is down :(

There's nothing about your new kernel in your domU-Configuration. There
should be something like:
kernel  = '/boot/vmlinuz-2.6.18-5-xen-686'
poniting on the new compiled kernel.

Moreover you should copy the new kernel modules to e.g. /lib/modules/.

Dont worry about your data in the domU. You can mount your Image or the
according partition like this:

mount /dev/XdaX /mnt

mount -o loop /yourfolder/vm_disk.img /mnt

Maybe the best would be to create a new VM with xen-create-image.

Hope thats gonna help you a bit.



"There are 10 kinds of people in the world, those who understand binary
math, and those who don't."


Anand Gupta
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