[Fedora-xen] How to backup a Domu filesystem (on LVM) from Dom0 on Fedora 8 ?

[Markus Armbruster]

Anne Facq <annefacq at crpp-bordeaux.cnrs.fr> writes:

> Aaron Clark wrote:
>> Anne Facq wrote:
>>> Hello
>>>
>>> I use XEN on Fedora 8 with Domu on a LVM partition.
>>>
>>> Before, on Fedora Core 6, I could backup each Domu by directly
>>> mounting the filesystem of the Domu (mount /dev/vg00/lvfoo /mnt)
>>> and then running dump on it.
>>>
>>> On Fedora 8, I can't mount directly the filesystem of the Domu, so
>>> I 
>>
>> Pardon if this is a dumb question, but why not?
>
> Because in Dom0 the device for a paravirt Domu (/dev/vg00/lvfoo in my
> case) is mapped to a virtual disk /dev/xvda (I created the Domu with
> virt-install), and the only way I found to mount this Domu filesystem,
> is to :
> - get the size of the boot sector of /dev/vg00/lvfoo
> 	(with fdisk -ul /dev/vg00/lvfoo)
> 	= 63
> - compute the offset (multiply by block size)
> - specify this offset to the mount command :
> mount -o offset=32256 /dev/vg00/lvfoo /mnt/
>
> As I can't specify an offset to dump, the command "dump 0 -f lvfoo.dump
> /mnt" doesn't work.

Shot from the hip: losetup with the offset?

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