[Fedora-xen] Slightly off-topic question about Xen+LVM

[Aaron Metzger]

Stephen C. Tweedie wrote:
> Hi,
> 

> 
> Well, in general it should work.. we'd need to see the error to know if
> there's a special-case you've fallen into.
> 

A follow-up to describe what I have found regarding Fedora 8 and my 
attempts to use LVM snapshots to hold Xen guest images.  Maybe it will 
help others.

In general, I was unable to create any LVM snapshot with an out of the 
box configuration of a 64 bit Fedora 8 until I manually loaded the 
"dm-snapshot" kernel module.

   modprobe dm-snapshot

Then, I was able to create a snapshot volume and all seemed fine until I 
rebooted the machine.  The boot sequence failed with a message about 
"unable to expand snapshot volume" which I assume was caused again by 
the lack of the "dm-snapshot" module.  I used the rescue disk to remove 
the snapshot volume and was able to boot my machine once again.

I found a number of postings on the debian mailing lists from 2005 
regarding the same issue and peoples attempts to get the "dm-snapshot" 
module to load during boot.

I played around with modules.conf.d configuration to try to get the 
module to load on boot but didn't have any success.

Do I need to make a custom boot/initrd script or am I on the wrong 
track?  Ideas are welcome.

In the mean time, I have resigned myself to just not ever rebooting the 
machine while any snapshot volumes exist.

--
Aaron