[virt-tools-list] Would this suffice to backup a local vm image?

[Richard W.M. Jones]

On Wed, Feb 02, 2011 at 09:35:12AM -0500, Kenneth Armstrong wrote:
> It will be safer when it is shutdown.  That's what I was intending.
> 
> Right now, I'm just asking about local storage (from a hard drive that
> the host is on, where the original image is stored, to an external USB
> hard drive).  I tried this out, and it seemed to work fine.  I would
> just copy the backed up disk image to /var/lib/libvirt/images and edit
> the host's xml file to reflect the new storage location, and bring it
> up in virt manager.

OK, but as long as you understand that this is *not* safe if the guest
is live.  This is because 'dd' or 'cp' are not instantaneous snapshots
of the whole disk.

If instead the disk was on LVM, iSCSI or an advanced filesystem like
XFS/btrfs, then you could do an instantaneous snapshot, which would be
safe for a live VM.  Or at least, would produce a crash-consistent
image which is safe for many purposes excluding some database
applications.

> I would definitely use backup software from within the guest for
> primary back ups, I was just trying to find another avenue as well by
> utilizing the guest vm's inherent portability of it just being a
> couple of files that constitute the vm.

Good.  Installing backup software in the guest is always the best way.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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