[libvirt-users] Using virsh blockcopy -- what's it supposed to accomplish?

[Kashyap Chamarthy]

On Thu, Jan 08, 2015 at 06:14:05PM -0600, Gary R Hook wrote:
> On 1/8/15 2:48 PM, Eric Blake wrote:
> >On 12/23/2014 05:24 PM, Gary R Hook wrote:
> >>I read that article.
> >>
> >>Now shut down the domain (post-pivot) which is using the new disk file,
> >>and start it up, without using a block device. This is the part that no
> >>one seems to write about, nor do I see that in your example. But thank
> >>you very much for your help and your articles; very much appreciated.
> >
> >What do you mean by "without using a block device"?  Are you trying to
> >revert back to the pre-copy file?  Libvirt is supposed to rewrite the
> >domain XML to reflect the end result of breaking the mirroring (whether
> >you pivot or abort back to the original), and further starts of the
> >domain should use the correct current file (which might not be the file
> >that the earlier domain start used).  If you abort a blockcopy before it
> >is complete, the destination is useless (incomplete).  If you end a
> >blockcopy after it reached mirroring phase, the the file that you
> >abandon (whether the original if you pivoted, or the destination if you
> >aborted) is a point-in-time snapshot of the disk at the point you quit
> >the mirroring; this disk snapshot is liable to need fsck and otherwise
> >have inconsistencies unless you also ensured that guest I/O was stable
> >before the point of breaking the mirroring (basically, using guest-agent
> >freezing and thawing around the operation).
> >
> 
> I've responded to Kashyap about this with the solution to my problem. It was
> a usage error.

I think you're referring to the comment you made on this post[1]. I
fixed the things you pointed out. Thanks for the review, Gary.


[1] http://kashyapc.com/2014/07/06/live-disk-migration-with-libvirt-blockcopy/
 

-- 
/kashyap