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Date: Wed, 3 Oct 2007 20:18:21 +0100
From: Alasdair G Kergon <agk@redhat.com>
Subject: Re: [linux-lvm] Where to report bugs?
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To: LVM general discussion and development <linux-lvm@redhat.com>

On Wed, Oct 03, 2007 at 08:31:28PM +0200, Hannes Dorbath wrote:
> 8. Use vgreduce --removemissing to get VG data up again
> LV origin is gone and can only be brought back from backup with
> vgcfgrestore.
 
Right.  So you're asking for vgreduce --removemissing to be enhanced
to consider just removing the snapshot and leaving behind the LV if
it possible.  Seems reasonable.

The logic that needs improving is in _remove_lv() in tools/vgreduce.c
if anyone wants to have a go at fixing it.

                /* Use the origin LV */
                lv = snap_seg->origin;

Perhaps it should have a second variable to hold the origin, and in the
following loop only deal with the current cow instead of all of them.

(It needs to handle two cases: origin LV is gone=>loop and remove all snapshots
as well as the origin; snapshot LV only is gone=>only remove this snapshot.
Maybe push the remove_snapshot code into a separate function then call
it from two places for the two different cases, avoiding the loop for the
one snapshot only case.)

Alasdair
-- 
agk@redhat.com