On Tue, 25 Nov 2014 22:42:38 -0700
Chris Murphy [off-list ref] wrote:

On Mon, Nov 24, 2014 at 9:07 PM, Joe Lawrence [off-list ref] wrote:

quoted

Does anyone know how its possible to determine which side of an LVM RAID 1
is the stale partner during RAID resync?

In ordinary MD RAID, I believe you can check
/sys/block/md0/md/dev-XXX/state, but LVM RAID seems to hide those files
when leveraging the MD code.  I've looked though pvs/vgs/lvs manpages, but
can't figure anything out there either.

Rather indirectly: iotop which will show you which devices are mostly
being read from and written to.

# lvs -a -o copy_percent
Anything less than 100% is syncing. I think.

From the manpages I see the following attribute bits:

* lvs, lv_attr bit Volume Health: (p)artial
* vgs, vg_attr bit (p)artial: one or more physical volumes belonging
       to the volume group are missing from the system
* pvs, pv_attr bit (m)issing

along with the lvs copy_percent (is this similar to sync_percent) that
you mentioned.  That's about it.

Since there seems to be no real underlying MD device, I'm assuming that
ioctls are out of the question as well.

-- Joe