[linux-lvm] Solving the "metadata too large for circular buffer" condition

[Andrew Gideon]

On Wed, 24 Nov 2010 17:02:36 -0600, Ray Morris wrote:

>     If you have two redundant PVs or free space, one could move LVs in
> order to empty an older PV, then recreate it with larger metadata.
> pvmove can be used to move active LVs, or dd is much faster for inactive
> ones.

I don't have much free space on the storage device.  To get this would 
take a fair bit of time in that I'd need to add new drives and 
incorporate them into the RAID set.

But I do have *some* space thanks to "rounding errors" (or "fudge 
factor").  It's not enough to move much data around, but I could build a 
couple of small PVs for use primarily as metadata repositories.

Does this make sense?

In the long term, as I do add new disks, I can create new "real" PVs with 
the larger metadata segments, increasing the redundancy.  Ultimately, I 
can get ahead of the game and start pvmove-ing segments off the PVs on 
which I'd have disabled the metadata because the space allocated is too 
small.

But, in the short term, I'm looking to see how I can most quickly return 
this device to "full service" (being able to extend or add volumes).  And 
that seems to be using a pair of tiny PVs as metadata-only.  If that 
makes sense.

Does it?

Thanks...

	Andrew