> -----Original Message-----
> From: linux-cluster-boun...@redhat.com 
> [mailto:linux-cluster-boun...@redhat.com]
> On Behalf Of Geovanis, Nicholas
> Sent: Wednesday, December 07, 2011 12:23 PM
> >> We ditched CLVM but kept GFS.  It felt like CLVM had too many limitations 
> >> to make
> it worthwhile.
> 
> Would you elaborate on this for me please? I understand the "damn, forgot to 
> start
> clvmd on that node...." type of annoyance, but what were your burning issues? 
> I'm not
> convinced that there's a performance drawback which is specifically 
> clvmd-related, but
> maybe I'm naïve. Thanks....Nick G

At the time there was no snapshot support.  That was the big missing feature 
for us.

We also tried using pvmove, and had problems with it.  It was very slow, and 
eventually stopped altogether complaining about a lock.  I tried activating 
LV's exclusively and it didn't help.  Later I found that that in drastic 
situations, I could remove the "clustered" bit temporarily, make my changes, 
then revert to a clustered volume (recognizing this is dangerous when the 
volume is shared).

At times, running simple commands like "lvs" became very slow, or stopped 
completely.  Restarting the node would clear it up.  When this occurred, the 
cluster would otherwise appear normal.

To be fair, it was a few years ago when we were evaluating this, on 5.2 I 
think.  It's likely some of the bugs have been worked out.   We didn't have a 
lot of motivation to work through them as long as we could fall back on the SAN 
for the functionality we needed.

Red Hat has a tendency I think to release features just a little before they 
are ready (sometimes with caveats, like the GFS2 preview release).  This is 
good for users who are evaluating the technology.  For production however, we 
need stability above all else.  Since about 5.3, GFS has worked very well for 
us.  Based on our experience with early 5.x releases, I'm not in any hurry to 
move to 6.x.

-Jeff



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