[Gluster-devel] Gluster 2.0.8 and Xen

Nathan Stratton nathan at robotics.net
Thu Nov 12 19:14:35 UTC 2009

On Thu, 12 Nov 2009, Brian Hirt wrote:

> Nathan,
> This might be a side effect of open files not being replicated.  If the 
> VM has any open files that it has written to, none of the changes will 
> be propagated to the other node until the file is closed.  If a gluster 
> node goes down, and that's the node with the modified open file, then 
> you are out of luck.  If the VM reopens the file while the correct node 
> is down, it will get the out of date file on the replicated node.  From 
> there, the VM might go bonkers, or maybe it writes to that file also, 
> then you end up with a split brain where you have two different copies 
> on two different nodes.

Ah ha! So even tho I am using distribute since I am using xen with file 
the file is opened and only accesses one node? That would explain a LOT of 

Is there any way to see what node it is using for what xen file?

> 3.0 is supposed to address the open file replicate, though I haven't 
> had a chance yet to test it to see if it fixes all the problems we were 
> having with 2.08.   You might want to check out  3.0pre1 and see if that 
> makes any difference.

I just have been very scared about going with a pre1 release! At the same 
time, I must find a stable xen storage solution and 3.0pre1 may offer me 
more then I can get with current 2.0.8 anyway.

Nathan Stratton                                CTO, BlinkMind, Inc.
nathan at robotics.net                         nathan at blinkmind.com
http://www.robotics.net                        http://www.blinkmind.com

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