[Gluster-users] overzealous quota?

Ted Miller tmiller at hcjb.org
Wed Jan 29 15:54:23 UTC 2014


After concluding that:
Replica 2 + quorum = Low Availability
Replica 2 - quorum = split brain (learned the hard way)

I switched to replica 3 for my oVirt 2 host setup.

Since I have only 2 hosts under the control of oVirt (which wants a LOT of 
control), I ended up with
Replica 3 + quorum
Brick 1 on host 1
Brick 2 on host 2
Brick 3 on host 2

Not ideal, but at least there are 3 bricks to vote, and host 1 should be able 
to go down and still have a quorum.

What I find is that the situation is the same as replica 2 + quorum -- both 
hosts must be up in order for the volume to be accessible.
Symptom
gluster volume info: reports volume is started.
gluster volume status: reports 2 bricks, but no ports allocated.
files on gluster mount inaccessible.

I realize that this is a corner case, but is there some reason I can't have 
my quorum all on one host?

My setup: oVirt on Centos 6.5, updated yesterday.

RFE #1: an easy, positive way to find out if a volume is available. Currently 
the only way I know is to look at "volume info" to see if it is started, then 
at "volume status" to see if ports are assigned.

RFE #2: A way to designate that a volume would become read-only on lack of 
quorum, rather than taking it offline.  I am sure I am not the only one with 
an almost-WORM use case, where having the volume go read-only would allow 
operations could continue as normal, just no new content could be added.  In 
my use case I will be serving media files in real time.  Under the current 
setup, I am considering mounting a brick as a read-only source, because that 
would allow operation to continue when quorum is lost.

Ted Miller
Elkhart, IN, USA



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