[Gluster-users] question re. current state of art/practice

[Miles Fidelman]

[pardon if a duplicate - doesn't seem to have gone through the first 
time, earlier today]

Hi Folks,

We've been running a 2-node, high-availability cluster - basically xen
w/ pacemaker and DRBD for replicating disks.  We recently purchased 2
additional,  servers, and I'm thinking about combining all 4 machines
into a 4-node cluster - which takes us out of DRBD space and requires
some other kind of filesystem replication.

Gluster, Ceph, Sheepdog, and XtreemFS seem to keep coming up as things
that might work, but... Sheepdog is too tied to KVM, XtreemFS and Ceph
are still experimental.  Gluster seems to stand out as mature and well
supported (particularly with the RedHat acquisition), and seems to have
matured a lot since we last looked.

For a number of reasons (mostly rack space limits and cost) we have 4 1U
machines - with 4 drives in each - no real opportunity to separate
storage from processing.  The machines each have 4 GigE ports - we're
using 2 for external connections, and reserving 2 for server-to-server
communication.

All of which leads to several questions:

i.  Is it now reasonable to consider running Gluster and Xen on the same
boxes, without hitting too much of a performance penalty?

ii. Anybody out there running a small cluster along these lines?

iii. Any particular suggestions, caveats, guidance, pointers to
documentation, .... (particularly for a Debian environment, though it
wouldn't be that hard to migrate our Dom0s.

iv. Any thoughts re. phase-in and migration - i.e. how to get from 2
production nodes running Xen,DRBD,Pacemaker to 4 nodes running
Gluster/Xen/<pacemaker or some other failover capability>?

Or are we barking up the wrong tree entirely?

Thanks very much,

Miles Fidelman


-- 
In theory, there is no difference between theory and practice.
In practice, there is.   .... Yogi Berra