On 13/01/11 09:58, Stan Hoeppner wrote:
Jonathan Tripathy put forth on 1/12/2011 8:58 AM:
Major point is that GlusterFS is NOT another file system. GlusterFS uses a
disk based backend and relies heavily on the underlying filesystem extended
attributes for handling which file is more recent on one brick over another
when performing a self heal after a split brain condition.
Maybe this isn't really too much of an issue in mail delivery, as find aren’t
usually modified, are they?
I may split up the servers though to reduce split brain. As if one glusterfs
server goes down, no mail server would be able to access it
GlusterFS is a distributed filesystem, not a clustered filesystem. There is a
huge difference WRT acceptable uses. Distributed filesystems are fine for
massive storage needs of relatively static files, not for serious transaction
oriented workloads. Cluster filesystems are much more suited to the latter, and
will handle the former without issue.
Likely, the best solution for the OP, from both a performance and simplicity of
management standpoint, is neither of these, but NFS, either a _good quality_ NFS
appliance such as a NetApp et al, or if that price is too steep, a purpose built
Linux server with kernel mode NFS server.
Well I should update this post. Reading around, I've given up on the
idea of GlusterFS as performance isn't great when using it.
While Postfix works well with NFS, Dovecot has some serious issues with
it (according to their wiki and mailing list).
What does everyone think of a DRBD + GFS2 idea?
If you actually run an environment where total redundancy is a requirement, then
you'd already know all of these things and not be asking here. Thus, you're a
small environment but you _think_ you need an exotic fail safe architecture like
a big environment, which very few sites actually _NEED_ including some of the
big ones.
Ask Wietse about the architecture of the HA Postfix cluster that serves list
mailing list. Then ask him how much downtime the list has experienced in the
last 5 years due to host or storage problems (vs network). The answers may
likely be both surprising and informative.
Yes, I appreciate this. But free software costs nothing, so no real harm
in at least trying. Even if it doesn't work out in the end, at least I
will have learnt :)
Don't worry, there will be a very good backup strategy behind all this...
