[Dovecot] Dovecot servers / SAN
Hey guys, Wondering if anyone out there has any input on running Dovecot with SAN storage. Its coming to the time where we need to run load balanced servers, and past experiences steer us away from a NAS. Tips / pitfalls ?
Regards
Dean Manners
On Mon, Jun 19, 2006 at 09:43:26PM +1000, Dean Manners wrote:
Hey guys, Wondering if anyone out there has any input on running Dovecot with SAN storage. Its coming to the time where we need to run load balanced servers, and past experiences steer us away from a NAS. Tips / pitfalls ?
It probably depends more on the filesystem you're going to pave over your SAN. I had a test setup with three nodes over GFS (which from dovecot's POV is simply a local POSIX compliant fs) for a couple of weeks and it worked fine. But for other reasons it never went into production, it was only stressed under lab conditions.
Axel.Thimm at ATrpms.net
On 6/19/06, Axel Thimm <Axel.Thimm@atrpms.net> wrote:
On Mon, Jun 19, 2006 at 09:43:26PM +1000, Dean Manners wrote:
Hey guys, Wondering if anyone out there has any input on running Dovecot with SAN storage. Its coming to the time where we need to run load balanced servers, and past experiences steer us away from a NAS. Tips / pitfalls ?
It probably depends more on the filesystem you're going to pave over your SAN. I had a test setup with three nodes over GFS (which from dovecot's POV is simply a local POSIX compliant fs) for a couple of weeks and it worked fine. But for other reasons it never went into production, it was only stressed under lab conditions.
We ran it with a Lustre backend recently for test purposes. Though the solution worked well, didn't make sense given Lustre's design.
Axel: why did you move away from GFS? Any particular reason?
Regards,
Mustafa A. Hashmi mahashmi@gmail.com mh@stderr.net
On Tue, Jun 20, 2006 at 11:56:04AM +0500, Mustafa A. Hashmi wrote:
On 6/19/06, Axel Thimm <Axel.Thimm@atrpms.net> wrote:
On Mon, Jun 19, 2006 at 09:43:26PM +1000, Dean Manners wrote:
Hey guys, Wondering if anyone out there has any input on running Dovecot with SAN storage. Its coming to the time where we need to run load balanced servers, and past experiences steer us away from a NAS. Tips / pitfalls ?
It probably depends more on the filesystem you're going to pave over your SAN. I had a test setup with three nodes over GFS (which from dovecot's POV is simply a local POSIX compliant fs) for a couple of weeks and it worked fine. But for other reasons it never went into production, it was only stressed under lab conditions.
We ran it with a Lustre backend recently for test purposes. Though the solution worked well, didn't make sense given Lustre's design.
Axel: why did you move away from GFS? Any particular reason?
The customer I was working for was an early adopter of GFS 6.1 (aka GFS on 2.6) in the hopes that Debian would pick it up, since Debian is the Linux distribution he is running.
When it became apparent that this would not happen within the project's time constraints he had to choose between a cluttered server os landscape vs non having active-active cluster filesystem setups and due to staff constraints chose to freeze the GFS project altogether. That wasn't dovecot or in general mail related.
So unless you face the same constraints, e.g. run a distribution w/o a cluster file system and would have to do it yourself from scratch, going GFS (or OCFS2) is a good idea for dovecot (and exim which was the MTA choice).
I would recommend RHEL4/GFS/dovecot/exim (+ spamassassin/clamav and friends) for a nice scalable cluster solution. In fact the customer's and ATrpms' mail setup is the one I created for the GFS cluster, it now just has one active node (the customer for the reasons above and ATrpms due to not having a SAN :).
Axel.Thimm at ATrpms.net
On 6/20/06, Axel Thimm <Axel.Thimm@atrpms.net> wrote:
Axel: why did you move away from GFS? Any particular reason?
The customer I was working for was an early adopter of GFS 6.1 (aka GFS on 2.6) in the hopes that Debian would pick it up, since Debian is the Linux distribution he is running.
When it became apparent that this would not happen within the project's time constraints he had to choose between a cluttered server os landscape vs non having active-active cluster filesystem setups and due to staff constraints chose to freeze the GFS project altogether. That wasn't dovecot or in general mail related.
So unless you face the same constraints, e.g. run a distribution w/o a cluster file system and would have to do it yourself from scratch, going GFS (or OCFS2) is a good idea for dovecot (and exim which was the MTA choice).
I would recommend RHEL4/GFS/dovecot/exim (+ spamassassin/clamav and friends) for a nice scalable cluster solution. In fact the customer's and ATrpms' mail setup is the one I created for the GFS cluster, it now just has one active node (the customer for the reasons above and ATrpms due to not having a SAN :).
Thanks for the detailed reply. I am looking at NFS given Lustre's design and the fact that we have to run with Debian as well. I still don't see GFS in debian stable -- may try a source build (having taken a similar route with Lustre).
Regards,
Mustafa A. Hashmi mahashmi@gmail.com mh@stderr.net
participants (3)
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Axel Thimm
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Dean Manners
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Mustafa A. Hashmi