> On Mon, Jan 29, 2007 at 04:14:33PM -0800, Tom Samplonius wrote: >> >> ----- "Simon Matter" <simon.matter@xxxxxxxxx> wrote: >> > >> > Believe it or not, it works and has been confirmed by several peoples >> on >> > the list using different shared filesystems (VeritasFS and Tru64 comes >> to >> > mind). In one thing you are right, it doesn't work with BerkeleyDB. >> > Just switch all your BDB's to skiplist and it works. This has really >> been >> > discussed on the list again and again and isn't it nice to know that >> > clustering cyrus that way works? >> >> Yes, useful. But the original poster wanted to combine Cyrus >> application replication with a cluster filesystem (GFS >> specifically). It seems pretty unusual to combine both. GFS has a >> lot of locking overhead of writing, and e-mail storage is pretty >> write intensive. And Cyrus replication can have its own performance >> issues (slow replication that never catches up). Why do both at the >> same time? > > The reason to use a clustering FS: if it works, it is very simple. Each > node can be more or less identical. And, therefore, more or less > redundant. And the system is scalable (just add a node), to the point > where the GFS locking overhead begins to be the bottleneck. And HA is > simple: if you want to do maintenance a node, just get it offline - > nobody'll notice. > > The reason to use replication: The "master" cluster has but one > filesystem. Of course it's on a SAN, RAID, blah. But if the SAN fails - > such a thing happened a couple years ago, even SANs fail - we lose all > mail received since last backup. Not nice. (But if combining these two > really result in severe performance losses, we might have to > reconsider.) > >> And GFS 6.1 (current version) has some issues with large directories: >> >> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=214239 > > This might be a problem, since we have some users that really have 10000 > messages in their INBOX. Although it seems that Cyrus itself cannot cope > with this either... in our current, non-clustering setup. But then, it's > an old version. Interesting, I have some folders with ~100'000 messages and cyrus handles it very nice. Did you say you have a problem with 10'000 messages in a mailbox? Simon ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
