LARGE single-system Cyrus installs?

[Robert Banz]

>
> One of the things Rob Banz recently did here was to move the data/
> config/proc directory from a "real" fs to tmpfs. This reduces the
> disk IO from Cyrus process creation/management.
>
> So the way we do stuff here is that each Cyrus backend has its own
> ZFS pool. That zpool is divided up into four file systems:
>
> /ms1/data
> /ms1/mail
> /ms1/meta
> /ms1/sieve
>

Just a side note on the partition lay-out - originally I was thinking  
of having the 'meta' partition be all of the databases/index files.   
Figured it'd be nice to be able to tune that zfs fs with a different  
recordsize if necessary.  However, I changed my mind, and our "meta"  
partition only contains the squat index files.

Why?  We're doing our backups via ZFS snapshots -- and while we DO  
want to snapshot the various meta-files, we're not too interested in  
saving all the squat indexes.

It seems to be working pretty well, and having a 7-day backlog of the  
data/mail/sieve directories has come in quite handy in recovering  
from stupid user tricks, such as wiping our their sieve rules, or  
folder deletes.*

* haven't added the delayed-folder-delete patch yet ;)

-rob