Recomendations for a 15000 Cyrus Mailboxes

[Greg A. Woods]

At Tue, 10 Apr 2007 06:56:43 -0500, Nestor A. Diaz wrote:
Subject: Recomendations for a 15000 Cyrus  Mailboxes
> 
> These are the plans: (comments on every number will be apreciated)
> 
>    1. Linux LVM over a 600 GB RAID 10 ( 4 x 300 GB)

I would only ever be able to recommend NetBSD or FreeBSD, and I would
strongly recommend some form of external RAID controller, either SCSI or
Fibre Channel attached.

>    2. Which filesystem seems to be the better ? ext3 ? xfs ? reiserfs ?

FFS, or maybe FFSv2  :-)

>    3. Which options to format the filesystem ? acording to the chosed
>       filesystem

2K fragments on FFS would be OK.

>    4. Which pop3 / imap proxy to use ?

Proxy?  What for?

>    5. Single instance or multiple instances of cyrus ? taking in mind
>       that there should be the option to recover a mailbox or some mail
>       of a mailbox without having to shut down the whole cyrus system.

Single instance for Cyrus, but with a separate MX host that can be
(quickly and easily) replicated and which does delivery via LMTP/TCP.
That's far too small a system to justify the complexity of having to
manage multiple systems.

Recovery of an individual mailbox can usually be done safely without
shutdown I think, though it might be good to be able to pause delivery
for that specific mailbox, and of course make sure the user isn't signed
on to access it either.  I'm not sure how to pause delivery for an
individual mailbox with Postfix, but one idea would be to simply have
the MX host return a temporary SMTP error (e.g. 451), and make sure
there's nothing for that mailbox in the incoming queue either.

>    6. Best way to perform backups ? LVM snapshots ? shutting down some
>       cyrus partitions ? RAID10 hot swap ?

If you use FFSv2 snapshots then you'd probably be OK doing an rsync of
the snapsot to another (preferably off-site) backup host.  Perhaps you
would want to use rdiff-backup, though a plain rsync should be
sufficient for mailboxes.

-- 
						Greg A. Woods

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