[Dovecot] IMAP quotas - Reasonable size?
Hello...
I'm setting up dovecot (IMAP only) at an ad-agency (Lots of big files attached to mails). I'm wondering... What would you consider to be reasonable mail quota? My concern is, that some client-software will have problems with huge mailboxes. I was going to give everyone 2GB, but some users demand 15GB+. Does dovecot "prefer" mailboxes within a certain size?
Looking forward to hear your thoughts on the subject.
Thanks, Tobias Balle-Petersen
I tend to think that it highly depends on the filesystem/IO scheduler etc, at least with maildir.
I'm using maildir on ext3 (with dirhashing) on a Xen instance (so I/O is terribly slow) and the limit up to which I can tolerate the wait seems to be at about 30-40k mails in a single folder irregardless of mail size. You can probably improve on that with XFS (directory listings are cached in memory rather than re-read every time) and by having a dedicated server, which I assume you do.
So if you have 30k 10MB emails you're already at almost 300 GiB :)
FWIW, my Inbox currently has about 16k mails with 276MiB size, but I'm fairly sure you can fare just as well with larger mails.
johannes
On Tue, 2008-02-05 at 10:01 +0100, Tobias Balle-Petersen wrote:
As Johannes said, the mailbox size doesn't really matter to Dovecot, only the number of messages (except for operations such as server-side search). It's also possible to specify a message number quota, but since users can have multiple mailboxes it's less of a problem if users have ten 10k message mailboxes than one 100k message mailbox.
Anyway, Dovecot should be able to handle tens of thousands of messages in a single mailbox easily. I've been testing it with a 350k message mailbox once in a while. With ext3 it takes maybe 20 seconds to initially read the directory into cache, and after that for each sync (new message, flag change, expunge, etc) it takes about 2 seconds to sync. v1.1's dbox format doesn't need this syncing and all operations are pretty much instant.
I don't know about clients though.
participants (3)
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Johannes Berg
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Timo Sirainen
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Tobias Balle-Petersen