On Wed, 29 Jun 2005, Michael Loftis wrote:
--On June 29, 2005 4:30:06 PM -0400 Joel Nimety <[EMAIL PROTECTED]>
wrote:
Hello,
I'm trying to set up cyrus-imap as a backend for an email archiving
solution. I'm creating one account on the imap server for each customer
domain(s) we'll be archiving mail for. I'm concerned that the number
of emails that will end up in each INBOX will reach some limit (ext3 fs
limit, practical limit, etc.)
With EXT3 there are definite limits, not hard ones, but practical ones for
time to traverse/read the inode and list. Use ReiserFS. For Mail clients
most can't handle big folders because many of them are just POP3/NNTP clients
retrofitted to squak IMAP. Get a real IMAP client like Mulberry that takes
advantage of server side sorting, threading, and searching to allow for
(nearly) limitless mailboxes but not download each and every header.
With ReiserFS and UFS+Hashdirs (Linux and FreeBSD respectively) I personally
have many mailboxes that are well over 20k or 30k messages, and have a few in
the 200k range, haven't run into any performance problems. With EXT3 I had
serious problems in the 5k range, or less.
In the interest of completeness, under 2.6 linux kernels you can format an
ext3 partition using the dir_index option. This enables a hash tree index
for directories that supposedly improves lookups with very large
directories. Here is the command I use to build my mail spool filesystem:
mkfs -t ext3 -j -m 1 -O dir_index /dev/sdb1
I have not used other filesystems such as Reiser or XFS, so I cannot offer
any performance comparisons.
Andy
---
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