Large email account

[David Lang]

On Mon, 20 Dec 2004, Prasanna Buddhika wrote:

> Date: Mon, 20 Dec 2004 16:14:17 -0800 (PST)
> From: Prasanna Buddhika <p_buddhika at yahoo.com>
> To: info-cyrus at lists.andrew.cmu.edu
> Subject: Large email account
> 
> Hi,
> I have win2000 server running exchange 2000 server.
> There are 2 large email accounts (700000 emails in a
> single account) which we don't want to delete. But I
> want to move these 2 accounts to Linux machine with
> cyrus-imap server. Migration went very well. Only
> problem is the speed. When the 2 mail accounts on the
> exchange server and when I use exchange method to
> access the account via Microsoft outlook client it
> won't take even 1 minute to show all the massages. But
> if I use cyrus-imap to retriew (sync) the email it
> takes 30 minutes. But after sync it's fast. Only
> problem is when ever I logged off the system and log
> back in to the system again I have to wait 30 minutes
> to access the mail. Can anyone have a good suggestion
> to speedup this apart from deleting emails.:)
> Thank you,
> Prasan

What filesystem did you use on the linux box?

the ext2/ext3 filesystems slow down significantly when you have large 
files or directories with large numbers of files in them, and you are 
definantly far beyone the point where they will slow down (around 10,000 
messages they start to slow down and ~15,000-20,000 they become very bad)

if you want to use ext2/ext3 you will need to reasearch and implement the 
htree filesystem extention and see how well it helps you. Otherwise try 
converting to XFS or Reiserfs (my personal prefrence is XFS, but test for 
yourself)

one way to tell that it's a server-side problem is to login to the server, 
cd to the directory for the mailbox and do a ls, you will be amazed at how 
long it will take to respond.

once you get the server working well then the next step is to get a better 
client then outlook as the other posts have pointed out, but if you were 
to switch to another client without fixing the server you would find that 
every action you take is very slow (now moving from outlook you may not 
notice quite how slow, as outlook is one of the slower clients to start 
with)

David Lang


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