[Dovecot] Re: dovecot Digest, Vol 26, Issue 5
dovecot-request@dovecot.org wrote:
Am Samstag, 4. Juni 2005 01:31 schrieb Han-Wen Nienhuys:
I'm seeing terrible performance. Sometimes, my client needs several>
(...)
How can I debug this problem? I'm running dovecot .99.14 on a Mac Mini (OS X 10.3, 512 mb, 80 gb).
mbox or maildir?
Maildir.
Listing or opening the directory via the OS is rather slow, btw,
maagd:~/Maildir/.sent$ time du 220240 ./cur 0 ./new 0 ./tmp 234776 .
real 1m35.207s user 0m0.060s sys 0m1.850s maagd:~/Maildir/.sent$
I'm using an Am486DX4-100 with 64 MB to serve my personal mail. (about 650 MB distributed over about 100 imap folders)
indeed, so 160 mb on a beefier machine shouldn't be a problem.
-- Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen
On Sat, 4 Jun 2005, Han-Wen Nienhuys wrote:
dovecot-request@dovecot.org wrote:
Am Samstag, 4. Juni 2005 01:31 schrieb Han-Wen Nienhuys:
I'm seeing terrible performance. Sometimes, my client needs several>
(...)
How can I debug this problem? I'm running dovecot .99.14 on a Mac Mini (OS X 10.3, 512 mb, 80 gb).
mbox or maildir?
Maildir.
Listing or opening the directory via the OS is rather slow, btw,
This is one of the problems that I've heard about with maildir. If you have a lot of messages in a folder, it may be slow. If listing (i.e., "ls -l") is slow, then maildir will likely be slow as well. maildir relies on the filesystem, so if it isn't good at dealing with a lot of files in a directory, maildir won't work well.
I'm using dovecot over NFS with mbox and it is usually very fast due to dovecots caching. This should work the same, regardless of mbox or maildir. mbox is generally slow with large (in size) mailboxes and NFS usually isn't as fast as local disk.
Have you tried a newer version? I use the latest from CVS and it seems pretty good. So far, I've seen no corruption that dovecot hasn't dealt with on its own. There's probably about 100 accounts using it and I'm almost ready to expand the test bed considerably. I'm sure the "stable" branch works fine and is easier to compile than the CVS one ;-) This way, you will be using the newer code base and any problems will be more likely to get fixed.
Todd
Todd Burroughs wrote:
How can I debug this problem? I'm running dovecot .99.14 on a Mac Mini
(OS X 10.3, 512 mb, 80 gb).
mbox or maildir?
Maildir.
Listing or opening the directory via the OS is rather slow, btw,
This is one of the problems that I've heard about with maildir. If you have a lot of messages in a folder, it may be slow. If listing (i.e., "ls -l") is slow, then maildir will likely be slow as well. maildir relies on the filesystem, so if it isn't good at dealing with a lot of files in a directory, maildir won't work well.
Have you tried a newer version? I use the latest from CVS and it seems pretty good. So far, I've seen no corruption that dovecot hasn't dealt
I think I've got the problem diagnosed to be outside of dovecot. I've posted to Apple's board,
http://discussions.info.apple.com/webx?50@852.bHHyawkY1ge.0@.68b15954
The trouble is that it's only slow on that volume, while a USB harddisk is much faster. Also, I have no clue how I can dig into MacOS for further diagnosis.
Hi,
I hope I'm in the right place. I'm running the dovecot 0.99.14 imap server on my mac mini (10.3), and see abysmal performance. I suspect that it is due to some directory listing problem with the root volume, which holds my IMAP Mail repository (maildir format).
maagd:~/Maildir$ time du .sent/ (..) real 1m13.127s user 0m0.050s sys 0m1.590s
If I try the same with a similar HD (40gb, 2.5", 4200 rpm, HFS+ journaled) mounted over USB2, I get nearly instantaneous performance.
maagd:~$ time du /Volumes/Naamloos\ 1/test/.sent/ 220240 /Volumes/Naamloos 1/test/.sent//cur 8 /Volumes/Naamloos 1/test/.sent//new 0 /Volumes/Naamloos 1/test/.sent//tmp 234784 /Volumes/Naamloos 1/test/.sent/
real 0m3.492s user 0m0.080s sys 0m0.980s
maagd:~$ mount /dev/disk0s3 on / (local, journaled) /dev/disk1s3 on /Volumes/Naamloos 1 (local, nodev, nosuid, journaled)
Any tips how can I further diagnose this problem?
thanks!
-- Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen
Am Samstag, 4. Juni 2005 14:36 schrieb Todd Burroughs:
Maildir. Listing or opening the directory via the OS is rather slow, btw,
This is one of the problems that I've heard about with maildir. If you have a lot of messages in a folder, it may be slow. If listing (i.e., "ls -l") is slow, then maildir will likely be slow as well. maildir
AFAIK ls also sorts the messages by default.
It's correct however that you should use a file system which can cope with many tiny files per directory. My "imap server" uses the journalling Reiser FS 3.5 filesystem which utilizes tree structures to allow fast access to single files in full directories and it seems to perform fairly well. Additionally I disabled the "atime" mount option to further reduce write operations.
I don't know how this translates to MacOS X however...
Greetings,
Gunter
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participants (3)
-
Gunter Ohrner
-
Han-Wen Nienhuys
-
Todd Burroughs