Am 27.10.2012 13:58, schrieb Bernics Gábor | Penta Unió Zrt.:

Thank you

I use dovecot LDA (+sieve) with maildir.

conf:

in general you should upgrade to 2.1.x with lmtp

for better performance use

auth cache

http://wiki.dovecot.org/Authentication/Caching an example you find in your config

http://pastebin.com/9fhYD58g

logs:

http://pastebin.com/CXct3B6k

i dont see imap here, do more verbose logging

connections:

http://pastebin.com/v24iRz60

to much info for this stage

how much traffic concurent in fail stage would be interesting

any chance measure iops of the storage ?

what mail client ?

if tb

do debug

http://wiki.dovecot.org/Debugging/Thunderbird

how much mail does this mailbox have

"It's intresting when I open an another old mail (with 0 sec wait), after new mail open quickly.

may client cached"

it's possible.

2012-10-27 11:36 időpontban Robert Schetterer ezt írta:

...

Am 27.10.2012 09:52, schrieb Bernics Gábor | Penta Unió Zrt.:

...

Hello, I have a dovecot IMAP server (relative small hardware: HP Microserver with 6 Gbyte RAM, linux soft RAID1 with 2x 7200 SATA disk) with 100 Gbyte maildirs.

that seems ok

...

Server works fine but sometimes I can open mails slowly (5-10 sec), typical with new mails.

what mailbox type, how much mail in that mailbox how many concurent cons, imap or pop3 ? Is it dovecot mail indexes or I/O problem?

perhaps this , perhaps other

Best Regards MfG Robert Schetterer

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Thanks a lot to everybody

First step I will upgrade to dovecot2.

I will write my experiences.

"Running with fsync disabled is like having sex with a Bangkok prostitute without a condom while juggling chainsaws while driving drunk at 250kph at night without headlights."

:-)

Gabor

2012-10-27 20:27 időpontban Stan Hoeppner ezt írta:

On 10/27/2012 6:58 AM, Bernics Gábor | Penta Unió Zrt. wrote:

...

I

use dovecot LDA (+sieve) with maildir. conf: http://pastebin.com/9fhYD58g [1]

Next time simply paste "dovecot

-n" output into your email.

Assuming Dovecot is the only program

accessing the maildirs, try:

maildir_very_dirty_syncs=yes

That

may help some.

It may not have been a factor in this case, but note

doing a full text search on a large mailbox on

maildir you will see latency, and it is unavoidable. Neither a single 7.2K SATA spindle nor md/RAID1 pair of

service all the sector requests in a timely fashion.

Also, I noticed you disabled fsync. This is a very very bad idea for a mail server. If you lose power, or suffer a kernel/hardware/etc crash, you lose the Linux buffer cache contents. Thus, you may lose emails that haven't been flushed to disk, and

that when anyone is this hardware with them, has enough seek capacity to possibly get index file

corruption if mmap'd pages haven't been flushed.

Running with fsync disabled is like having sex with a Bangkok prostitute without a condom while juggling chainsaws while driving drunk at 250kph at night without headlights.

fsync does hurt write performance to a degree, especially with maildir storage, but will likely be invisible on a small server with few users/light load. And it will prevent potentially severe problems with file corruption and/or lost emails.

Links:

[1] http://pastebin.com/9fhYD58g