----- Original Message ----
> From: Daniel V. Reinhardt <crypto...@yahoo.com>
> To: postfix-users@postfix.org
> Sent: Mon, June 28, 2010 3:32:04 AM
> Subject: Re: performance tuning - relay
>
>
----- Original Message ----
> From: Stan Hoeppner <
> ymailto="mailto:s...@hardwarefreak.com";
> href="mailto:s...@hardwarefreak.com";>s...@hardwarefreak.com>
> To:
>
> href="mailto:postfix-users@postfix.org";>postfix-users@postfix.org
>
> Sent: Mon, June 28, 2010 2:23:15 AM
> Subject: Re: performance tuning -
> relay
>
> Christian Purnomo put forth on 6/27/2010 5:50
> PM:
> From your
> questions above, I could see where you're
> coming from that if
> Server2
> has performance problem then it
> would make sense to see the
> queue built
> up at Server1. I
> can confirm server2 is very underload at
> any
> time, the server
> is overspec'ed for what it is intended to do. I
>
> can also
> confirm while those thousands of emails queued up at Server1,
>
>
> Server2 was running smooth with 0.1-0.3 load average.
What
>
> piqued my curiosity is why the queue on server2 starting growing,
> and
rather
> large at that, _after_ you got the Postfix bottleneck
> straightened out
on
> server1.
> We have had server2 for
> about 4 years now and we have been
> having this
> issues in the
> last 1 year where one of our new server
> happens to be a
>
> mailling list which sends out thousands of emails to
>
> subscribers.
>
> Anyway, Server2 spec is HP DL385G4, 4G RAM, 6 SCSI
>
> disks RAID 5 and
> reiserfs.
I would have thought
> this
> hardware would be able to get the mails into the
mailboxen as
> quickly as
> server1 could push them over, without the queue
building
> up as you
> demonstrated in a previous message. Email service
> is
primarily a disk
> bound application. IIRC, with the DL385G4
> you would have the
Smart
> Array 6i which is an integrated entry level
> controller. Even so,
> with
128MB of read/write cache and
> 6x10k(15?)rpm drives on a SCSI 320 bus,
> even in
a slowish RAID5
> configuration, you should easily be able to sync to
> mailboxen
as
> many messages as server1 could push over either fast or gigabit
>
> ethernet.
This server should be able to sync a few hundred emails to disk per
>
> second.
Is the 6i just really horrible at RAID5, or is there
> something in the
> software
stack slowing things down? Were you
> peaking the disk subsystem
> when the queue
was building?
>
> The delivery method on Server2 is
> maildrop - we use some mailfilter
> rule
> to drop certain emails to certain
> folders. I can
> understand this is
> adding some overhead for the
> local delivery
> on Server2 but this is the
> cost I'm happy to take
> on. The
> queue can build up on Server2 and clear
> up overtime
> without
> impacting our primary MX (Server1).
I'm not familiar at all with
>
> maildrop as I've never used it. That said, I
wouldn't think maildrop
>
> alone would cause such a bottleneck. Some versions of
Reiser
> are known
> for great speed will lots of small files, at least as far
> as
delete
> performance. However, most versions of Reiser do not
> do so well
> with
large files. Reiser is normally a good
> performer with maildir, but
> doesn't do
so well with mbox, especially
> once the mbox files get
> large.
Other disk writes? Is
> maildrop or any other process you're
> running creating
extra log
> stamps per email processed? I assume you're
> storing the OS,
> logs,
mail, everything on that RAID5 volume. Is this
>
> correct?
As you stated, you're not really concerned with queue growth on
>
> server2. I
went through all this simply because I think you're
> leaving
> some performance,
maybe quite a bit, on the table WRT
> server2. I'm
> guessing it's in the
OS/software stack and not
> the hardware. You may be
> able to get this box
screaming with
> simple changes (reduce logging to only
> what's necessary), and
maybe
> one or two more major changes (maildir to mbox
> or vice versa,
> switching
from Reiser--defunct now anyway--to XFS). Or a
>
> really big change, dumping
Maildrop/Courier for Dovecot/LDA which is quite a
>
> bit quicker from everything
I've read. I say read because I've
> not used
> Courier but I have used Dovecot,
and still do.
Sorry
> if I've wasted
> your time here. I just thought I'd point out a
> few
things just in case
> you get the urge to poke around on server2
> looking for a
little performance
> boost.
--
>
Stan
-----------------
Stan,
Actually you do not need
> to pay for their mail forwarding services. I have a sever setup to accept
> email just fine and dandy for a dyndns.org support host, and I do not pay
> anything for it. I get mail to my system woa.homeip.net just fine without
> paying.
The paid for services you speak of are for people who want
> to customize their own dyndns settings.
You can send me an email to
> ymailto="mailto:crypto...@woa.homeip.net";
> href="mailto:crypto...@woa.homeip.net";>crypto...@woa.homeip.net and I will
> receive it, and I can send out. I would suggest you get a dyndns.org
> account, and do some research on it.
I have been using dyndns.org since
> about 2001 when I first my DSL Connection.
Daniel
> Reinhardt
Website: www.cryptodan.com
Email:
> ymailto="mailto:crypto...@yahoo.com";
> href="mailto:crypto...@yahoo.com";>crypto...@yahoo.com
>
Please disregard my reply to this message thread. I was going to reply to
another thread, but had this one highlighted. Sorry for butting in.
Daniel Reinhardt
Website: www.cryptodan.com
Email:
crypto...@yahoo.com
