[EMAIL PROTECTED]> <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <[EMAIL PROTECTED]> X-Operating-System: Linux zeroth 2.4.18 X-PGP-Key-URL: http://zeroth.crossbar.net/~bartdu/gpg.pubkey.asc X-PGP-Key: 07F114B4 User-Agent: Mutt/1.5.4i
Paul, i do find an average of 800kb/mailbox relatively small, we have an average of 3,6mb/mailbox. obviously making a temp copy of an mbox file every time a user pops would cause a lot of disk I/O, in our case (60*3,6mb)/sec copied to a temp location and that's exactly why i think maildir is not being a slow down in our case. and we're using Sendmail.. (expecting a lot of comments now :) bart On Fri, Jan 23, 2004 at 10:15:20AM +1100, Paul wrote: > > Hi Bart, > > Average size of our mailboxes is around 800kb per mailbox. of the 297,000 > about 250,000 of them are active and live. 50,000 of them are > inactive/suspended holding up 55GB between them. > Our total spool is currently 240GB including the 55GB for the > suspend/inactive users. We just haven't deleted their old spool data yet. > What do you use for your SMTP server? > > ----- Original Message ----- > From: "Bart Dumon" <[EMAIL PROTECTED]> > To: "Paul" <[EMAIL PROTECTED]> > Cc: "Subscribers of Qpopper" <[EMAIL PROTECTED]> > Sent: Thursday, January 22, 2004 9:58 PM > Subject: Re: qpopper high load average > > > > Hi Paul, > > > > We have 320k mailboxes, 4 dual xeon mailservers. the setup was > > highly influenced by the requirement of redundancy, therefor we're > > using multiple machines with a spool on NFS. at least 2 boxes > > should be able to handle all the traffic, so i'm quite certain > > there is an underlying problem which affects our performance. > > > > The NFS connection is 100mbit FD for each box, the NAS itself > > is 1Gbit FD. during business hours one box can easily get > > to 30-40mbit/sec. resulting in 100-120mbit/sec of throughput > > on the NAS. > > You're considering maildir/nfs to be a potential slow down, > > but i don't see it that way because disk I/O is usually the > > bottleneck on smtp/pop servers. both ways have their advantages > > and disadvantages. > > > > Anyway, you seem to be doing pretty well with your single system, > > but do you have any idea of the average size of the mailboxes > > on your system and the percentage of active users? > > > > > > bart > > > > On Thu, Jan 22, 2004 at 10:51:39AM +1100, Paul wrote: > > > HI Bart, > > > > > > We run a mailserver for a 297,000 odd mailboxes. We normally during peak > see > > > a load average of about 15, this is sustained and doesn't flucate that > much. > > > The box is a dual 3.06ghz xeon with 3gb of DDR and 525GB of Ultra320 > raid5 > > > which is used for spool. On the server we have qpopper auth'ing via > mysql > > > and exim as the local smtp server. > > > Our mail is stored in a double hash array like > /var/spool/mail/e/b/ebadine > > > and we just use flatfile, instead of Maildir. The riad should be raid10 > but > > > it's not always realistic, we use raid5 for example, its a bit of slow > down > > > compared to raid10 but meets our needs > > > > > > Maildir would be a potential slow down, especially over NFS. What speed > > > Mb/sec do you get over the NFS connection? I'm assuming its 100mbit full > > > duplex > > > When we originally had everyone in /var/spool/mail/$username our system > > > bogged down to an insane level, once we double hashed it, it was > fantasic. > > > > > > Do run any form of performance monitoring on the server? We use mrtg and > > > graph cpu, network, memory etc so we can easily spot bottlenecks. > > > > > > ----- Original Message ----- > > > From: "Bart Dumon" <[EMAIL PROTECTED]> > > > To: "Paul" <[EMAIL PROTECTED]> > > > Cc: "Subscribers of Qpopper" <[EMAIL PROTECTED]> > > > Sent: Thursday, January 22, 2004 8:41 AM > > > Subject: Re: qpopper high load average > > > > > > > > > > > > > > On Wed, Jan 21, 2004 at 11:24:12AM +1100, Paul wrote: > > > > > How many connections/sec for the server during peak? What does the > load > > > avg > > > > > get to? What storage is it (the mail spool)? What filesystem? > > > > > > > > during peaks we get about 15 connections/sec per server, the load > > > > gets up to 800 if we do not interfere. once the popper gets > > > > restarted the load will decrease. the mail spool is kept on a NAS > > > > and is accessed using nfs. > > > > > > > > > > > > bart
