First I have to apollogize that this posting is not 100% XMail related. Having said that, my problem is as follows:
We run XMail v1.9 on an Intel PIII 900MHz with 256MB RAM, using Slackware Linux 8.0 Kernel 2.4.9 for about half a year now with one domain and about 70 users. Traffic is about 30 MB of mail per day (sorry, since I do no logging I have no Idea of messages per day) ranging from 15 to 70 MB/day. So what's the problem ? Simply performance. But not allways. For months the system worked _very_ fine, responses where fast and transfer rate only limited by the connection's bandwith. And then, slowly the throughput eroded, sometimes coming to a grinding halt. Well what happens ? If users try to download mails, their client starts loading messages at a _realy_ low speed (a minute or two for some plain text message containing 20 lines pf text or so) and eventually times out. At the same time the load at the XMail box is about 0.01 and there is no network congestion as far as I can see. If they try half an hour later, everything is fine, or not, you never can tell. I tried to push data across the router in front of the mailserver by copying a large file via scp from my destop PC to the mailserver: transfer rate was close to the theoretical maximum of the network segments used (10 MBit Ethernet hub between the router and the mailserver) and system load at the router (also Linux but a Pentium MMX 233) was about 0.25. So, the machines and the network are capable of far more than I need, where could the bottleneck hide ? Last Friday I found estematedly 30 frozen messages, which I deleted after a very brief review (they all suffered misstyped domain or usernames) and users reported an improved situation on monday. But today there are just 3 frozen messages and we are back at snail mail again ;-) Does anybody of you have any bright idea what to do about this situation ? I can supply some further observations: * System uptime is 120 days now (but that usually is no problem in the UN*X world and I never saw Linux boxes suffering from long uptimes, unlike ... no, I will not start a new flame on that ;-) ....). * Sometimes, when I dig around in the system via ssh from the company lan (so only the router between me and the mailserver) I can watch the characters I just typed in appear on the screen one after the other, quite slowly (again something I am NOT used to) * I use my own perl virus filter script together with ClamAV - so sometimes, when some stupid sends a 5MB attachment to all users (about 70) the system gets quite busy. System load 16 (!) for an hour, scanning the same file 70 times, simultaneously. But it keeps responsive all the time ... slowly, but you still can mail and work on the box (great, those UN*X systems, aren't they ?) ... by the way, this is definitely NOT the problem I described above, because it only happens every now and then (users are not that silly ;-) ) * I watched with 'netstat -cteo' ... I see two to six simultaneous connections at best ... when someone has the 'timeout problem' the 'Send-Q' column in the output of netstat goes up to about 15000 which looks quite normal, compared to my scp-performance tests. * DNS works great ! All client connections resolve within a moment's notice, local as well as remote. I am quite puzzled. Any help _very_ welcome ! Goesta -- Let's stand together against 'Palladium' ... Link arms, don't make them http://online.securityfocus.com/columnists/96 - To unsubscribe from this list: send the line "unsubscribe xmail" in the body of a message to [EMAIL PROTECTED] For general help: send the line "help" in the body of a message to [EMAIL PROTECTED]
