On Tue, 2004-03-30 at 17:34, Suresh Ramasubramanian wrote: > [3/30/2004 5:17 PM] Manvendra Bhangui : > > > Personal order of preference > > qmail (it is the most beautiful piece of C programming I have ever seen) > > Also qmail code is just around 16000 lines, many times > > smaller than postfix. > > yup - but I tend to agree with a lot of what Matthias Andree has to say > - http://www-dt.e-technik.uni-dortmund.de/~ma/qmail-bugs.html >
Except for the point - qmail unbundles all mail, in the above document, all are non-issues which Mathias keeps on harping on the same point again and again and again. > > Sendmail is actually up for a rather complete rewrite, and is shedding a > lot of its old code baggage. You will find that sendmail is actually a > lot more secure than what the qmail.org site claims it to be (that > "comparison" would be based on really ancient sendmail versions like 8.8 > i guess) With a huge code, sendmail can never be secure http://www.iss.net/issEn/delivery/xforce/alertdetail.jsp?oid=21950 Just do a google search on sendmail vulnerability. You will keep on getting new vulnerabilities every now and then. > > process enormous amount of local mail delivery, qmail with the big-todo > > patch and a patch for 'silly qmail syndrome' does better than postfix (I > > Too many patches. > > > had to pull out postfix out of production on a server which did > > 600000 emails/day. The load on my box used to shoot > 100 with > > postfix running. With qmail however the load remained below 20. > > Interesting. We run a rather large freemail / messaging hosting service > with rather more mail volumes, but I have a few questions. > > > On a server doing largely remote deliveries I have not found much > > difference between qmail and postfix. > > * Was this outbound delivery, or inbound (MX) for your domain - most > likely inbound, from your statement This are our relay servers for corporates (on some we run postfix and some we run qmail). We wiped out sendmail from our servers 3 years back. > > * What server hardware / OS / filesystem > Sun E3500 with 6 CPU, Solaris 8, vxfs (1 terrabyte of disk space, and around 1.2 Million Users and around 27 million mails lying on the server). The reason I wanted to try postfix was because it did not unbundle mails (unlike qmail). I expected this would give me a big performance increase over qmail because quite a lot of mails coming to my system were to more than one user in the To, CC headers. However the smtpd process of postfix could not handle very high incoming rate during the peak hours (9:30 AM to 2:00 PM). I tried postfix for a month and gave up after plenty of user complaints. With the EXT-TODO extension to qmail, qmail would handle the high incoming rate easily. With very high svc_t and my disks always 100% blocked, it made a big difference running qmail. Though the IO did not improve, but at least the CPU came down drastically when using qmail. extended device statistics device r/s w/s kr/s kw/s wait actv svc_t %w %b ssd106 114.1 226.1 1614.0 868.0 0.9 26.2 79.9 10 100 ssd107 110.9 345.7 748.5 1085.2 51.4 64.0 252.7 100 100 With qmail, it is rare to see qmail processes in the top. My current top result last pid: 1327; load averages: 12.29, 10.26, 9.86 10:25:41 793 processes: 775 sleeping, 1 running, 12 zombie, 5 on cpu CPU states: 0.0% idle, 26.7% user, 43.6% kernel, 29.7% iowait, 0.0% swap Memory: 4096M real, 125M free, 840K swap in use, 2561M swap free PID USERNAME THR PRI NICE SIZE RES STATE TIME CPU COMMAND 18303 mysql 178 59 0 408M 283M cpu19 691:25 3.05% mysqld 296 root 1 0 0 2376K 1896K cpu19 0:01 0.66% top 941 supermail 1 42 0 1704K 1328K sleep 0:00 0.38% imapd 1235 supermail 1 0 0 1704K 1328K sleep 0:00 0.30% imapd 1291 supermail 1 20 0 1704K 1328K cpu14 0:00 0.26% imapd 1278 supermail 1 60 0 880K 768K sleep 0:00 0.23% pop3d 339 supermail 1 60 0 1712K 1336K sleep 0:00 0.22% imapd 29207 supermail 1 60 0 1712K 1336K sleep 0:00 0.21% imapd 446 supermail 1 58 0 1752K 1376K sleep 0:00 0.18% imapd 684 supermail 1 60 0 1752K 1376K sleep 0:00 0.18% imapd Another point to note that with postfix, I had a tough time with syslogd. Postfix uses syslog() function to log everything. And syslog is a performance PIG. with qmail you can use multilog http://cr.yp.to/daemontools.html After my experience with multilog, I encourage people to write all error messages to stderr. multilog takes care of rest. > * Were you running a local dns cache, or was the resolver running on > another box on the same switch? local dns cache ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ linux-india-help mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/linux-india-help
