There is a problem with Postfix (2.2.8; 2.3-20060112) and Cyrus IMAP (2.3.1) (installed from ports) With Postfix on FreeBSD 6.0, transferring of messages using SMTP is slow, aproximately 7MB in 20 seconds on direct 100MBit/s link. In Cyrus IMAP there is a issue with message writing to IMAP folders. Reading of 8MB message takes a bit less than a second, but in that time 8MB message write to IMAP folder over 100Mbit/s connection takes ~7 seconds. If writing many small messages to imap folder (~1KB in size) then average transfer rate of them is ~10 messages per second. Hardware: (2x 3GHx Xeon, 2GB RAM, Adaptec 2410SA, 2x WD RAPTOR 74GB, 2x SEAGATE 300GB, Mainboard - Intel SE7520BD2) For example, there is no such problems with FTP. Fix: "sysctl -w net.inet.tcp.delayed_ack=0" fixes mentioned problems with data transfer
Responsible Changed From-To: freebsd-bugs->net Over to maintainers.
Probably it is interact between delayed ack and Nagle's algorithm. They shouldn't be used together: http://developers.slashdot.org/comments.pl?sid=174457&cid=14515105 So application which may be affected by this problem should disable Nagle's algorithm for via socket option TCP_NODELAY. As I can see current postfix uses setsockopt TCP_NODELAY so consider to upgrade postfix to 2.4.7 or 2.5.1 first. Postifx 2.2.8 is too old. -- WBR, Anton Yuzhaninov
Responsible Changed From-To: net->freebsd-net Canonicalize assignment.
State Changed From-To: open->feedback Dear Juris: I was wondering if you had received Anton's follow-up regarding Postfix and TCP_NODELAY, in particular, whether upgrading Postfix versions had resolved the problem for you. Thanks, Robert