Email: <joseph.koshy AT SPAMFREE gmail DOT com>
This page contains a grab-bag of various performance-related tweaks for FreeBSD. Once I collect enough material I'll write up something along the lines of a proper article.
If your machines are on a fast, local (i.e., low-latency) network and large amounts of buffering need not indicate a high latency, try sysctl -w net.inet.tcp.inflight.enable=0 (this is now default in -current for local links).
Setting "sysctl -w net.inet.tcp.delayed_ack=0" speeds up Cyrus IMAP and Postfix. Link.
If you're using UFS and have large directories, increasing the value of the vfs.ufs.dirhash_maxmem sysctl can deliver dramatic performace improvements by allowing UFS to cache the directory in kernel memory. The default value is 2097152 (i.e., 2MB), and the vfs.ufs.dirhash_mem sysctl shows how much is currently being used.
- If you're using 7.0-RELEASE, try running with ULE scheduler
Tuning FreeBSD for different applications, by Avleen Vig.