from the pg doc: http://www.postgresql.org/docs/devel/static/wal-reliability.html :On Linux, IDE drives can be queried using hdparm -I; write caching is enabled if there is a * next to Write cache. hdparm -W 0 can be used to turn off write caching. SCSI drives can be queried using sdparm<http://sg.danny.cz/sg/sdparm.html>. Use sdparm --get=WCE to check whether the write cache is enabled and sdparm --clear=WCE to disable it.
from the hdparm man page : http://linux.die.net/man/8/hdparm :hdparm - get/set SATA/IDE device parameters so,the doc is out date, it should mention hdparm also support SATA. and this doc section current contains more IDE than SATA driver , but nowadays, IDE driver is nearly dead, it hardly buy one IDE hard disk on the market. so we should write more doc about SATA than IDE. best regards, -- Jov blog: http:amutu.com/blog <http://amutu.com/blog>