On Thu, 18 Nov 2004 12:14:00 -0500 Dave Cramer <pg@xxxxxxxxxxxxx> wrote: > Andrew, > > Dell's aren't well known for their disk performance, apparently most > of the perc controllers sold with dell's are actually adaptec > controllers. Also apparently they do not come with the battery > required to use the battery backed up write cache ( In fact according > to some Dell won't even sell the battery to you). Also Dell's > monitoring software is quite a memory hog. > > Have you looked at top ?, and also hdparm -Tt /dev/sd? I haven't seen any PERC controllers that were really Adaptec ones, but I for one quit buying Dell RAID controllers several years ago because of poor Linux support and performance. On one machine (not a PostgreSQL server) we saw a 20% speed improvement by switching to software raid. If you have a test machine, I would suggest moving the data to a box without a RAID controller and see if you get better results. --------------------------------- Frank Wiles <frank@xxxxxxxxx> http://www.wiles.org ---------------------------------
