Date: Mon, 28 May 2001 19:49:40 +0200 From: Christoph Sold <so@server.i-clue.de> To: "E.B. Dreger" <eddy+public+spam@noc.everquick.net> Cc: hackers@FreeBSD.ORG Subject: Re: brainstorm: "intermediate" disk caching Message-ID: <3B128FB4.70AE7C69@i-clue.de> References: <Pine.LNX.4.20.0105281619110.5344-100000@www.everquick.net>
next in thread | previous in thread | raw e-mail | index | archive | help
"E.B. Dreger" schrieb: > > Greetings all, > > I just had a brainstorm... > > I was thinking about database servers with several spindles in a RAID 5 > array. Write performance is inherently disappointing -- which may or may > not be an issue. It is. Even RAID 1 is better than RAID 5 _for_database_use_. For added security, have run a RAID 10 array (basically, a mirrored stripe set). > Would it be worth the trouble to design an "intermediate" cache, whereby > data are quickly written to a spool disk, then to the final destination? > Sort of like softwares that cache CDROMs on HDD... > > My gut feel is that this would be more trouble than it's worth, would not > net any overall performance*reliability (expressed as a product) gain, and > that one might actually realize a p*r decrease. IMHO it would speed up your DB significantly to have it a) run on a RAID 10 array and b) have it run on the raw disk. Two layers of lag reduced (well, for reads it is possibly only one layer). HTH -Christoph Sold To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3B128FB4.70AE7C69>