My personal experience with RAID cards is that you have to spend money to get good performance. You need battery backed cache because RAID 5 only works well with write to cache turned on, and you need a good size cache too. If you don't have it, RAID 5 performance will suck big time. If you need speed, RAID 10 seems to be the only way to go, but of course that means you are gonna spend $$s on drives and chasis. I wish someone would start a website like storagereview.com for RAID cards because I have had _vastly_ differing experience with different cards. We currently have a compaq ML370 with a Compaq Smart Array 5300, and quite frankly it sucks (8MB/sec write). I get better performance numbers off my new Tyan Thunder s2469UGN board with a single U320 10k RPM drive (50MB/sec) than we get off our RAID 5 array including seeks/sec. Definately shop around, and hopefully some other folks can give some suggestions of a good RAID card, and a good config.
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Alex Turner P.S. If there is movement for a RAID review site, I would be willing to start one, I'm pretty dissapointed at the lack of resources out there for this. On Fri, Sep 12, 2003 at 10:34:26AM -0400, Jeff wrote: > Due to various third party issues, and the fact PG rules, we're planning > on migrating our deplorable informix db to PG. It is a rather large DB > with a rather high amount of activity (mostly updates). So I'm going to > be aquiring a dual (or quad if they'll give me money) box. (In my testing > my glorious P2 with a 2 spindle raid0 is able to handle it fairly well) > > What I'm wondering about is what folks experience with software raid vs > hardware raid on linux is. A friend of mine ran a set of benchmarks at > work and found sw raid was running obscenely faster than the mylex and > (some other brand that isn't 3ware) raids.. > > On the pro-hw side you have ones with battery backed cache, chacnes are > they are less likely to fail.. > > On the pro-sw side you have lots of speed and less cost (unfortunately, > there is a pathetic budget so spending $15k on a raid card is out of the > question really). > > any thoughts? > > -- > Jeff Trout <[EMAIL PROTECTED]> > http://www.jefftrout.com/ > http://www.stuarthamm.net/ > > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED] ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
