Comments on: Real-life RAID reliability http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/ Storage Solutions for Real World IT Professionals Sat, 21 Nov 2009 05:28:26 +0000 http://wordpress.org/?v=1.5.2 Comment on Real-life RAID reliability by: Tom http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-84616 Thu, 01 Nov 2007 17:24:32 +0000 http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-84616 Oops. Link is fixed. Sorry about that. And <a href="http://graphics.adaptec.com/us/TT_SA/MTTDL.xls">here</a> it is again just so you don't have to scroll back to find it. Enjoy! TT Oops. Link is fixed. Sorry about that.

And here it is again just so you don’t have to scroll back to find it.

Enjoy!
TT

]]> Comment on Real-life RAID reliability by: Camruin http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-78664 Fri, 05 Oct 2007 15:43:19 +0000 http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-78664 It looks like the link to the spreadsheet is broken. Do you still have it around somewhere? It looks like the link to the spreadsheet is broken. Do you still have it around somewhere?

]]> Comment on Real-life RAID reliability by: Chris Carrier http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-76904 Wed, 26 Sep 2007 12:38:56 +0000 http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-76904 Hi Tom. I was very interested in seeing your spreadsheet as referenced in the comments above, but the link appears to be broken. Is there any way to repost or resend? Thanks, Chris Hi Tom.

I was very interested in seeing your spreadsheet as referenced in the comments above, but the link appears to be broken. Is there any way to repost or resend?

Thanks,
Chris

]]> Comment on Real-life RAID reliability by: Tom http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-33159 Sat, 10 Feb 2007 14:26:00 +0000 http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-33159 Ernst, I think mixing drives can make sense for folks that need one volume of cheap, slow storage and one volume of expensive, fast storage. Most enclosures support up to 12 drives, so combining the two drive types is probably reasonable. But I'd certainly agree that combining SAS and SATA in one array is crazy. We did this test for a variety of enclosures just to see how well (or poorly) they could isolate each drive from the RV effects of other drives. We were frankly surprised at the difference. I forget which drives we used, but we didn't really try too many different drive types. The test was all about enclosures. But maybe we can re-run these test with some of the new nearline drives. I'll see if I can talk someone into doing that... Ernst, I think mixing drives can make sense for folks that need one volume of cheap, slow storage and one volume of expensive, fast storage. Most enclosures support up to 12 drives, so combining the two drive types is probably reasonable. But I’d certainly agree that combining SAS and SATA in one array is crazy.

We did this test for a variety of enclosures just to see how well (or poorly) they could isolate each drive from the RV effects of other drives. We were frankly surprised at the difference. I forget which drives we used, but we didn’t really try too many different drive types. The test was all about enclosures. But maybe we can re-run these test with some of the new nearline drives. I’ll see if I can talk someone into doing that…

]]> Comment on Real-life RAID reliability by: Ernst Lopes Cardozo http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-32914 Fri, 09 Feb 2007 18:31:17 +0000 http://storageadvisors.adaptec.com/2005/11/02/actual-reliability-calculations-for-raid/#comment-32914 "SATA drives ... dropped to around 10% of their normal performance". Wow! However, mixing SAS and SATA drives in one box runs against popular wisdom. Did you run a similar test with all SAS and all SATA drives? “SATA drives … dropped to around 10% of their normal performance”. Wow! However, mixing SAS and SATA drives in one box runs against popular wisdom. Did you run a similar test with all SAS and all SATA drives?

]]>