Title: Recovering a RAID volume with parity Post by: erkishhorde on October 06, 2009, 04:38:36 PM How the heck do I do it? :( I had 1 drive go kaput and now I can't access it anymore. I've got a new drive that I want to put in but it's not as straight forward as I was hoping. I should be able to get at all the data with only 2 drives, right? That's what parity means, isn't it?
Title: Re: Recovering a RAID volume with parity Post by: ZLTFUL on October 07, 2009, 03:08:01 AM RAID 0 yer hosed.
RAID 1 is mirrored so it should basically be 2 drives with the exact same data...easy fix. RAID 5 Stried with parity (involves 3+ drives so unlikely here) Other RAID arrays but they involve 3 or more drives and are unlikely. So what type of RAID array are we talking about? Title: Re: Recovering a RAID volume with parity Post by: minkman on October 07, 2009, 04:48:09 AM Also, hardware or software RAID? Hardware is done by the controller card or in the external enclosure. Software RAID is handled by the OS. I'm going to assume that you're running M$Windows, but if not, that's also important information.
ken Title: Re: Recovering a RAID volume with parity Post by: erkishhorde on October 07, 2009, 06:23:26 AM Ah, sorry, was just frustrated. Think I got it. It's a RAID5 with 3 drives. I think I'm running a hardware RAID too. I managed to get a bit of life back into the bad drive and left it rebuilding over night. Gonna quickly back it up as soon as it's finished. Still not sure how I'm supposed to recover my data with only 2 of the 3 drives but it looks like I won't have to.
Title: Re: Recovering a RAID volume with parity Post by: derby on October 07, 2009, 06:44:23 AM Ah, sorry, was just frustrated. Think I got it. It's a RAID5 with 3 drives. I think I'm running a hardware RAID too. I managed to get a bit of life back into the bad drive and left it rebuilding over night. Gonna quickly back it up as soon as it's finished. Still not sure how I'm supposed to recover my data with only 2 of the 3 drives but it looks like I won't have to. data on a raid5 volume with n-1 disks should still be accessible (albeit, with a performance penalty) without having to do anything. if you can't, i'd seriously question my configuration. with a software raid, evicting the failed disk and replacing it with a new one will likely require user interaction. Title: Re: Recovering a RAID volume with parity Post by: Mad Duc on October 07, 2009, 08:02:54 AM Most hardware based arrays I've worked with only pop up a notice/email when a drive goes bad - other wise I wouldn't have noticed other than slow access. What controller card is it? A cheapo card is bad mojo. Adaptec is the gold standard. If you really need the data then spend the money on a good controller card. Most raid volumes take a few hours to rebuild depending on the amount of data on them. The fuller the longer.
Title: Re: Recovering a RAID volume with parity Post by: ZLTFUL on October 07, 2009, 08:11:47 AM Adaptec is the gold standard. Kind of a misleading statement really...3Ware and Highpoint have vastly superior reputations when it comes to RAID controllers...and considering that Adaptec bases all of their designs off of 3Ware's previous generation cards, I would hardly consider them a gold standard. Fine for consumer grade but a roll of the dice when you get into enterprise level solutions... Title: Re: Recovering a RAID volume with parity Post by: Gator on October 07, 2009, 08:13:47 AM Did you try kicking it?
Title: Re: Recovering a RAID volume with parity Post by: Mad Duc on October 07, 2009, 08:47:34 AM Kind of a misleading statement really...3Ware and Highpoint have vastly superior reputations when it comes to RAID controllers...and considering that Adaptec bases all of their designs off of 3Ware's previous generation cards, I would hardly consider them a gold standard. Fine for consumer grade but a roll of the dice when you get into enterprise level solutions... It's been a while since I have been up on non FC stuff - most of our stuff is on private label FC controllers anymore so we don't get the privilege of knowing who actually made them. Title: Re: Recovering a RAID volume with parity Post by: erkishhorde on October 07, 2009, 10:45:08 AM I managed to get the data off by coaxing some life out of the bad drive. It actually doesn't seem to have anything wrong with it but I'm going to swap it out anyway.
Before it died on me my Intel Matrix Storage Manager popped up and told me it had to rebuild one of the my volumes. I thought, meh, whatever. But then it did it again the next time I booted up and then next time after that. That's odd. So I started running some tests on the drive that needed to be rebuilt before I backed anything up. Stupid idea. After I started running the tests it would show up as offline and the raid volume would fail and become inaccessible. |