Date: Fri, 27 Jun 2008 14:38:13 +0930 From: Benjamin Close <Benjamin.Close@clearchain.com> To: Garrett Cooper <yanefbsd@gmail.com> Cc: Tom Evans <tevans.uk@googlemail.com>, current@freebsd.org, sos@freebsd.org Subject: Re: URGENT: Need help rebuilding iir RAID5 array with failed drive Message-ID: <486475BD.9030601@clearchain.com> In-Reply-To: <7d6fde3d0806262004u171bf9dx179564be5a76d9c7@mail.gmail.com> References: <7d6fde3d0806260649t6619521bv92b65c472ddb7e1@mail.gmail.com> <1214492963.35536.22.camel@localhost> <4863B968.4040805@clearchain.com> <7d6fde3d0806262004u171bf9dx179564be5a76d9c7@mail.gmail.com>
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Garrett Cooper wrote: > On Thu, Jun 26, 2008 at 8:44 AM, Benjamin Close > <Benjamin.Close@clearchain.com> wrote: > >> Tom Evans wrote: >> >>> On Thu, 2008-06-26 at 06:49 -0700, Garrett Cooper wrote: >>> >>> >>>> Hello, >>>> First off sorry for the cross-post. I typically don't do this >>>> but this is an important question, so please bear with me. I'm just >>>> trying to get more eyes on the subject so I can (maybe) get a reply >>>> quicker... >>>> I'm running 8-CURRENT on my machine and it appears that one of >>>> the disks in my RAID5 array has taken a nose dive (BIOS recognizes >>>> that it exists, but Intel Matrix Manager claims that the disk is an >>>> "Offline Member"). After doing some reading it appears that it's >>>> kaput, so I need to get a replacement disk to fix this one... >>>> That aside, I need to determine how to rebuild the array in a >>>> Unix environment because Intel only provides instructions for how to >>>> use their Windows matrix manager. If anyone can point me to some links >>>> or provide me with some pointers on how to correct this issue, I'd owe >>>> you a lot; in fact the next time you come by Santa Cruz, CA I'll >>>> gladly treat you to some beers or something else you might want :)... >>>> Linux solutions (if there isn't a proper one for FreeBSD) are valid, >>>> as long as the core data remains uncorrupted and I can do what I need >>>> to from a LiveCD. I'm just scared to boot up OS and have it do some >>>> irrevocable operation like fsck -y and assume parity errors are ok or >>>> something along those lines (I don't remember if I set rc.conf to >>>> fsck -y and I know I can change that from single-user mode, but I want >>>> to play things conservatively if at all possible) :\... >>>> Filesystem is UFS2 with softupdates of course. >>>> Point proven that I need to backup my data more often :(... >>>> TIA, >>>> -Garrett >>>> >>>> PS If replying on the questions@ list, please CC me as I'm not >>>> subscribed to that list. >>>> >>>> >>> I'm fairly sure that Intel Matrix metadata cant be created/modified by >>> fbsd, only read. You should be able to do whatever rebuild operations >>> you need in the BIOS I believe, but that would be an offline operation, >>> clearly. >>> >>> I may be mistaken, and the driver can handle array rebuilds for matrix. >>> If it can, the command you are looking for is 'atacontrol rebuild ar0', >>> see atacontrol(8). >>> >>> Tom >>> >>> >> Please DONT use FreeBSD to rebuild this RAID5 unit. FreeBSD will detect it >> as a raid 5 Unit and even allow you to use it, add the new disk to it and >> even let you rebuild the raid. >> However the ata driver does not have support parity for Raid5. From >> ataraid(4): >> >> RAID5 is not supported at this time. Code exists, but it neither uses >> nor maintains parity information. >> >> You can confirm this in code, just look for the Swedish comments in >> ataraid.c >> Hence writing to the raidset will give you a glorified raid0. >> >> Cheers, >> Benjamin >> > > So.. wait a sec? Are you saying I'm fscked because my RAID5 is nothing > more than RAID0 under FreeBSD?!?! > If you've been writing to the RAID5 under FreeBSD, then yes. You've got a glorified paper weight and sadly your data is most likely lost. I've had a bug report http://www.freebsd.org/cgi/query-pr.cgi?pr=bin/106431 unanswered for some time about at least warning users about this. For the future I'd recommend either zfs of the geom suite (gmirror, etc). Benjaminhome | help
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