[gentoo-user] Re: recovering RAID from an old server
Should I be able to mount them automatically and let the SW RAID module sort it out or do I have to know how they're tied together beforehand? md: looking for a shared spare drive md100: no spare disk to reconstruct array! -- continuing in degraded mode md: recovery thread finished ... md: hde5 [events: 03a5]6(write) hde5's sb offset: 273024 md: hdg5 [events: 03a5]6(write) hdg5's sb offset: 273024 XFS mounting filesystem md(9,100) Ending clean XFS mount for filesystem: md(9,100) The partitions look like: 9 100 546112 md100 9 101 273024 md101 It seems it has correctly mounted its partition... Can't you find it? I have the feeling that you are messing it up. If I understand it correctly the server has an hardware RAID controller, that has to be managed via its drivers. Software RAID tools aren't suitable to mount correctly this setup, I would mount random partition for testing purposes only, on a spare machine. The wiser thing to do is find an old livecd supporting PERC SAS (or whatever raid card is in that Snap) RAID cards and assemble the array in degraded mode for data recovery. Another thing can come very useful: we once had a similar problem, we ended up borrowing one identical disc from another running server to put the array back online, we recovered our data, then restored the other server's array. HTH Francesco -- Linux Version 2.6.32-gentoo-r5, Compiled #2 SMP PREEMPT Wed Feb 17 20:30:02 CET 2010 Two 1GHz AMD Athlon 64 Processors, 4GB RAM, 4021.84 Bogomips Total aemaeth
Re: [gentoo-user] Re: recovering RAID from an old server
On Sat, 2010-02-20 at 10:46 +0100, Francesco Talamona wrote: Should I be able to mount them automatically and let the SW RAID module sort it out or do I have to know how they're tied together beforehand? md: looking for a shared spare drive md100: no spare disk to reconstruct array! -- continuing in degraded mode md: recovery thread finished ... md: hde5 [events: 03a5]6(write) hde5's sb offset: 273024 md: hdg5 [events: 03a5]6(write) hdg5's sb offset: 273024 XFS mounting filesystem md(9,100) Ending clean XFS mount for filesystem: md(9,100) The partitions look like: 9 100 546112 md100 9 101 273024 md101 It seems it has correctly mounted its partition... Can't you find it? This is with the server recovery console, which is basically just a web page. No shell access. There's not much I can do to get at md100 and md101 (is this what software RAID devices usually appear as?) I have the feeling that you are messing it up. If I understand it correctly the server has an hardware RAID controller, that has to be managed via its drivers. I think it's software RAID. There is no RAID controller AFAICT. All 4 drives are visible to the BIOS as Primary and Secondary Master and Slaves. Another thing can come very useful: we once had a similar problem, we ended up borrowing one identical disc from another running server to put the array back online, we recovered our data, then restored the other server's array. That's a possibility given what I can find on Google, however these are few and far between, so I'd have to find someone willing to send their drive to me (or vice versa) or send me the OS, which overlandstorage doesn't like! thanks, -- Iain Buchanan iaindb at netspace dot net dot au Come quickly, I am tasting stars! -- Dom Perignon, upon discovering champagne.
[gentoo-user] Re: recovering RAID from an old server
On Saturday 20 February 2010, Iain Buchanan wrote: On Sat, 2010-02-20 at 10:46 +0100, Francesco Talamona wrote: Should I be able to mount them automatically and let the SW RAID module sort it out or do I have to know how they're tied together beforehand? md: looking for a shared spare drive md100: no spare disk to reconstruct array! -- continuing in degraded mode md: recovery thread finished ... md: hde5 [events: 03a5]6(write) hde5's sb offset: 273024 md: hdg5 [events: 03a5]6(write) hdg5's sb offset: 273024 XFS mounting filesystem md(9,100) Ending clean XFS mount for filesystem: md(9,100) The partitions look like: 9 100 546112 md100 9 101 273024 md101 It seems it has correctly mounted its partition... Can't you find it? This is with the server recovery console, which is basically just a web page. No shell access. There's not much I can do to get at md100 and md101 (is this what software RAID devices usually appear as?) I have the feeling that you are messing it up. If I understand it correctly the server has an hardware RAID controller, that has to be managed via its drivers. I think it's software RAID. There is no RAID controller AFAICT. All 4 drives are visible to the BIOS as Primary and Secondary Master and Slaves. This isn't a proof: most hardware RAID are proprietary software solutions pretending to be hardware. Linux without the driver can't see the logical volume and shows all the physical drives. You should do some research about that server hardware... Aren't snap equipped with PERC controller?. Another thing can come very useful: we once had a similar problem, we ended up borrowing one identical disc from another running server to put the array back online, we recovered our data, then restored the other server's array. That's a possibility given what I can find on Google, however these are few and far between, so I'd have to find someone willing to send their drive to me (or vice versa) or send me the OS, which overlandstorage doesn't like! What happens if you physically remove the drive marked as bad? You may image it for backup, then format it at low level, then put it back in place as if it was brand new. Or add a similar disk to be considered spare by the controller (given that it is looking for a spare disk in first instance). Most controller have automated procedures to manage failures, disk swaps and so on. For this reason you can't be sure that the inspection operations you are doing are read only. Unless the drives are attached to another machine with a trusted OS doing nothing on its own. The ideas given above may let you to waste all of your data, be very careful and patient. Good luck. Francesco -- Linux Version 2.6.32-gentoo-r5, Compiled #2 SMP PREEMPT Wed Feb 17 20:30:02 CET 2010 Two 2.9GHz AMD Athlon 64 Processors, 4GB RAM, 11659 Bogomips Total aemaeth
