Jon Hardcastle <jd_hardcastle@xxxxxxxxx> writes: > --- On Wed, 26/8/09, Goswin von Brederlow <goswin-v-b@xxxxxx> wrote: > >> From: Goswin von Brederlow <goswin-v-b@xxxxxx> >> Subject: Re: Raid 5 - not clean and then a failure. >> To: Jon@xxxxxxxxxxxxxxx >> Cc: linux-raid@xxxxxxxxxxxxxxx >> Date: Wednesday, 26 August, 2009, 12:18 PM >> Jon Hardcastle <jd_hardcastle@xxxxxxxxx> >> writes: >> >> > Guys, >> > >> > I have been having some problems with my arrays that I >> think i have nailed down to a pci controller (well I say >> that - it is always the drives connected to *a* controller >> but I have tried 2!) anyway the latest saga is i was trying >> some new kernel options last night - which didn't work. >> > >> > But when i booted up again this morning it said one of >> the drives was in an inconsistent state (not sure of the >> *exact* error message). I then kicked off an add of the >> drive and it started syncing. It got about 5% in and then >> the second drive in on that controller complained and the >> array failed. >> > >> > Is there any hope for my data? If i get a good >> controller in there will the resync continue? can I try and >> tell it to assume the drives are good (which they ought to >> be)? >> > >> > Please help! >> >> The inconsistency is probably just a block here or there >> and I'm >> assuming none of your drives actualy failed. So 99.9999% of >> your data >> should be there. Just rebooting might actualy just get your >> raid back >> (to syncing). If not then you have to force reassembly from >> the drives >> with the newest serials. That will give you some data >> corruption, >> whatever was writing when the controler gave errors. Worst >> case you >> have to recreate the raid with --assume-clean. >> >> I recommend adding a bitmap to the raid. That way a >> wrongfully failed >> drive can be resynced in a matter of minutes instead of >> hours or >> days. Makes it way less likely another error occurs during >> resync. >> >> MfG >> Goswin >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-raid" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > I did look into bitmaps *abit* i could easily have the imagine for my 6 drive raid 5 stored on the raid1 I have in the same system.. The googling I did tho did not paint a pretty picture it talked about huge performance hits? That depends on the bitmap size a lot. It also depends on the frequency of errors. If your controler has a hickup once a week causing a drive to fail and you need 1 day to rebuild the array you will be left with a double disk failure pretty quickly without bitmaps. MfG Goswin -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
