On Tuesday October 30, david@xxxxxxxxxxxx wrote: > Neil Brown wrote: > > On Monday October 29, kstuart@xxxxxxxxx wrote: > >> Hi, > >> I bought two new hard drives to expand my raid array today and > >> unfortunately one of them appears to be bad. The problem didn't arise > > > Looks like you are in real trouble. Both the drives seem bad in some > > way. If it was just sdc that was failing it would have picked up > > after the "-Af", but when it tried, sdb gave errors. > > Humble enquiry.... :) > > I'm not sure that's right? > He *removed* sdb and sdc when the failure occurred so sdc would indeed be non-fresh. I'm not sure what point you are making here. In any case, remove two drives from a raid5 is always a bad thing. Part of the array was striped over 8 drives by this time. With only six still in the array, some data will be missing. > > The key question I think is: will md continue to grow an array even if it enters > degraded mode during the grow? > ie grow from a 6 drive array to a 7-of-8 degraded array? > > Technically I guess it should be able to. Yes, md can grow to a degraded array. If you get a single failure I would expect it to abort the growth process, then restart where it left off (after checking that that made sense). > > In which case should he be able to re-add /dev/sdc and allow md to retry the > grow? (possibly losing some data due to the sdc staleness) He only needs one of the two drives in there. I got the impression that both sdc and sdb had reported errors. If not, and sdc really seems OK, then "--assemble --force" listing all drives except sdb should make it all work again. NeilBrown - 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
