John McMonagle <johnm@xxxxxxxxxxx> wrote: > I am concerned what will happen if the computer dies while writing a strip. Well, the strip will be partially written. > Is it possible that the stripe will be corrupted? No - it will be partially written. The parity data may or may not be consistent with the real data at that point, and if you lose a disk before the next resync (at next reboot) you may get some different data reconstructed using parity than if you had used the data itself. OTOH if you reboot with all disks intact the parity will be reconstructed properly and the inconsistency will be removed. But any missed writes will remain missing. > If so will the the rest of the raid array be OK? Apart from that strip? I'm not sure exactly what you mean by "strip" (probably some raid jargon? Don't they use "chunks" and "stripes"?)! But clearly the data inconsistency will be confined to it. > if so is there anything one can do about it? ? Nothing has happened - you have simply not written all the data you wanted to write. This happens all the time when writing to disks and crashing your computer! But since raid writes at least twice, once for data and once for parity, you have the extra pssibility of having missed some of the parity data (or having written parity but not data). That produces an inconsistency in the redundant data. You can fix it by rebooting with all disks intact. Hey - you even fix the inconsistency by rebooting with one missing; you just have less chance of reconstructing the intended data that way. Peter - 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
