[ ... ] > During a resync (after an unclean shutdown) the devices are > indistinguishable. RAID1 reads all drives and if there is a > difference it chooses one data block to write to the others - > always the one with the lowest index number. Uhhhhh "indistinguishable" and "lowest index number"? Shouldn't that be "lowest index number among those with the highest event count"? Put another way, couldn't it happen that in a 5-way RAID1 for example an unclean shutdown results in 2 drives with the same highest event count and 3 drives with lower event counts, and then the data page to write is that from the one of the 2 with the lowest index number and is written only to the 3 with the lower event count? Also, in case of an «unclean shutdown» resulting in all members of a RAID1 set having the same event count, is the resync still done? Is it necessary? Or is «unclean shutdown» used here as an alias for "not all event counts are the same". I am asking as to what RAID1 actually does mostly, but also perhaps as to what it ought to be doing. -- 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
