On Thu, 16 Jul 2015 11:07:34 -0400 "John Stoffel" <john@xxxxxxxxxxx> wrote: > > So.... how will wrapping of sequence numbers be handled in the cache > metadata on disk? They can't grow for ever... Can't they? A 64bit number incremented every millisecond can grow for half a billion years. As far as I'm concerned, that is forever. But even if we used 32bit numbers, it is very easy to handle looping providing you have few than half of the numbers in use at any time. So as long as we don't have more than 2 billion active transactions in the log at once, there is no problem. The kernel does some internal time keeping using "jiffies" which, on 32bit systems, cycle about every fortnight. A small amount of care is enough that this doesn't cause problem. 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
