Il 17-08-2017 23:01 Roger Heflin ha scritto:
But even if you figured out which it was, you would have no way to know what writes were still sitting in the cache, it could be pretty much any writes from the last few seconds (or longer depending on how exactly the drive firmware works), and it would add additional complexity to keep a list of recent writes to validate actually happened in the case of an unexpected drive reset. This is probably more of a avoid this failure condition since this failure condition is not a normal failure mode and more of a very rare failure mode.
Yes, but having identified the power-cycled disk, the system can not take the most sensible action. For example, it can re-sync it with its mirror disk, basically treating it as a --add-spare action. Or it can simply considering the disk as failing, kicking off it from the array and sending an alert email.
What the system should not do is doing nothing: as differences accumulates, reading from the array become non-deterministic. In other words, two reads can produce two different results, based on what disk was queried. This *will* cause all sort of problems.
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