Paul Clements <paul.clements@xxxxxxxxxxxx> wrote:
I don't see that this solves anything. If you had both sides going at
once, receiving different writes, then you are sc&**ed, and no
resolution of bitmaps will help you, since both sides have received
different (legitimate) data. It doesn't seem relevant to me to consider
You're forgetting that journalling filesystems and databases have to replay their journals or transaction logs when they start up.
What about when A comes back up? We then get a
.--------------. system A | system B | nbd ---' [raid1] | | / \ | [disk] [disk] [nbd]-'
situation, and a resync is done (skipping clean sectors).
You're forgetting that there may be some data (uncommitted data) that didn't reach B that is on A's disk (or even vice versa). That is why you've got to retrieve the bitmap that was in use on A and combine it with B's bitmap before you resync from B to A (or do a full resync).
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