Why object data mutations (write IOs to an object)
can't be tracked using old-school bitmap?
That's what I call "write intent journaling" %) it's still a sort of
"journaling" because you first modify the bitmap, fsync it, then proceed with
the write itself. Ceph/Pech architecture, however, dictates that an RBD spans multiple
OSDs. Because if it doesn't it stops being Ceph and becomes Linstor. :) and there is a
Linstor already. :) in this case it seems that a journal is more convenient than a plain
bitmap... aaand this is precisely what PGlog is (pglog isn't a journal with data, it
only contains a list of updated objects).
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With best regards,
Vitaliy Filippov