Barriers and journaling filesystems
Posted May 24, 2008 19:50 UTC (Sat) by giraffedata
Parent article: Barriers and journaling filesystems
Keeping the journal together will be good for performance, but it also helps to prevent reordering. In normal usage, the commit record will land on the block just after the rest of the journal data, so there is no reason for the drive to reorder things.
I don't see how that's true even usually. Even a classic elevator algorithm sweeps backward as well as forward. And if I were a disk drive with multiple blocks to write on the same track, I would not wait for the lowest numbered block to come around and write the track in order; I'd start writing whatever is under the head right now.
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