Posted Feb 2, 2006 16:06 UTC (Thu) by anton
In reply to: snapshots?
Parent article: MD / DM
Log-structured filesystems are one of those things that seem
terribly neat at the start --- Recant was originally going to be a
log-structured FS --- but I spent some time trying to figure out a way
to expire them without doing a massive pass over the entire disk and
vast memory consumption and never thought of a way.
Well, I also failed to see a good way for combining the segments and
garbage collection ideas of the original LFS proposals with snapshots
and clones; moreover, the speed disadvantages of using a free-blocks
approach seem to have been mostly eliminated by clustering and delayed
But other ideas and properties of log-structured file systems still
seem to be worthwhile to me, in particular the possibility of having
decent data consistency guarantees and snapshots. So my thoughts have
turned to implementing LFSs with mostly conventional free-blocks
management, and I have written up these ideas.
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