| |||||||||||||
XFS: the filesystem of the future?XFS: the filesystem of the future?Posted Jan 23, 2012 18:48 UTC (Mon) by martinfick (subscriber, #4455)In reply to: XFS: the filesystem of the future? by drag Parent article: XFS: the filesystem of the future?
It seems unfair to say that dedupe is overrated if you are only basing this on a single implementation (ZFS). There are many ways to dedupe which do not suffer from the same RAM problem (COW comes to mind), and I suspect that many more will be implemented in the future.
Also I suspect that you may not have considered that while RAM indeed is expensive compared to disks, if implemented properly deduping files will actually save RAM when a single file can be cached instead of many. Vserver unification, while not a full featured dedup, does allow for this RAM savings which can be huge in virtualised environments (and more).
(Log in to post comments)
XFS: the filesystem of the future? Posted Jan 24, 2012 21:42 UTC (Tue) by wazoox (subscriber, #69624) [Link]
Generally speaking, dedupe is trading CPU and RAM for storage space. It has also the serious drawback of making many sequential IOs random. It probably makes sense when your storage stack is horribly expensive, or when you really need to squeeze out some more bandwidth on a replicated system, etc. However given current hard drives prices (even with the current 50% price hike) and subsystem performance (any 500 bucks RAID card can do 1 GB/s), it's almost always a gain only for the vendor.
XFS: the filesystem of the future? Posted Jan 24, 2012 22:36 UTC (Tue) by khim (subscriber, #9252) [Link] On the other hand dedupe is pretty good fit for SSD. SSD is expensive (albeit less expensive then RAM) and seeks are not as important.
XFS: the filesystem of the future? Posted Jan 25, 2012 7:48 UTC (Wed) by wazoox (subscriber, #69624) [Link]
That's true, but so far dedupe is mostly touted for secondary-level storage, so SSDs are a bit of a stretch.
|
|||||||||||||