On Thu, Sep 16, 2010 at 6:22 PM, Tyler Gillies <[email protected]> wrote: > Wow, thanks for the thought out writeup! >
here's a blog post http://letsgetdugg.com/2010/06/25/couchdb-on-zfs/ > On Thu, Sep 16, 2010 at 12:47 PM, Randall Leeds > <[email protected]>wrote: > >> Disclaimer: I'm no file systems expert. >> >> I recommend something with extents otherwise you might take a big >> performance hit while couch deletes old db files after compaction. >> Compression sounds cool as long as you can do it really fast (are >> there setups where this happens in hardware?). >> >> reiserfs: >> According to wikipedia it "still uses the big kernel lock (BKL) — a >> global kernel-wide lock" which makes performance on multiple cores >> suffer. >> It's big benefit, as I always understood it, is being able to pack >> smile files together into single blocks. You will likely not have lots >> of small files with Couch :-P >> >> xfs: >> Delayed allocation might be a big performance win with a Couch. Since >> outstanding writes are committed together in chunks and then fsync'd >> all together I bet this feature would do good things for Couch >> performance. >> >> ext(3|4) >> I'd recommend ext4 over ext3. Delayed allocation like xfs as well as >> the multiblock allocator should make it much better than ext3. You >> also get extents. >> >> btrfs/zfs: >> Some of the features of each sound interesting, but nothing that >> stands out to me as "great for CouchDB". Snapshots and backups are >> cool, but Couch is doing this for you already in a sense due to the >> way the btree is appended: CouchDB documents are, in a sense, >> copy-on-write. Checksumming is cool if you think it's important for >> your data integrity. If you want snapshots for backup you can always >> use CouchDB replication. >> >> If you run any tests I'd be very, very interested in seeing your results. >> >> -Randall >> >> On Thu, Sep 16, 2010 at 03:11, Metin Akat <[email protected]> wrote: >> > I'm sure almost everybody out there is using ext4/3 (including me), >> > but what about filesystems like btrfs, zfs, reiserfs, xfs. Some of >> > them have very appealing feature-sets (like compression for example, >> > and we all know how greedy is couchdb for disk space). >> > And I know that for example btrfs is not yet "recommended for >> > production". But its time is coming. From what I see, Ubuntu 10.10 >> > works flawlessly on btrfs. >> > So I'd be happy if we have some discussion on the topic, instead of >> > "everybody uses ext4, just use it" kind of stuff :). >> > Couchdb was "alpha software" for years, and we all used it in >> > production, so we are not afraid of alpha/beta software, as long as >> > it's good :) >> > > > > -- > http://www.readwriteweb.com/about#tyler > > Ask me anything <http://tumble.pdxbrain.com/ask>! > -- Chris Anderson http://jchrisa.net http://couch.io
