Tomasz Chmielewski wrote: > > Creating 10000 directories *once* is a completely irrelevant test to > check BackupPC performance on a given filesystem.
Postmark used to show a big difference between ext2 and reiserfs. The source link from this page: http://packages.ubuntu.com/hardy/utils/postmark should work if you aren't on unbuntu/debian. You can give it big enough numbers to be sure it isn't all happening in ram and it times creating/deleting separately. > ...how well does it prevent > fragmentation, does it try to place certain inodes/blocks close to each > other etc. Backuppc's order of file and link creation will end up defeating the filesystem's best guess about what should be close together. > Heck, it's not only filesystem, but also IO scheduler that can make the > results *very* different. At least with Linux, I'm not familiar enough > with I/O scheduler algorithms and tuning in FreeBSD or Solaris to > discuss it. The scheduler shouldn't make much difference unless you have something else happening. The main thing that can help is making the writes as lazy as possible so you accumulate more operations that can be re-ordered to reduce seeks as they are done. >> *Blazing performance* >> ZFS is based on a transactional object model that removes most of >> the traditional constraints on the order of issuing I/Os, which >> results in huge performance gains. >> >> there is the I/O caching. zfs caches checks of I/O and then reorders >> it to do a large, more-sequential write. > > In Linux, that's a I/O scheduler domain: when small read latency is > needed, such behaviour may not be always desired. Increasing read latency might be a bad thing for rsync transfers - but it would be hard to measure that at the same time as disk write activity. -- Les Mikesell [EMAIL PROTECTED] ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ BackupPC-users mailing list [email protected] List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
