On Thu, Mar 29, 2007 at 03:16:44AM -0600, Andreas Dilger wrote: > On Mar 28, 2007 18:47 +0100, T. Horsnell wrote: > > 1. The effect on performance of large numbers of (generally) small files > > One of my ext3 filesystems has 750K files on a 36GB disk, and > > backup with tar takes forever. Even 'find /fs -type f -ls' > > to establish ownership of the various files takes some hours. > > Are there thresholds for #files-per-directory or #total-files-per-filesystem > > beyond which performance degrades rapidly? > > You should enable directory indexing if you have > 5000 file directories, > then index the directories. "tune2fs -O dir_index /dev/XXX; e2fsck -fD /dev/XXX" Thanks very much. Do you mean '> 5000 directories-per-filesystem' or '> 5000 files-per-directory' ? tune2fs refers to 'large directories' which implies to me that its files-per-directory Cheers, Terry. > > > 2. I have a number of filesystems on SCSI disks which I would > > like to fsck on demand, rather than have an unscheduled > > fsck at reboot because some mount-count has expired. > > I use 'tune2fs -c 0 and -t 0' to do this, and would like > > to use 'shutdown -F -r 'at a chosen time to force fsck on > > reboot, and I'd then like fsck to do things in parallel. > > What are the resources (memory etc) required for parallel > > fsck'ing? Can I reasonably expect to be able to fsck say, > > 50 300GB filesystems in parallel, or should I group them into > > smaller groups? How small? > > I think it was at least "(inodes_count * 7 + blocks_count * 3) / 8" per > filesystem when I last checked, but I don't recall exactly anymore. > > Cheers, Andreas > -- > Andreas Dilger > Principal Software Engineer > Cluster File Systems, Inc. > -- _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
