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" > 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
