On 3/27/07, Les Mikesell <[EMAIL PROTECTED]> wrote: > Evren Yurtesen wrote: > > >> What is wall clock time for a run and is it > >> reasonable for having to read through both the client and server copies? > > > > I am using rsync but the problem is that it still has to go through a > > lot of hard links to figure out if files should be backed up or not.
Evren, I didn't see that you mentioned a wall clock time for your backups? I want to know how many files are in a single backup, how much data is in that backup and how long it takes to perform that backup. > From the perspective of the backup directories, it doesn't matter > whether or not there are additional links to a file. It just looks at > the directory entry to find the file it wants. It may matter that the > inodes and file contents end up splattered all over the place because > they were written at different times, though. Yep, Lee is right here. Unless BSD handles hard-links in some crazy manner. > > If you check namesys.com benchmarks, you will see that they only tested > > reiserfs against ext2/ext3/xfs/jfs and conveniently forgot to test > > against ufs2. > > > > You can see in the end of the page that slight performance increase in > > reiserfs is also bringing twice the cpu usage! (plus extX is faster in > > certain operations even) > > http://www.namesys.com/benchmarks.html When your overall speed is limited by the speed of your disks and your CPU spends all it's time twiddling it's thumbs waiting for disk, who cares if CPU doubles and still spends 90% of it's time waiting as long as it gets the job done faster? To summarize Evran's setup: FreeBSD, 250MB ram, CPU unknown, 1 7200rpm Seagate ATA disk Filesystem: ufs2, sync, noatime Pool is 17.08GB comprising 760528 files (avg file size ~22KB) BackupPC reports backup speeds between 0.06 -> 0.22 MB/s Total backup time per host: Unknown CPU is 99% idle during backups Disk shows ~75 IO/s during load and low transfer rate Says even small backup w/small number of files is slow. Can you try mounting the backup partition async so we can see if it really is read performance or write performance that is killing backup performance? I would also highly recommend that you limit backups to 1 concurrent backup at a time. I must wonder if ufs2 is really bad at storing inodes on disk... BTW, how does BackupPC calculate speed? I think it calculates backup speed by reporting files transferred over time, so if you don't have many files that change, won't BackupPC report a very low backup speed. -Dave ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ BackupPC-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/backuppc-users http://backuppc.sourceforge.net/
