First off, I'm a happy user of BackupPC; I'm only posting because I have an architecture question resulting in bad performance that I'm hoping someone can answer.
I have a need to back up Windows clients. I got smb-based backups working very well, or so I thought -- no matter what I tried, I couldn't get some files backed up, even though the backuppc user was in the Administrators group and I had run icacls to grant backuppc full file rights. So I went through the trouble of setting up rsyncd and now I'm backing up every file without an issue, except that things are moving VERY slowly, even for new files that haven't been backed up before. With smb, which used smbclient to do the transfers, I was seeing transfer speeds of 40-65MB/s over a gigabit network -- with rsync-based backups, I am seeing about 6MB/s, ten times slower. I profiled File::RsyncP which is what BackupPC_dump appears to be using, and found this troubling report after a profile time of one day: time elapsed (wall): 86034.3727 time running program: 85959.5328 (99.91%) time profiling (est.): 74.7665 (0.09%) %Time Sec. #calls sec/call F name 83.30 71605.7838 913708 0.078368 ? File::RsyncP::pollChild 15.98 13737.1191 261 52.632640 File::RsyncP::writeFlush 0.21 176.3028 121432 0.001452 File::RsyncP::getData (snip) As you can see, pollChild is called a ridiculously large number of times, which is eating up nearly 70% of the CPU time trying to do a backup. This is extremely inefficient and completely explains why my backups are taking so long over rsync (the CPU spends most of it's time in pollChild). So, my questions are: - Is there a reason BackupPC needs to emulate rsync through File::RsyncP instead of just using rsync itself? - If not, is anyone maintaining File::RsyncP who can optimize that code and/or redesign it? Thanks in advance for any advice. -- Jim Leonard ([email protected]) http://www.oldskool.org/ Help our electronic games project: http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/ A child borne of the home computer wars: http://trixter.wordpress.com/ ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ 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/
