[rdiff-backup-users] extremely slow backups off OS X

[Kurt Yoder]

Hello all

I've seen some posts regarding slow rdiff-backups, but no suggestions  
on speeding them up. I've been experimenting with this program for  
the last week, and it looks extremely useful. However, if I can't  
resolve the slowness problem I'm going to have to give up on it.

I was previously backing up one of my Mac OS X boxen using using  
straight rsync. Here is an example run, along with duration:

/var/backups/rsync_scripts/paprika
Mon Jul 10 01:48:10 EDT 2006

Number of files: 769005
Number of files transferred: 36932
Total file size: 27633230023 bytes
Total transferred file size: 398646044 bytes
Literal data: 33119070 bytes
Matched data: 593205243 bytes
File list size: 18580399
Total bytes sent: 2711991
Total bytes received: 34505287

sent 2711991 bytes  received 34505287 bytes  16821.37 bytes/sec
total size is 27633230023  speedup is 742.48
end:
Mon Jul 10 02:25:02 EDT 2006


So using straight rsync, I was able to do a relatively large backup  
in approximately 40 minutes. After switching to rdiff backup, the  
initial backup took over 24 hours. The subsequent backups are taking  
approximately 6 1/2 hours:

# less session_statistics.2006-07-11T11\:50\:58-04\:00.data
StartTime 1152633058.00 (Tue Jul 11 11:50:58 2006)
EndTime 1152656310.11 (Tue Jul 11 18:18:30 2006)
ElapsedTime 23252.07 (6 hours 27 minutes 32.07 seconds)
SourceFiles 734136
SourceFileSize 25594604054 (23.8 GB)
MirrorFiles 734139
MirrorFileSize 25597749516 (23.8 GB)
NewFiles 5
NewFileSize 63692 (62.2 KB)
DeletedFiles 8
DeletedFileSize 3415368 (3.26 MB)
ChangedFiles 109
ChangedSourceSize 404526962 (386 MB)
ChangedMirrorSize 404320748 (386 MB)
IncrementFiles 124
IncrementFileSize 43212042 (41.2 MB)
TotalDestinationSizeChange 40066580 (38.2 MB)
Errors 0


On the "pull" side, I'm running Debian Linux, with a "backported"  
rdiff-backup version 1.1.5 (package 1.1.5-0bpo1). On the On the  
"client" side, I'm running Mac OS 10.4.7 with rdiff-backup from fink,  
version 1.1.5 (fink package rdiff-backup_1.1.5-1).

Can someone offer debugging suggestions so I can figure out why this  
is taking so long? A 975% increase in backup duration for rdiff- 
backup over rsync seems excessive.

Thanks

-Kurt