[rdiff-backup-users] Backing up a restore doubled rdiff-backup size

[Blair Zajac]

I use rdiff-backup to backup my wife's PowerBook's /Users/* directories and this 
weekend I upgraded it from 10.3 to 10.4 by doing the following steps:

1) Attach external Firewire drive.
2) Clone internal disk to external using Carbon Copy Cloner.
3) Wipe internal disk.
4) Install 10.4.
5) Drag and drop directories from external disk back into internal disk.

I tried a test on my Ubuntu box doing something like this, with the contents the 
same but the inode is different.  Rdiff-backup did a backup with no size change.

$ mkdir test
$ cp -p /etc/passwd test/
$ rdiff-backup test backup
$ cp -p /etc/passwd test/passwd1
$ mv test/passwd1 test/passwd
$ rdiff-backup test backup

So I was surprised when I got this report today.  I would assume that the diffs 
would be 0 size, so the incremental size of the repository would be very small, 
not almost a doubling of the size.

$ rdiff-backup --null-separator -v 5 --list-increment-sizes ashley-powerbook
ACLs not supported by filesystem at 
/var/rdiff-backups/ashley-powerbook/rdiff-backup-data
-----------------------------------------------------------------
Detected abilities for /var/rdiff-backups/ashley-powerbook/rdiff-backup-data 
(read only) file system:
  Access control lists                         Off
  Extended attributes                          On
  Case sensitivity                             On
  Mac OS X style resource forks                Off
  Mac OS X Finder information                  Off
-----------------------------------------------------------------
        Time                       Size        Cumulative size
-----------------------------------------------------------------------------
Sun Dec 18 22:48:07 2005         23.1 GB           23.1 GB   (current mirror)
Fri Dec 16 23:22:58 2005         21.6 GB           44.7 GB
Fri Dec 16 21:38:22 2005         6.54 MB           44.7 GB
Fri Dec 16 01:13:08 2005          197 MB           44.9 GB
Wed Dec 14 23:53:09 2005         61.1 MB           45.0 GB
Wed Dec 14 00:32:55 2005         6.49 MB           45.0 GB
Mon Dec 12 23:20:54 2005         25.2 MB           45.0 GB
Sun Dec 11 00:24:42 2005          458 MB           45.5 GB
Fri Dec  9 23:22:17 2005         16.9 MB           45.5 GB
Fri Dec  9 07:15:34 2005         8.70 MB           45.5 GB
Wed Dec  7 23:33:40 2005          162 MB           45.6 GB
Tue Dec  6 23:15:44 2005          290 MB           45.9 GB
Mon Dec  5 00:04:17 2005         1.12 GB           47.0 GB
Sun Dec  4 00:30:57 2005          210 MB           47.3 GB
Sat Dec  3 01:18:54 2005         68.1 MB           47.3 GB
Thu Dec  1 23:05:32 2005         22.9 MB           47.3 GB
Thu Dec  1 08:04:57 2005         9.17 MB           47.4 GB

$ cat session_statistics.2005-12-18T22:48:07-08:00.data
StartTime 1134974887.00 (Sun Dec 18 22:48:07 2005)
EndTime 1135021621.73 (Mon Dec 19 11:47:01 2005)
ElapsedTime 46734.57 (12 hours 58 minutes 54.57 seconds)
SourceFiles 71151
SourceFileSize 24738960103 (23.0 GB)
MirrorFiles 78164
MirrorFileSize 55819067916 (52.0 GB)
NewFiles 14191
NewFileSize 934670526 (891 MB)
DeletedFiles 21204
DeletedFileSize 31778439883 (29.6 GB)
ChangedFiles 56575
ChangedSourceSize 23804289577 (22.2 GB)
ChangedMirrorSize 24040628033 (22.4 GB)
IncrementFiles 91970
IncrementFileSize 23232724461 (21.6 GB)
TotalDestinationSizeChange -7847383352 (-7.31 GB)
Errors 0

I didn't restore a lof of the data that applications leave around, such as 
browser cache files and the like, so I can see the -7.31 GB, but seeing 
everything as changed is odd.

Or am I just mis-reading the information here?

Regards,
Blair

--
Blair Zajac, Ph.D.
<address@hidden>
Subversion and Orca training and consulting
http://www.orcaware.com/svn/