[rdiff-backup-users] running rdiff-backup on an rsync-ed disk

[Cybertinus]

Hello everybody,

First let me explain what my backupplan is:
I have 3 backup disks. The first one is mounted on /backup. The second
one is mounted on /backup_sync. The third one isn't mounted at my
computer. It is at an off-site location. Once a week I disconnect the
disk mounted on /backup and place that on at the off-site location. The
old off-site disk gets mounted on /backup_sync. The disk that used to be
on /backup_sync has moved to /backup at that time.
I've got a script that creates a backup to /backup. This script is a
small wrapper around rdiff-backup. Then I also have a small script which
is a wrapper around rsync. This script copies everything from /backup to
/backup_sync.

So far the theory :). In practice this idea fails a bit. rsync copies
everything nicely, I don't get any errors there. But when I swap the
disks, rdiff-backup doesn't work anymore I get the following stacktrace
(first and last line are created with my wrapper arround rdiff-backup):

Starting backup of /home/mysql at Mon Jun 22 13:31:39 CEST 2009
Exception 'Found too many current_mirror incs!' raised of class '<type
'exceptions.AssertionError'>':
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
304, in error_check_Main
    try: Main(arglist)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
324, in Main
    take_action(rps)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
280, in take_action
    elif action == "backup": Backup(rps[0], rps[1])
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
337, in Backup
    backup_final_init(rpout)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
501, in backup_final_init
    checkdest_if_necessary(rpout)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
916, in checkdest_if_necessary
    need_check = checkdest_need_check(dest_rp)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
907, in checkdest_need_check
    assert len(curmir_incs) == 2, "Found too many current_mirror incs!"

Traceback (most recent call last):
  File "/usr/bin/rdiff-backup", line 30, in <module>
    rdiff_backup.Main.error_check_Main(sys.argv[1:])
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
304, in error_check_Main
    try: Main(arglist)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
324, in Main
    take_action(rps)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
280, in take_action
    elif action == "backup": Backup(rps[0], rps[1])
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
337, in Backup
    backup_final_init(rpout)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
501, in backup_final_init
    checkdest_if_necessary(rpout)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
916, in checkdest_if_necessary
    need_check = checkdest_need_check(dest_rp)
  File "/usr/lib64/python2.6/site-packages/rdiff_backup/Main.py", line
907, in checkdest_need_check
    assert len(curmir_incs) == 2, "Found too many current_mirror incs!"
AssertionError: Found too many current_mirror incs!
Deleting increments at times:
Fri Jun  5 19:00:03 2009
Fri Jun  5 23:13:59 2009
Thu Jun 11 00:00:01 2009
Thu Jun 11 14:00:01 2009
Thu Jun 11 15:00:01 2009
Thu Jun 11 16:00:01 2009
Thu Jun 11 17:00:01 2009
Fri Jun 12 00:00:01 2009
Fri Jun 12 12:00:01 2009
Thu Jun 18 23:00:01 2009
Sat Jun 20 00:00:04 2009
Sat Jun 20 13:00:02 2009
Done backing up /home/mysql at Mon Jun 22 13:31:41 CEST 2009


This is my rsync command:
rsync --archive --hard-links --executability --acls --xattrs /backup/ 
/backup_sync
(the actual backupscript is a bit larger, it has a few checks to prevent it from 
doing the wrong stuff.).

What is going wrong and what must I do to solve this? Thnx for reading.

Regards,
Cybertinus