[rdiff-backup-users] Error 1? Final moment permissions problem on target?

[Ron Leach]

List, good morning,

We're in the middle of moving our backup destination from an old 
machine (with only 2TB) to a new one with 6TB space; each of these is 
on a separate NFS share mounted under /mnt.  Our migration scheme is 
straightforward, but we hit a problem, possibly with permissions, and 
I don't understand what to do.

Migration steps:

(1) Halt the regular rdiff-backups, by commenting out the invocations 
in crontab

(2) Using the same user as the user who runs the rdiff-backups, copy 
the existing target repository onto the new destination server;
$ cd /mnt/exist-dest
$ cp -a -u -v .* -t/mnt/new-dest

(3) Execute rdiff-backup using the new machine as the destination
$ rdiff-backup --print-statistics -v3 --exclude /Source/.Trash-1000 
/Source /mnt/new-dest

(4) Check the log/report and, if ok, restore the automatic cron 
invocations, edited to backup to the new destination.


We hit a problem, though, and I don't understand what to do to fix it.

Step 2 reported an error when the cp command finished:
cp: preserving times for `/mnt/new-dest/.': Operation not permitted

The files had all 'seemed' to copy across ok, so I went ahead with 
step 3.  But step 3 failed also, at what was close to its final step 
(judging by the sequence of the timestamps on the various directories 
and files in the new destination):

Exception '[Errno 1] Operation not permitted: '/mnt/new-dest'' raised 
of class '<type 'exceptions.OSError'>':

The calling tree seems to indicate a permissions cause:
[ ..... ]
File "/var/lib/python-support/python2.5/rdiff_backup/rpath.py", line 
927, in chmod
    self.conn.os.chmod(self.path, permissions & Globals.permission_mask)

called from:
[ ....... ]
File "/var/lib/python-support/python2.5/rdiff_backup/backup.py", line 
664, in end_process
    rpath.copy_attribs(self.dir_update, self.base_rp)
File "/var/lib/python-support/python2.5/rdiff_backup/rpath.py", line 
189, in copy_attribs
    rpout.chmod(rpin.getperms())
File "/var/lib/python-support/python2.5/rdiff_backup/rpath.py", line 
927, in chmod
    self.conn.os.chmod(self.path, permissions & Globals.permission_mask)

OSError: [Errno 1] Operation not permitted: '/mnt/new-dest'


I am sure I've set something up incorrectly on the new destination, 
but the user can read and write to it so I am not sure why there might 
be a problem.  I'd also tried to make sure that the new-destination 
had the same permissions as the old-destination.  Two questions I 
would like to ask are what is the significance of the error that cp 
reported?  And what permissions 'ought' to exist on the rdiff-backup 
destination?

I'd be grateful for any comments.  I am not confident about 
permissions, in general, so even very basic remarks would be very welcome.

regards, Ron