[BackupPC-users] Uneffective rsync transfers?

[František S. <fra...@st...>]

Hello.

I've started experimenting with rsync xfer method and I've found that 
the rsync transfers always the changes against the last backup.
There is a directory "testdir" with 3 files.

First full backup:
~~~~~~~~~~~~~~~~~~
full backup started for directory /testdir/
Running: /usr/bin/ssh -q -x -l root localhost /usr/bin/rsync --server 
--sender --numeric-ids --perms --owner --group -D --links --hard-links 
--times --block-size=2048 --recursive . /testdir/
Xfer PIDs are now 27260
Got remote protocol 30
Negotiated protocol version 28
Xfer PIDs are now 27260,27468
   create d 755       0/0        4096 .
   create   644       0/0     1048576 testfile1
   create   644       0/0     1048576 testfile2
   create   644       0/0     1048576 testfile3
Done: 3 files, 3145728 bytes

It's what I've expected. First backup, everything is transferred.
Try to do next backup without any changes.

Second full backup (when 0 files changed):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
full backup started for directory /testdir/ (baseline backup #0)
Running: /usr/bin/ssh -q -x -l root localhost /usr/bin/rsync --server 
--sender --numeric-ids --perms --owner --group -D --links --hard-links 
--times --block-size=2048 --recursive . /testdir/
Xfer PIDs are now 27502
Got remote protocol 30
Negotiated protocol version 28
Xfer PIDs are now 27502,27551
   create d 755       0/0        4096 .
Done: 0 files, 0 bytes
Got fatal error during xfer (No files dumped for share /testdir/)
Backup aborted (No files dumped for share /testdir/)
Not saving this as a partial backup since it has fewer files than the 
prior one (got 0 and 0 files versus 0)

Shouldn't be this considered as "non error" status? It means no files 
were changed. I think it is an correctly finished full backup with no 
files changed, but backuppc evaluates it as "Got fatal error during xfer".
Next try - I've added one new file, other files remain unchanged.

Second full backup (when 1 file added):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
full backup started for directory /testdir/ (baseline backup #0)
Running: /usr/bin/ssh -q -x -l root localhost /usr/bin/rsync --server 
--sender --numeric-ids --perms --owner --group -D --links --hard-links 
--times --block-size=2048 --recursive . /testdir/
Xfer PIDs are now 28931
Got remote protocol 30
Negotiated protocol version 28
Xfer PIDs are now 28931,28980
   create d 755       0/0        4096 .
   create   644       0/0     1048576 testfile4
Done: 1 files, 1048576 bytes.

It seems to be okay. Only the new file was transferred. But when I look 
in the web gui at this full backup, I see only this file. The other 
files (testfile1,2,3) are not here. Shouldn't be the full backup really 
full (merged somehow with the previous full backup)? After te previous 
full backup will be deleted, this backup will be almos useless..
I've continued testing. No changes in the testdir, run another full backup.

Third full backup (when 0 files changed after the previous backup):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
full backup started for directory /testdir/ (baseline backup #1)
Running: /usr/bin/ssh -q -x -l root localhost /usr/bin/rsync --server 
--sender --numeric-ids --perms --owner --group -D --links --hard-links 
--times --block-size=2048 --recursive . /testdir/
Xfer PIDs are now 29029
Got remote protocol 30
Negotiated protocol version 28
Xfer PIDs are now 29029,29078
   create d 755       0/0        4096 .
   create   644       0/0     1048576 testfile1
   create   644       0/0     1048576 testfile2
   create   644       0/0     1048576 testfile3
Done: 3 files, 3145728 bytes

Again. Only the files that are not present in the previous backup are 
present.
Next try. Next full backup, no files changed..

Fourth full backup (when 0 files changed after the previous backup):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
full backup started for directory /testdir/ (baseline backup #2)
Running: /usr/bin/ssh -q -x -l root localhost /usr/bin/rsync --server 
--sender --numeric-ids --perms --owner --group -D --links --hard-links 
--times --block-size=2048 --recursive . /testdir/
Xfer PIDs are now 30426
Got remote protocol 30
Negotiated protocol version 28
Xfer PIDs are now 30426,30474
   create d 755       0/0        4096 .
   create   644       0/0     1048576 testfile4
Done: 1 files, 1048576 bytes

And again. Only the files that are not present in the previous backup 
are present.

Is this a normal behavior? Is there a way to configure backuppc to 
transfer only changed files and merge them with the previous backup? I 
want to backup 200GB of email files. There will be only small amount of 
changes. If it will work as described, it transfers everything, then 
only the changes, then everything except the last changes and so on..

My testing config file:
~~~~~~~~~~~~~~~~~~~~~~~
$Conf{XferMethod} = 'rsync';
$Conf{ClientNameAlias} = 'localhost';
$Conf{RsyncShareName} = ['/testdir/'];

$Conf{BackupsDisable} = 1;
$Conf{FullKeepCnt} = 10;
$Conf{IncrKeepCnt} = 5;

Thank you.
With regards,
Frantisek Stary.