Innop <innop.mail <at> gmail.com> writes:

> But the protocol Rsync does it not based on the incremental backup?

Right.  The only thing that seems to be different with a "full" for BackupPC is
the "--ignore-times" option.  I found some details on line:240 in
lib/BackupPC/Xfer/Rsync.pm:

        # A full dump is implemented with --ignore-times: this causes all
        # files to be checksummed, even if the attributes are the same.
        # That way all the file contents are checked, but you get all
        # the efficiencies of rsync: only files deltas need to be
        # transferred, even though it is a full dump.

In case you don't know, normally rsync only verifies that the last file
modification time and file size matches-up.  If so, it SHOULD be the same file.
 In reality, there are a couple ways an advanced program could modify a file
without changing those, and more than that, there's always the risk of
file-system corruption.  

In short, a full backup will take longer, but shouldn't transfer any more data
over the network.  

Personally, I'd be inclined to set "RsyncCsumCacheVerifyProb" a little higher
than the default, and NEVER do a full rsync.

However, I'm just getting started with BackupPC myself, so I'm not sure if
BackupPC properly understands that rsync incrementals are just as good as full
backups, and that it can therefore expire the most recent "full" even though no
new "full" backup has been performed.  If it doesn't, that's quite an
unfortunate and unnecessary (legacy) restriction, wasting disk space and
limiting our flexibility.  I'd be interested if anyone has anything else to add.




------------------------------------------------------------------------------
This SF.net Dev2Dev email is sponsored by:

Show off your parallel programming skills.
Enter the Intel(R) Threading Challenge 2010.
http://p.sf.net/sfu/intel-thread-sfd
_______________________________________________
BackupPC-users mailing list
BackupPC-users AT lists.sourceforge DOT net
List:    https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki:    http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/