On Wed, Jun 20, 2012 at 10:17 AM, jonas <jonas AT freesources DOT org> wrote:
>
>
> I restarted BackupPC and that way stopped all active full backups.
> After that I started incremental backups for several hosts. And now I
> was really surprised: the incremental backups are much faster than the
> full backups. Even for hosts with 150GB of data, the incremental backup
> (few new files) took just some hours, while the second full backup for
> the same host took days.
>
> Did I get anything wrong? I'm curious to hear your opinions.

The difference is that full rsync backups add the --ignore-times
option and does a full block checksum comparison of all the content.
This does not take a lot of bandwidth but does take the time for the
disk reads.  Incremental runs quickly skip anything where the
timestamps and length match.    If you have checksum caching enabled,
after the 2nd full the server side will not have to read/uncompress
the data of unchanged files but the target system still has to do the
read.  Also, rsync sends the entire directory listing before starting
which might be a problem if your server does not have much RAM or does
many backups concurrently.

-- 
   Les Mikesell
      lesmikesell AT gmail DOT com

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
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/