From: Craig B. <cba...@us...> - 2007-09-24 07:38:47
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Carl Soderstrom writes: > On 09/09 06:11 , Craig Barratt wrote: > > Rob writes: > > > I just noticed the $Conf{IncrLevels} setting. I'm using rsync and > > > rsyncd as my transport, and I'd like to minimize my network usage since > > > I'm backing up over the internet. I don't care about disk or cpu usage. > > > > > > Does setting: > > > $Conf{IncrLevels} = [1, 2, 3, 4, 5, 6]; > > > do anything to reduce my network usage? Or does rsync and the pooling > > > mechanism already take care of that "behind the scenes". > > > > Yes, it will reduce the network usage. In 3.x each incremental depends > > on the backup of the next lower level, so this means a new file that > > appears after the last full will only be transferred once. > > > > Craig > > Is there any reason for this not to be set, or even to be the default? The only drawback with using $Conf{IncrLevels} is there could be a performance penalty. With a sequence of $Conf{IncrLevels}, all of these backups need to be merged to get the baseline "view' used as the starting point for each new backup. In many cases this could be a worthwhile tradeoff, since re-transferring large new files likely takes more time than merging each backup level. There isn't a performance difference with $Conf{IncrLevels} for tar or smbclient, since just an mtime is used as a reference. Craig |