On Mon, November 9, 2015 12:42 pm, m.roth at 5-cent.us wrote: > Gordon Messmer wrote: >> On 11/09/2015 09:59 AM, John R Pierce wrote: >>> On 11/9/2015 9:50 AM, Gordon Messmer wrote: >>>> I don't see the distinction you're making. >>> >>> a incremental backup copies everything since the last incremental >>> a differential copies everything since the last full. >> >> I guess that makes sense, but in backup systems based on rsync and hard >> links (such as rsnapshot), *every* backup on the backup volume is a >> "full" backup, so incremental and differential are the same thing. >> >>> rsync is NOT a backup system, its just a incremental file copy >> >> ..which can be used as a component of a backup system, such as rsnapshot >> or backuppc. > > Actually, we use rsync for backups. We have a script that creates a new > daily directory... and uses hard links to previous dates. That way, it > looks like a full b/u... but you can go to a previous date to restore an > older version of the file (aka ACK! I saved that file full of garbage to > my Great American Novel filename! <g>). I wonder how filesystem behaves when almost every file has some 400 hard links to it. (thinking in terms of a year worth of daily backups). Valeri > > And if you aren't familiar with hard links, which rsync happily creates, > they were certainly hard enough to wrap my head around, until I got it... > and really like them. Just note that they *must* be on one filesystem, as > opposed to symlinks, which can cross filesystems. > > mark > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos > ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++