Tim Connors <tim.w.connors <at> gmail.com> writes: > > On Fri, 18 Dec 2009, Malik Recoing. wrote: > > > I know a file will be skiped if it is present in the previous backup, but > > what > > appens if the file have been backed up for another host ? > > It is required to be uploaded first as otherwise there's nothing to > compare it to (yeah, I know, that's a pain[1]). > > It might theoretically be sufficient to let the remote side calculate a > hash and compare it against the files in the pool with matching hashes, > and then let rsync do full compares against all the matching hashes in the > pool (since hash collisions happen), but I don't believe anyone has tried > to code this up yet, and it would only be of limited uses in systems that > were network bandwidth constrained rather than disk bandwidth constrained.
I'm quite sure it will be an improvement for both. Globaly there will be no overhead. More : the hash calculation will be kind of "clustered" delegating it to the client. The matching of identical hash is anyway done by BackupPC_Link. Thus BackupPC_Link will became pointless in a "rsync-only" configuration. The disk and the network trafic will be reduced as many files won't be transfered at all. If such a feature exists, it will give BackupPC a "magic" touch, backing up a wole tree of well known files in a minute even over a slow network. What a pity I'm not fluent with perl... > [1] I just worked around this myself by copying a large set of files onto > sneakernet (my USB key), copying them onto a directory on the local backup > server, backing that directory up, then moving the corresponding directory > in the backup tree into the previous backup of the remote system, so it > will be picked up and compared against the same files when that remote > system is next backed up. I find out tomorrow whether that actually > worked :) > I tougth of a similar solution. When your client are mostly "full system tree" backups, you may have ready-to-copy backups of the differents OS tree. When a new client is added, you copy the corresponding OS directory as it was the first full backup. Malik. ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ BackupPC-users mailing list [email protected] List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
