Hi, Kris Jordan wrote on 30.04.2007 at 17:49:18 [Re: [BackupPC-users] Incremental transferring same data over and over]: > [...] > >> For instance, as a test... > >> > >> 0 full 10min > >> Add a bunch of files. > >> 1 incr 6min > >> 2 incr 6min > >> 3 incr 6min > >> 4 full 0.1min > > ^^^^^^ > > That is surprising. It should take at least 6 minutes (transferring the same > > data as the incrementals). Probably more due to comparing block checksums of > > all unchanged files. > > I have "--checksum-seed" on reducing compare times. > > "same" (from documentation): > > "file is identical to previous backup (contents were checksummed and > verified during full dump)."
hmm, that seems to mean that rsync full backups are done relative to the previous backup (be that full or incremental). Actually, that is quite brilliant. File contents are checked anyway, so why not start with the last state, even if that is not fully trusted? It's even known to be more accurate than the last full, because the only things that might have been missed are changes since the last full ... This would mean that alternating rsync fulls and incrementals would not duplicate any transfers. Nice. The funny thing that this example shows is that rsync fulls *can* be *faster* than an rsync incremental would be in the same situation :-). Regards, Holger ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ BackupPC-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/backuppc-users http://backuppc.sourceforge.net/
