Timothy J. Massey wrote:
> As BackupPC_tarExtract extracts the files from smbclient or tar, or as > rsync runs, it checks each file in the backup to see if it is identical > to an existing file from any previous backup of any PC. > (http://backuppc.sourceforge.net/faq/BackupPC.html#backuppc_operation) > > This is true for tar-based backups. *Every* incoming file is checked > against the entire pool: "[any] existing file from any previous backup > of any PC." However rsync does *NOT* do this. It checks each incoming > file against a *single* file: the file previously backed up in the > latest next-lowest-level backup. > > If this is incorrect, PLEASE explain to me why. However, if it is not > incorrect, the documentation is incorrect. This is what happens after a new file is transferred by any of the methods including rsync. In addition, the rsync method avoids transferring files and parts of files that already match the previous copy. Rsync can't know what file in the pool to use for the comparison any other way. Even if it computed the hashes remotely, consider what would happen if you had a large backup where the first few bytes of each file were changed before the next run. None of the pool files would match, but by doing the rsync compare against the previous file of the same name, only the first block of each would need to be transferred. -- Les Mikesell [EMAIL PROTECTED] ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/backuppc-users http://backuppc.sourceforge.net/
