Les Mikesell <[EMAIL PROTECTED]> wrote on 01/26/2007 04:04:43 PM: > Timothy J. Massey wrote: > > It seems to me, then, that the documentation is *wrong*: rsync does not > > compare against the pool, *ever*; only against a previous backup (most > > likely the next-highest backup level, but I have yet to find this > > information yet). > It is not wrong if you take into account the fact that links are just > different names for the same file. RsyncP can only find the existing > match by the mangled names in the previous full because it doesn't have > access to enough data to recompute the hash of the pool file. However > the files that match, being hardlinks, are actually the same file that > is in the pool and RsyncP can uncompress that to do the rsync > block-compare algorithm with a stock rsync on the other end.
That is true. But that is *not* what the documentation says. Here is a direct quote: 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. Tim Massey If a > difference is found, it must construct a new file (as would rsync) with > the existing parts from the old file and the differences from the new, > then link that in as a new file. > > -- > 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/
