Rich Rauenzahn wrote: > John Pettitt wrote: >>> >>> >> What happens is the newly transfered file is compared against candidates >> in the pool with the same hash value and if one exists it's just >> linked, The new file is not compressed. It seems to me that if you >> want to change the compression in the pool the way to go is to modify >> the BackupPC_compressPool script which compresses an uncompressed pool >> to instead re-compress a compressed pool. There is some juggling that >> goes on to maintain the correct inode in the pool so all the links >> remain valid and this script already does that. >> >> > You're sure? That isn't my observation. At least with rsync, the > files in the 'new' subdirectory of the backup are already compressed, > and I vaguely recall reading the code and noticing it compresses them > during the transfer (but on the server side as it receives the data). > After the whole rsync session is finished, then the NewFiles hash list > is compared with the pool. Identical files (determined by hash code > of uncompressed data) are then linked to the pool. > > If that is all true, then it seems like there is an opportunity to > compare the size of the existing file in the pool with the new file, > and keep the smaller one. > > Rich
Looking at the code in PoolWrite.pm it seems to do a dance of comparing until it either gets a miss-match in which case it writes a new file or eof in which case it links. I haven't read the rsync code so that may do something different to the tar code ... belay that ... I just looked at RsyncFileIO.pm and it calls PoolWrite to do the file write. John ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
