Craig Barratt wrote: > You're right. > > Each file in the pool is only compressed once, at the current > compression level. Matching pool files is done by comparing > uncompressed file contents, not compressed files. > > It's done this way because compression is typically a lot more > expensive than uncompressing. Changing the compression level > will only apply to new additions to the pool. > > To benchmark compression ratios you could remove all the files > in the pool between runs, but of course you should only do that > on a test setup, not a production installation. > >
I know backuppc will sometimes need to re-transfer a file (for instance, if it is a 2nd copy in another location.) I assume it then re-compresses it on the re-transfer, as my understanding is the compression happens as the file is written to disk.(?) Would it make sense to add to the enhancement request list the ability to replace the existing file in the pool with the new file contents if the newly compressed/transferred file is smaller? I assume this could be done during the pool check at the end of the backup... then if some backups use a higher level of compression, the smallest version of the file is always preferred (ok, usually preferred, because the transfer is avoided with rsync if the file is in the same place as before.) Rich ------------------------------------------------------------------------- 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 [email protected] List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
