Adam Goryachev wrote at about 13:42:41 +1000 on Wednesday, June 3, 2009: > clint woodrow wrote: > > > > Matthias Meyer wrote: > >> rsync(d) transmit only changed parts of a file > >> (http://www.samba.org/rsync). e.g. a 2.6 GB mailbox.pst and receive > >> one new mail at sunday. rsync will only transmit this one new mail. > >> > >> > >> And you need a client on windows side. You can use cwRsync or rsync > >> within a cygwin environment. > >> > >> br Matthias > > > > > > Thanks for the details Matthias. I was wondering if one of you could > > confirm something else for me. We've been testing BackupPC for the > > last few months. The local backup server is up and running great and > > we're getting ready to put up an offsite backup server for redundancy > > and offsite security. > > > > Up to this point, I've assumed I wouldn't be able to roll PSTs into > > the backups because they'd be too large to send over the limited > > bandwidth every night and that they'd take too much space in the > > pool. From what Matthias has said, it looks like as long as we have > > the initial backup, subsequent backups shouldn't take nearly as long > > since rsync is sending changes only. Can I also take from this that > > BackupPC won't be storing full copies for every backup? i.e. If the > > user has a 1 GB pst and adds one message of 2k, the pool requirements > > are only 1 GB + 2k, not 2 GB + 2k? > > No, rsync handles the transfer, so you will only transfer > (approximately) 2k for the changes. (Obviously there are additional > overheads for the non-changed sections, but they are very small). > However, once backuppc has the whole new version of the file, it will > add this 1.002G file to the pool, so the pool will consume 2G + 2k. Of > course, if you use compression, then the size of the cpool will be > smaller depending on how compressible your pst files are. > Said another way, BackupPC only does pooling and de-duplication at the file level. To get the "1GB + 2k" you would need to pool at the block level. Such block-level de-duplication would be nice for files that grow such as log files or Inboxes, but it is not possible now with BackupPC.
------------------------------------------------------------------------------ OpenSolaris 2009.06 is a cutting edge operating system for enterprises looking to deploy the next generation of Solaris that includes the latest innovations from Sun and the OpenSource community. Download a copy and enjoy capabilities such as Networking, Storage and Virtualization. Go to: http://p.sf.net/sfu/opensolaris-get _______________________________________________ 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/
