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
BackupPC-users AT lists.sourceforge DOT net
List: https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki: http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/
|
