clint woodrow wrote:
>
>
> Jeffrey J. Kosowsky wrote:
>> 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.
>
>
> Thanks for the clarification everyone. Of course, what I'd really prefer
> is getting rid of PSTs entirely. When we move up to the next version of
> Exchange, the database size limit will be sufficiently increased (75GB to
> 16TB) so that everyone can move their archives back to the mail server.
> Once that's accomplished, we can just do differentials on the Exchange
> database and the pool impact will be much smaller. We're doing that with
> the existing Exchange backup and the differentials are commonly ~3% of the
> full backup.
>
> BackupPC really is such a great tool, but I suppose it can't do
> everything. I suppose we could have proposed the $30,000 block-level
> backup solution we were shown, but somehow I doubt it would have made it
> through our budget as easily as the free software!
>
I would believe that ZFS will support this.
If you run Backuppc in [Open]Solaris with ZFS as filesystem it should work.
br
Matthias
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