rsync - Mar 2008 - PST Rsync Issues

Hi All,

I have a 1.8GB PST file that is backed up every night from a cygwin install)
and every night rsync transfers about 1.8GB of data for that file. It
changes a bit, but for all intents and purposes the entire file is
transferred. There are other files on this system that rsync more typically,
so I'm fairly certain this isn't a switch or command error on the
calling
end. I have also verified that the PST is closed at the time of backup.

I'm curious if PSTs are just un-rsyncable due to their makeup or if there is
something I can do to pare down this transfer and subsequent storage.

Any tips or ideas are welcome.

Thanks,

Jon
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Jon Watson wrote:
>
> I'm curious if PSTs are just un-rsyncable due to their makeup or if 
> there is something I can do to pare down this transfer and subsequent 
> storage.
>
> Any tips or ideas are welcome.
Outlook PST files are effectively database files. They can be optionally 
compressed and encrypted. If either of these options are enabled, I'd 
say it would completely screw up rsync's potential to do a differential 
copy - i.e. you'd transfer the lot every time. Even if those options 
aren't enabled, it could be that the data is altered dramatically each 
time a change in Outlook occurs that it still screws up rsync.

Basically PST (and OST) files don't play nicely with differential copy 
tools. Similarly, the new Office 2007 format (basically compressed XML 
files) and OpenOffice format won't play nicely either - as compressed == 
random data - and rsync won't see linear changes in them like it can in 
text files/etc.

(hope there's nothing too incorrect in the above. I'm sure someone will 
shout at me if I'm wrong ;-)

-- 
Cheers

Jason Haar
Information Security Manager, Trimble Navigation Ltd.
Phone: +64 3 9635 377 Fax: +64 3 9635 417
PGP Fingerprint: 7A2E 0407 C9A6 CAF6 2B9F 8422 C063 5EBB FE1D 66D1