m2data wrote:

>>How efficient it will be is just another thing
>
> Yesterday I tried backing up my database and rsyncing it with a 8 days
> old backup. The file was 2.4GB in size and it did the rsync only
> transfering 140MB. It's still alot of data, but it's not bad.

Having only come to rsync in the last day, I think I understand how it
works. It creates a difference file between the source and the
destination and copies ( compressed if selected ) the diff which it then
applies to the destination copy. My understanding of GBAK is a little
more hazy, but I think that it will maintain BLOB data in the same order
between 'runs' so that rsync should not have to coy them.

> What I don't understand is that changing the blocksize to the same
> size as the pagesize gave me the best result? Does gbak backup data i
> chuncks equal to the pagesize of the database?

That would tie in with my comment above. If the data is not being copied
block for block, I can see than rsync would have more trouble with the diff.

>>... In general terms, rsyncing databases is quite unuseful (and
> dangerous some times).
>
> Why is it unuseful? The database contaings PNG/JPG images, which is
> already compressed. I would never be able to compress the file to
> 140MB!
>
> Why is it dangerous?

SINCE you have already run GBAK, and have an 'off line' file I can't see
that it a problem. It WOULD be a problem if trying to do it on the live
database. I think Jaume missed that?

--
Lester Caine
-----------------------------
L.S.Caine Electronic Services