Rsync 4TB datafiles...?

[Linus Hicks]

Paul Slootman wrote:
> On Tue 21 Mar 2006, lsk wrote:
> 
>> I don't know how it would work if we do rsync with the files--from option ?
> 
> I'm not sure how rsync behaves when confronted with a network problem
> during a session, so I won't give an answer to that.
> However, doing individual files sounds reasonable, so make it a loop:
> 
> < dbf-list while read filename; do rsync -vz $filename destser:$filename done
> 
>> Also rsync gurus would you suggest which is the fastest way to trasfer this
>> 4 TB data ? Any suggestions...would be of great help.
> 
> I'd recommend doing --inplace, as chances are that data won't move
> within a file with oracle data files (so it's not useful to try to find
> moved data), and copying the 4TB to temp. files every time could become
> a big timewaster. Also the -t option could be handy, not all files
> change all the time IIRC.

The above remark about not being "useful to try to find moved data" provoked an 
idea. But my understanding of --inplace is apparently different from yours. I 
thought --inplace only meant that the destination file would be directly 
overwritten, not that it would turn off any of the optimizations for finding 
moved data.

It would be useful (I think) on a fast network to be able to turn off those 
optimizations, and only compare blocks located at the same offset in source and 
destination. If that is not how --inplace works, I wonder if that would be a 
performance win.

Linus