rsync mechanics question

[JamesDR]

JamesDR wrote:
> Tom Riley wrote:
>> Hey All,
>>
>>  
>>
>> I’ve been using rsync (2.6.9) to migrate a 90g message store volume and
>> I’m running into some interesting results. I have two FC storage arrays
>> attached to a Sunfire V280R, running Solaris 8. My 100gig volume is on a
>> Sun StoreEdge 3510, and my new 500gig partition is on an HP EVA.
>>
>>  
>>
>> I used the syntax: rsync -a --stats --delete $SRC/$dir/ $DST/$dir
>>
>>  
>>
>> At present time, the destination volume is 2.5 times the size of the
>> original volume. My first thought was this may be a drive geometry
>> issue, and I’ve been working with Sun to get a solution. They believe
>> rsync is doing a block level copy, instead of a file level copy. That
>> doesn’t seem to jive with what I’ve been reading, but wanted to get some
>> more experienced eyes looking at the problem.
>>
>>  
>>
>> Does rsync copy files at a file copy level or is it attempting to do
>> some block level copying?  Has anyone experienced this sort of bloated
>> expansion of space? Any advice would be greatly appreciated.
>>
>>  
>>
>> -Tom
>>
> 
> It creates temporary files during the xfer then moves them over once
> completed. I think you'll want to use --inplace. So if the store is 90GB
> in size, while the xfer is going on it could be using 180GB +/- (depending.)
> 
> http://rsync.samba.org/ftp/rsync/rsync.html has more info.
> 

Re-reading that, you may want to consider the sync and storage needed
verses network bandwidth. By using --inplace (if I read that right)
you'll be xfering the entire 90GB store over the network. Its a toss up
between network bandwidth (and time to xfer) and storage space.

-- 
Thanks,
James