Hi,
I did some benchs as suggested by Cedric.
At first, I rsynced with options rsync -r --ignore-times --stats -h, and then I rsynced with options rsync -rc --stats -h
The total duration of 1st rsync (--ignore-times) for all my tablespaces is 24 min 24 sec.
Please find below details printed by rsync for 1 tablespace (size 107 Go found using du -h) ;
For this tablespace, duration was 17 minutes 20 seconds.
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Mon Nov 21 12:35:56 CET 2011
/var/opt/hosting/db/profiles/profiles/
Number of files: 22468
Number of files transferred: 22464
Total file size: 114.04G bytes
Total transferred file size: 114.04G bytes
Literal data: 243.47K bytes
Matched data: 114.04G bytes
File list size: 416.00K
File list generation time: 0.001 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 74.45M
Total bytes received: 116.52M
sent 74.45M bytes received 116.52M bytes 185.68K bytes/sec
total size is 114.04G speedup is 597.17
Mon Nov 21 12:53:04 CET 2011
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And duration for rsync -rc for all tablespaces is 32 minutes 2 seconds :
Duration for only this tablespace is 21 minutes 41 seconds.
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Mon Nov 21 15:07:57 CET 2011
/var/opt/hosting/db/profiles/profiles/
Number of files: 22468
Number of files transferred: 11
Total file size: 114.04G bytes
Total transferred file size: 50.75M bytes
Literal data: 308.81K bytes
Matched data: 50.44M bytes
File list size: 775.13K
File list generation time: 0.001 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 1.12M
Total bytes received: 55.08K
sent 1.12M bytes received 55.08K bytes 899.32 bytes/sec
total size is 114.04G speedup is 97434.05
Mon Nov 21 15:29:38 CET 2011
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So, it looks that option --ignore-times is helpful.
Thanks for your comments.
Jal