fs_copy is block level copy so it will copy every single block regardless if there is data or not.

fs_copy is block level copying, but it is smart enough to skip empty blocks

that's interesting, how does it know ? Isn't not smart to know if blocks changed right, otherwise we would not have to use snapshots to perform incremental copies ?

I believe the way it works is that it uses the Smartsnap feature of checkpoints

So it wont copy block that have never been used (written to) before

Its not the same as not copying "empty" blocks or unused blocks - but for a new file system it works out similar so that only the metadata blocks get copied.

Thanks for the info. So, the throughput for the intial fs_copy depends on how much data is there in the file system. I performed couple of tests like

30 gb file system with 2 gb data took 2mins for the intial fs_copy
30 gb file system with 4 gb data took 4 mins.
30 gb file system with 11 gb data took 10 mins for the intial fs_copy.

So, here the throuhput is almost the same. Is there anyway we can increase the throughput for the intial fs_copy. I modified the RCP tcpwindowsize parameter on the data mover which increased the throughput or there any other parameters that we can tune on celerra for better throughput.

Thanks,