Both are possible, just keep in mind that for SmartPools

all nodes must be on the same IB switch and run exactly the same OneFS release,

as they will form one cluster of course.

makes sense?

-- Peter

You need to be careful here.  If, by "new", you mean X*10 nodes, you'll won't be able to add them to your existing cluster because 6.5 won't support the new hardware.  You'll need to upgrade OneFS first.  SmartPools is a licensed feature but you can do the migration in-place without it if you're patient and can't get a temporary SmartPools license.

SyncIQ requires licenses but you can probably get a temporary license. 

My preference, given that your current installation is ancient (from a OneFS point of view), would be to create a newly configured cluster and migrate the data.  However, this will require an outage to do the final cut-over.

Can you please share some more details about SyncIQ - how does it work.

We have approx 130 TB of data which we have to move to new cluster.

Kindly suggest safer way as data is critical.

Regards,

Bhavesh Rambhia

Excellent introduction to SyncIQ:

https://www.emc.com/collateral/hardware/white-papers/h8224-replication-isilon-synciq-wp.pdf