Re: Use SyncIQ to copy data within a cluster.
If you don't want to keep the changes, you should not have to delete the policy, although I don't think this option is in the GUI or if it is, I haven't found it.
So you "allow writes" on the destination C. Then do your testing.
Then when you're ready to go back, try the CLI:
isi sync recovery <policy> --revert
Try this on some test data first, just to be sure. I just did it in my lab. I set up a policy running every 10 mins from Cluster A to Cluster B. Then I set up a second policy to sync locally on cluster B to a different directory. Then under "Local Targets", I selected "Allow Writes". Then I touched a new file. Then on Cluster B I issued the command above. When the job finished, my 2nd copy was r/o again, and my newly touched file was gone.
Like I said, try it on some test data to be sure, but I think this does it.