you can run step 2 as many times as you like. I had to migrate a couple of LUNs that were used for Oracle dump area, they were 1TB in size. I ran my initial copy during the day (since these LUNs were mostly used at night), i set throttle relatively low as not to impact overall array performance and then i would run multiple incremental's until the final day of cut-over. Data on the target will be "crash consistent" because your host is still up and running.  It will be truly consistent when you shutdown the host and perform your last incremental copy.  San Copy utilizes "tracking" bitmap (saved in RLP)  to track changes between updates, i am not aware how to get "delta" information from that bitmap.
 We are planning to migrate 5 TB of data from one clariion to another clariion using SAN Copy. The host is VMware and needs to be online during the Migration. So for sucessfull migration can i follow these steps  1) Validate the Zones and Connections between the two clariions 2) Configure the reserved lun pool ( 20% of the source lun). 3) create the San copy session using incremtanl option 4) wait till 100 % data is copied to the destination lun 5) during the final cutover shutdown the VMware hosts and run again the incremental session again . 6) Copy done.  Please clarify are these steps good for an online incremental SAN copy session. If yes can any one tell me difference in step 3 and step 5. Do we use different commands or just use the same commands for step 3 and step 5. Please correct me if anything is missing.
SAN Copy /Incremental