There is no a way for Support to know how long a RAID group defragmentation will take before it is started or to know how much longer it will take to complete. You or Support can make a rough calculation after several LUNs in the RAID group have finished, but that time can vary greatly based on how busy the array is and how busy the RAID group is.
Check the SP event logs for the message "4600 'Defragment' called by ' Navi User." This will mark the start of the defragmentation operation for the RAID group, and then compare the list of LUNs in the RAID group to the following messages in the event logs. examples:
"B 06/29/11 15:24:58 SP B 6f0 Expansion Driver Started [ALU 1109]"
"B 06/30/11 00:06:13 SP B 6f1 Expansion Driver Finished [ALU 1109]"
You can then make a rough calculation, based on the capacity of the LUNs that have finished and the capacity of the LUNs still to go, of how long it will take to finish the entire RAID group.
For more information on this, refer primus solution “emc273316”.