Sree, all you need to know about sparing is in this doc,  [URL]
Hi,  Could some one throw some details on the following aspects regarding Deferred Disk Service?  1. Is there any advantage apart from the reduced number of CE visits, which in turn save on cost? 2. DDS is to ensure that the failed spares (??) would be replaced by CE in a bulk.                2.1 Is there a fixed numeric value as to how many drives should fail before the CE replaces them all?                2.2 Is it always true that the CE replaces the drives in bulk when there is just one spare left in the array?                2.3 Is DDS going to take care of the disk technology, or is it just the covering spare count that matters?           3. Would it not be a risk if a particular disk with a specified part number is not available readily, whilst the CE needs to replace the disks in bulk? Is there some mechanism put in place to ensure that this risk is mitigated? 4. Is there any difference between DMX and VMAX in the way the DDS operates? Will VMAX also undergo standard sparing with DDS enabled under any scenario?  Thanks, Sreehari
Deferred Disk Service