In order to do this there may be NO Raid Groups on the first 5 disks. So use LUN migrate to migrate all LUN's from the first 5 disks to other Raid Groups residing on other than the first 5 disks. Make sure there's no Raid Group left on the first 5 disks. Pull one drive out, put the smaller drive in and let the rebuild end. Check the Event Log on BOTH SP's to see whether the rebuild has ended. When the lights on the drives stop blinking this doesn't mean that the rebuild indeed ended. Check these logs !! It takes about 30 minutes for each disk.  Repeat this for each of the other disks. When Navisphere doesn't display the right size, stop navisphere and open it again. The refresh of Navisphere Manager isn't that good, so if you trigger a refresh by actually restarting the GUI, it works fine.
Hi,      I have a CX4-120 with the vault disks being 5 x 15k 300GB FC disks.  If I get 5 x 15k 73 GB FC disks can I do the following:  Replace one 300 GB Vault disk with a 73 GB disk.  Let any rebuild finish. Repeat for each disk. would this work.  Would the resulting Raid Group then decrease in size?  If best practices is to not use the Vault disk for general LUNs, then I'd rather have the FLARE OS (etc) running on the smallest possible disks and use the 300 GB disks for our customers.  thanks in advance,                             David
Replace Vault disks to smaller disks