You can add the 2 disks and the array will restripe the existing LUNs across all 8 disks. You may need to defragment the RAID group after the expansion is complete to ensure that all the free space is in one contiguous block. Once that is complete you can create new LUNs using the free space. The Expansion/Defragmentation priority you set will effect how quickly the process takes and the impact on the array and hosts masked to LUNs within that RAID Group.

The extra space created will be at the end of the raid group (raid 3 raid group expansion is special case). Right click on the Raid Group and select Properties - see the right most tab - this will show you the fragmentation of the RG - if it's real fragmented, you probably want to de-frag the raid group before you expand it - defrag can take a looooooong time. Raid group expansion "can" take a long time also - be careful of the expansion rate you choose - ASAP can have a significate impact on performance.

For general use with LUN Expansion - see the following:

WhitePaper: The Influence of Priorities on CLARiiON LUN Management Operations -Applied Technology

http://powerlink.emc.com/km/live1/en_US/Offering_Technical/White_Paper/H4153-the-influence-of-priorities-on-lun-mgmt-optns-wp.pdf

glen

Perfect!

Thanks to both.

Regards,

Mariano.

1) The fragmentation must be done after or before expand it ? (one said after, other said before)

2) Besides the fragmentation, that I've already unerstood that may take a long time, it's correct that I can do the expand disk while the LUNs are in production, right?

Thanks,

Mariano.

If you do the defrag first, you do it with less disks, if you do after adding in the new disks you'll need to wait for the expansion to complete first, the defrag with more disks, which will take longer.

glen