Moving drives to other disk group

[Gustavo S. Chung Sang]

We currently have 2 disk groups on an EVA 4400. This EVA is servicing our Win2008R2 with Hyper-V Cluster.

Disk Group 1 = 22 146GB 15K drives = 6 Vraid5 luns
Disk Group 2 = 28 146GB 15K drives = 16 Vraid5 luns

Two of the luns in Disk Group 1 are not being used (988 GB) so I would like to delete them and move a couple of drives from DG1 to DG2 so I have free space to expand some luns.
What options do I have on moving the drives on Disk Group 1 to Disk Group 2. Does this move required downtime or it can be done online. I believe I can do this without having to change configuration in the fiber switch or presentation of luns to the hosts.

Any thoughts, comments, or suggestions would be greatly appreciated.

[Gustavo S. Chung Sang]

Correction on disk size:
Disk Group 1 = 22 300GB 15K drives = 6 Vraid5 luns
Disk Group 2 = 28 300GB 15K drives = 16 Vraid5 luns

[ColinF]

unpresent luns to be deleted, delete luns, ungroup disks from DG1 and finally group them to DG2. No downtime required, no changes to fabric required.

[Zinky]

It can all be done on line.
Simply delete the 2 VRAID5 vdisks from DG1.
The ungroup the disks (one at a time) from DG1 and group taking care you do not get close to teh DG's ocupancy limits out of the remaining 4 Vdisks.

Then once all the disks have ungrouped, group them to DG2.

FWIW, you should really be better just having one DG commprising of 50 disks.... with double protection. You'll have better performance.

But consolidating the 2 DGs will mean collapsing the VRAID volumes on DG1 and moving them to DG2.... I am not familiar with Win2K8 much if it has mirroring facility which would make your reorgs no downtime.

[Gustavo S. Chung Sang]

I am not sure how this point system works but I give you half of the 10 to each.
The idea behind 2 DG was dev and prod and did not want the dev disk performance to affect the prod disk performance (different spindle).
Thank you for your suggestions and also for confirm this can be done.

[Gustavo S. Chung Sang]

I noticed one of the luns was presented to the cluster so I will need to find from Microsoft support how to unpresent that lun.
Also when I have the space to expand the lun I will have to do additional steps to make sure Windows recognize the new size of the lun.