I am using ESXi 5.1 free and have installed a second RAID set. The first set was running out of space. What I would like to do is separate the OS's of multiple servers from their data. I'd like to use the new RAID set for OS's and the old for data. Is there a simple way to move the OS partitions only to the new RAID set?
With the VMs you should be able to cold migrate the VM which will as I recall will allow you to seperate the virtual disks -
Please do a V2V conversion of the VM or storage vMotion Advanced option as per the requirement above.
I'm assuming this new RAID set is local storage on the ESXi free host? If so, as weinstein5 said, you would need to do a cold migration of the VMDK's you'd like to host on the new storage pool (RAID set). Detach the data VMDK from the VM, manually move it over to the new datastore, the re-attach.