Do you propose to create NEW Storage Types that would work 2 controllers and distribute the virtual machines included on the other backups to one virtual machine?
No, because you only needs to create multible Volumes. How many volumes in total you have already created? You have atleast 2 volumes or more right?
About Double Redundancy. Yes the Storage Vendors suggest to choose RAID6 because of the large drives today and the period of time to rebuild a large drive in case of a failure. During the rebuild there is a change of a double disk failure and when this happends you will loose data.
From the pictures i can see than you run SCOS <= 7.2.x .... i suggest that you call Dell and ask them to schedule a upgrade to > 7.3.x because this release gives up to 40% more performance an more important it introduce the feature of the "distributed spare" instead of a singe dedicated spare. Rebuild times are dramaticly reduced!
How much space are required for all of your VMs? If there is enough space available go for DoubleRedundance if not stay at Single Redundancy
We often choose Singe for our TIER 1 (SSD) and for TIER 3(10K SAS) the Double. Because we dont like to see the waste of Storage for a RAID10 Dual Mirror (again 4x times the amount of storage is needed). But similar to to the other guy we also have often 2 SC and use sync. replication.
Normaly the question about single or double needs to be answered for ordering the system because the Dell Midrange-Sizer returns the usable capacity and the number of needed drives which needs to be specify before buying the array.
How many Backuppoints your BackupExec creates and what are your requirements of holding the savepoint on disk over the time? How likely/often you need to restore single items like Files, SQL Tables or Windows AD objects?
Regards
Joerg