Adding drives to a Dell r720

[smithson83]

I have two Dell R720's acting as hosts for HyperV. I'm starting to begin to run out of space (<25%), ok, so I'm not in any danger at the moment, but I'm looking at options.

 

The drives currently are 10x 300GB 15k SAS in each server, which are still v.expensive. I was thinking of maybe (for roughly the same price per disk) adding a few 900GB 10k SAS drives and creating a separate VD on the controller (Dell's H710mini) and using this purely as a replication store, thus freeing up space on the primary VD.

 

I was wondering if anyone out there who has experience with this server/controller...

 

1) Is this actually possible?

2) Would is slow down the 15k drives sharing the same controller?

 

Any advise would be welcome...