VMS SW raid5 on clustered nodes on ra6400 cards freezing

[CDL_Support]

I have two nodes which are approx 90 miles apart.
1. is an Integrity rx2660 and the other a Alphsa DS15. Both these servers have a smart
array card 6400 installed which has attached to it in the form of storage an MSA30. The disks are configured in raid5 on the card.
2. the two servers are make a cluster running VMS 8.3.
3 Each presented raid 5 device is then shadowed
to each other forming one large volume.
4 Last raid sofware is used to partition up the
shadowed device.

So the probelm that is been seen is that we are
seeing is screen freezes.

A. Is this problem due to the complicated setup with DPA devices on a shadow?
B. The latency between the two sites?
C. The levels complextity of the setup, ie,
to write you commit to the DPA, then the shadow which as tow per for commits to different hosts allowing for latency> Also what times are we tralkign about foa a distance of 90 miles and finally the responce time from a raid5 on an ra6400 card.