SA P411 and Windows 2008 MPIO in round robin

[dyera]

Is this supported?

HP DL380 G6 with 2 SA P411 (512MB BBWC) connected to 2 MSA70s with the latest firmware. Obviously the MSA70s also have the dual-domain modules. Cabling is slot #3 port 1 and 2 to each of the MSA port 1's and slot # 2 to each of the MSA's dual domain (2nd) ports.

We are trying to run this with Windows 2008 R2 x64 (all latest patches) and the MPIO feature in Round-Robin mode.

If we attempt to do anything through the Windows Disk Manager, we corrupt the NTFS disks and data or in normal operation get occasional NTFS errors when volume snapshotting occurs. If however we change the MPIO policy to fail-over only, and set the secondary path to standby we are OK. We want to run in the Round-Robin mode for performance reasons.

I should note that all operations performed in the ACU are OK (e.g array creation, logical volume creation, extension etc). It is only actions performed against the OS's NTFS volumes that cause problems.

Server is not yet in production, so alternative configs suggested here can be easily tested.