Data Backup and Recovery

DSM for Windows MPIO and iSCSI


We have a customer condering SnapManager for Exchange, which will require SnapDrive for Windows. They will be using iSCSI protocol for data access. I realize that for multipathing on the Windows hosts, the customer could use Microsoft's multipathing, but from the reading I do, it seems like NetApp DSM for Windows MPIO will be a more robust solution. My questions are:

1) Does the NetApp DSM software include both FC and iSCSI drivers?

2) Does installing SnapDrive require multipathing on the host? (my understanding is that it does)

3) Does the SnapDrive software include the NetApp DSM software or does it need to be licensed separately

Thank you.




Hi, Tom.

For (1), NetApp's most recent MPIO DSM 3.2R1 package supports FCP and iSCSI.

For (2), SnapDrive itself doesn't require MPIO on the host. A Windows server could use SnapDrive over a single iSCSI/FCP connection to a NetApp controller without MPIO. If you are implementing a production configuration, however, multipathing (MPIO, MCS, etc.) should be a part of the solution. I would strongly recommend reading TR3441 for multipathing possibilities. Since you mentioned SnapManager for Exchange (SME), you will need SnapDrive, the Windows Host Utilities Kit and some form of multipathing.

For (3), the NetApp DSM was included as a separate licensed feature in older SnapDrive (before 4.2) packages for both iSCSI and FCP environments. As of SnapDrive 4.2 and later, the NetApp DSM was separated out of SnapDrive into its own licensed package.


We have iSCSI running with the MS MPIO and have no problems to report.


So...I was going to be lazy and ask if anyone could summarize the difference/benefits between NetApp MPIO and MS MPIO....but then I found this.

I'd be curious if anyone cares to add to that or has found MS's MPIO lacking overall (given being free it can be hard to advocate for NetApp's MPIO given the cost).


I think you can also create FC and iSCSI paths to the same LUN with the ONTAP DSM.