Multipath Support; Microsoft Mpio; Storage Manager Rdac (Consists Of Microsoft Mpio And Ds3000 Dsm) - IBM DS3000 Introduction And Implementation Manual

7065HostConfig.fm

6.2 Multipath support

If you use two HBAs for attachment to a dual-controller subsystem, you will have to install
multipath support to allow the failover procedures to function. If a controller or path fails, the
host server can continue to access the logical drives through the alternate path.
If you are using the iSCSI software initiator under Windows or Linux with access to more than
one iSCSI port, you will also require to install RDAC/MPP/MPIO.
On Windows Server 2003 hosts, we use Microsoft MPIO for multipath support. On Linux, the
open-source RDAC solution is required. Let's have a closer look at these two
implementations.

6.2.1 Microsoft MPIO

Microsoft MPIO is a framework that provides integration of various storage subsystem
vendors' multipath solutions into the Windows architecture. MPIO usually interacts with a
Device-Specific Module (DSM) which should be provided by the storage subsystem vendor.
The idea is to offer a standardized way for storage vendors to integrate their hardware
solutions with Windows, rather than each vendor having to develop their own proprietary
multipath implementation.
Microsoft MPIO consists of the following three drivers:
mpdev.sys
mpio.sys
mpfltr.sys
As stated above, we also need the DSM which supports DS3000. The DS3000 DSM is
installed as a part of DS3000 Storage Manager host server package.
Figure 6-3 Storage Manager RDAC (consists of Microsoft MPIO and DS3000 DSM)
112
IBM System Storage DS3000: Introduction and Implementation Guide
Draft Document for Review August 30, 2007 12:59 am