Planning for multipath subsystem device drivers

The subsystem device driver (SDD) is a software solution for multiple configuration environments in supported storage resources.

The subsystem device driver is installed on a host system with the native disk-device driver and provides the following functions:
  • Enhanced data availability
  • Dynamic input/output (I/O) load balancing across multiple paths
  • Automatic path failover protection
  • You can download licensed machine code at the same time that applications are running

For the most current support for multipath subsystem device drivers, go to External link icon IBM Spectrum Control - Platform Support: Agents, Servers and Browsers - Multipathing section.

Note:
  1. The AIX® SDD cannot coexist with SDDPCM on the same system.
  2. The Linux® SDD driver is no longer available. Starting with Red Hat® Enterprise Linux 5 and SUSE Linux Enterprise Server 10, only the DM_Multipath is available.
  3. The SDD driver is no longer supported on HP, starting with HP-UX 11i 3 with Itanium®.

For more information about multipath subsystem device drivers, see https://www.ibm.com/support/pages/node/651823.

For more information about how to install, configure, and use the subsystem device drivers, see https://www.ibm.com/support/pages/node/651689.

Upgrading subsystem device drivers

SDD drivers cannot coexist on the same host with the SDDPCM, SDDDSM, or DM_Multiplath drivers. You must upgrade from the existing SDD drivers to the SDDPCM or SDDDSM driver. Part of the upgrade process is to unconfigure and remove all SDD vpath devices. After the upgrade and configuration of the devices, the device names might differ from the previous names. Each device is detected by IBM Spectrum Control as a new device. For information about how to upgrade SDD, see http://www.ibm.com/support/docview.wss?rs=540&context=ST52G7&uid=ssg1S7000303.

Dell EMC PowerPath Multipathing

Dell EMC PowerPath Multipathing supports a wide range of servers including cluster servers connected to Dell EMC storage systems. It tunes your storage area network and selects alternate paths for your data if necessary. It also integrates multiple path I/O capabilities, automatic load balancing, and path failover functions. For more information about Dell EMC PowerPath Multipathing, see http://www.dellemc.com. Search for PowerPath.