The Subsystem Device Driver is a pseudo device driver designed to support the multipath configuration environments in the IBM TotalStorage Enterprise Storage Server, the IBM TotalStorage DS family, the IBM SystemStorage SAN Volume Controller, and IBM BladeCenter S SAS RAID Controller. It resides in a host system with the native disk device driver and provides the following functions:

- Enhanced data availability
- Dynamic I/O load-balancing across multiple paths
- Automatic path failover protection
- Concurrent download of licensed internal code
- Path-selection policies for the host system

Please see the Multipath Subsystem Device Driver User's Guide under "Installation Instructions" for any additional prerequisite information.

See the "Subsystem Device Driver User's Guide" for installation and usage information.

See the "Readme" file below for information regarding defects and fixes that are associated with this level of SDD code.

See the "SDD Flash Documents" for any post-release, critical product information.

Refer to the "Support Matrix for Subsystem Device Driver (SDD), Subsystem Device Driver Path Control Module (SDDPCM), and Subsystem Device Driver Device Specific Module (SDDDSM)" and the corresponding storage interoperability matrix to determine the support level for your configuration.

Consult the README for a list of supported kernel levels, but also note the following additional restrictions:

SVC: For SLES 9, IBM does not support the 2.6.5-7.257 kernel and recommends using the 2.6.5-7.267 kernel instead.

DS8000/ESS: For SLES 9, only kernel levels 2.6.5-7.193 and later are supported. For SLES 8, the only supported levels are 2.4.21-278, 2.4.21-295, 2.4.21-304, 2.4.21-306, and 2.4.21-309.

DS6000: For SLES 9, only kernel levels 2.6.5-7.193 or 2.6.5-7.267 and later are supported. For SLES 8, the only supported levels are 2.4.21-278, 2.4.21-295, 2.4.21-304, 2.4.21-306, and 2.4.21-309.

Note: For Linux Device Mapper Multipath support, refer to the respective storage interoperability matrix web links on top of the page for the supported DM, DM module version, and host architecture (x86, ppc, x86_64).

Warning: Before setting up the remote/SAN boot on SLES9 PowerPC, read the important documentation in the Multipath Subsystem Device Driver User's Guide.

SDD Package for SAN Volume Controller (SVC)

SDD Package for ESS

SDD Package for DS6000

SDD Package for DS8000

Device Mapper Multipath Configuration File for ESS, DS6000, DS8000 and SVC

Device Mapper Multipath Configuration File for RSSM
Previous Subsystem Device Driver Releases

SDD Package for SAN Volume Controller (SVC)

SDD Package for DS8000

DESCRIPTION	DOCUMENTATION	DOWNLOAD	RELEASE DATE
Platform SLES 10	Readme Version 3.01 English Byte Size 10664	Configuration File Version 3.01 For SLES 10 English Byte Size 5650	10/31/08
Platform RHEL 5	Readme Version 3.01 English Byte Size 10664	Configuration File Version 3.01 For RHEL 5 English Byte Size 6352	10/31/08

DESCRIPTION	DOCUMENTATION	DOWNLOAD	RELEASE DATE
Platform SLES 10	Readme Version 3.02 English Byte Size 9635	Configuration File Version 3.02 English Byte Size 5130	07/21/09
Platform RHEL 5	Readme Version 3.02 English Byte Size 9635	Configuration File Version 3.02 English Byte Size 5130	07/21/09