S4k/DS5k and DS8k on VIOS2.1 using SDDPCM V2.2.x - Temporary support solution until end of 2009
SDDPCM version 2.4.x and higher supports DS4k/DS5k devices on AIX. However, SDDPCM is NOT supported on VIOS for DS4k/DS5k at this time. On VIOS2.1 DS4k/DS5k devices are only supported with plain AIX MPIO. SDDPCM support for DS4k/DS5k on VIOS will not be available in the near future and SCORES for this support will be rejected. Furthermore, RDAC is also no longer an option for DS4k devices on VIOS2.1. Only on VIOS1.5 RDAC is still an option and supported for DS4k.
If clients want to use DS8k and DS4k/DS5k on the same VIOS 2.1 partition they cannot install the SDDPCM 2.4.x fileset as this SDDPCM version - once installed - will also use SDDPCM for DS4k/DS5k devices which is currently not supported! On the other hand, DS8k requires at least SDD or SDDPCM to be used, only using plain AIX MPIO for DS8k devices is no option as it is also not supported.
A temporary solution until end of 2009 for clients who want to run DS8k and DS4k/DS5k devices on the same VIOS2.1 partition would be to use a previous version of SDDPCM V2.2.0.4 with the appropriate Host Attachment Script V1.0.0.14 which is still supported for DS8k and does not have any built-in support for DS4k/DS5k devices. Here it is important to use exactly the following filesets:
SDDPCM 2.2.0.4 (devices.sddpcm.61.rte) with
Host Attachment Script (devices.fcp.disk.ibm.mpio.rte) version 1.0.0.14
These fileset versions will ensure that SDDPCM is only used for DS8k devices and not for DS4k/DS5k devices. DS4k/DS5k devices will be handled as plain AIX MPIO devices only.
This is a temporary solution that came up in a discussion with SDD development and the SCORE team. The further plan is to provide AIX APARs by end of 2009 which allow to upgrade to the latest SDDPCM level, and then use "manage_disk_drivers" command to have native AIX PCM to configure DS4/5K devices on the VIO Server. The risk is, customer will miss out on the defect fixes in the latest SDDPCM until end of the year, until they upgrade to the newer SDDPCM level and AIX APAR.
#### UPDATE (January 2010) ####
With the release of AIX 6.1 TL4 and VIOS 2.1.2.10 the manage_disk_drivers command has changed substantially. It now offers a new syntax and more options to configure multipath drivers for XIV, DS3950, DS4100, DS4200, DS4300, DS4500, DS4700, DS4800, DS5100 (including DS5300) and DS5020 storage devices. Supported drivers are SDDPCM (displayed as AIX_SDDAPPCM for DS4k/DS5k/DS3950), AIX native PCM (displayed as AIX_APPCM for DS4k/DS5k/DS3950 as active/passive subsystems or AIX_AAPCM for XIV as active/active subsystem), AIX_non_MPIO (XIV using a third party multipath driver) and RDAC/AIX_FCP array driver (displayed as AIX_fcparray; only supported for DS4K storage subsystems). The new manage_disk_drivers command is supported bySDDPCM 2.5.1.0 (or higher). Unfortunately only SDDPCM 2.5.0.0 is currently supported for DS8000 as latest version at the time of writing (January 2010). When SDDPCM 2.5.1.0 (or higher) will be available for DS8000 it should be possible to have DS8000 and DS4000/DS5000 subsystems attached to the same VIO Server, using SDDPCM for DS8000 devices and native AIX MPIO for DS4000/DS5000 devices in a supported configuration.
Please see the IBM Techdoc TD105433 at http://w3.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/TD105433 for more information about the new manage_disk_driver command and options.
Please note, that this is a statement of direction which is subject to change or withdrawal without notice representing goals and objectives only.
THE INFORMATION PROVIDED IN THIS DOCUMENT IS DISTRIBUTED "AS IS" WITHOUT ANY WARRANTY, EITHER EXPRESS OR IMPLIED.
References:
SDDPCM Support Matrix