The third-party driver (TPD) coexistence feature of VxVM 4.1 allows I/O that is controlled by third-party multipathing drivers to bypass DMP while retaining the monitoring capabilities of DMP. Provided that a suitable ASL is available, devices that use TPDs can be discovered without requiring you to set up a specification file, or to run a special command. In previous releases, VxVM only supported TPD coexistence if the code of the third-party driver was intrusively modified. The new TPD coexistence feature maintains backward compatibility with such methods, but it also permits coexistence without require any change in a third-party multipathing driver.
See "Displaying information about TPD-controlled devices" on page 131.
In VxVM 4.0, there were two possible ways to configure EMC Symmetrix arrays:
On upgrading a system to VxVM 4.1 or later release, existing EMC PowerPath devices can be discovered by DDL, and configured into DMP as autoconfigured disks with DMP nodes, even if PowerPath is being used to perform multipathing. There is no need to configure such arrays as foreign devices.
Scenarios for using DMP with PowerPath shows the scenarios for using DMP with PowerPath.
If any EMCpower discs are configured as foreign discs, use the
vxddladm rmforeign command to remove the foreign definitions, as shown in this example:
vxddladm rmforeign blockpath=/dev/emcpower10 \
To allow DMP to receive correct enquiry data, the Common Serial Number (C-bit) Symmetrix Director parameter must be set to enabled.