Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

Third-party driver coexistence
The third-party driver (TPD) coexistence feature of VxVM allows I/O that is
controlled by some third-party multi-pathing drivers to bypass DMP while
retaining the monitoring capabilities of DMP. If a suitable ASL is available and
installed, 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. Now, the TPD coexistence feature maintains backward compatibility
with such methods, but it also permits coexistence without requiring any change
in a third-party multi-pathing driver.
See “Changing device naming for TPD-controlled enclosures” on page 104.
How to administer the Device Discovery Layer
The Device Discovery Layer (DDL) allows dynamic addition of disk arrays. DDL
discovers disks and their attributes that are required for VxVM operations.
The DDL is administered using the vxddladm utility to perform the following tasks:
■ List the hierarchy of all the devices discovered by DDL including iSCSI devices.
■ List all the Host Bus Adapters including iSCSI
■ List the ports configured on a Host Bus Adapter
■ List the targets configured from a Host Bus Adapter
■ List the devices configured from a Host Bus Adapter
■ Get or set the iSCSI operational parameters
■ List the types of arrays that are supported.
■ Add support for an array to DDL.
■ Remove support for an array from DDL.
■ List information about excluded disk arrays.
■ List disks that are supported in the DISKS (JBOD) category.
■ Add disks from different vendors to the DISKS category.
■ Remove disks from the DISKS category.
■ Add disks as foreign devices.
The following sections explain these tasks in more detail.
See the vxddladm(1M) manual page.
87Administering disks
Discovering and configuring newly added disk devices