HPUX : THE AUTO PATH COMMAND-LINE INTERFACE (CLI)

HP Auto Path provides automatic input/output (I/O) path failover, failback,

recovery, and load balancing for host systems configured with multiple host adapters and connections to a disk array.Auto Path provides enhanced data availability with these features:

• automatic path failover to an alternate path

• automatic path recovery after failed path is serviced 

• automatic failback when a path recovers from failure

• dynamic load-balancing over multiple paths

• command-line user interface (CLI) for Auto Path management

• ability to reestablish previous load-balancing policy after reboot


autopath - Secure Path Management Utility.

 DESCRIPTION
      Secure Path product provides the interface to manage and retrieve
      information about the devices that belong to the supported HP
      StorageWorks Active-Active disk arrays.

      autopath is a management utility that provides a command line user
      interface to monitor and manage devices, storage systems, and paths to
      units that belong to the supported HP StorageWorks Active-Active disk
      arrays. Autopath interacts with the 'hpap' Secure Path driver for
      performing these tasks.

      The autopath utility:

      + displays device information including the alternative paths to end
      LUN

      + includes or excludes supported active-active disk arrays from Secure
      Path control

      + includes or excludes supported active-active disk array types from
      Secure Path control

      + adds or deletes devices from Secure Path control

      + restores device paths after their recovery from failures

      + sets options such as load balancing, preferred path and infinite
      retry for supported devices.

      + preserves the array and lun specific persistance settings across
      reboots

      + discovers devices added online

      + sets read optimization for EVA-AA disk array devices. EVA-AA arrays
      include EVA 3000/4000/5000/6000/8000/4100/6100/8100/4400 disk arrays.

      + enables or disables proactive path monitoring for faster recognition
      of failed and recovered paths

      + creates and manages virtual device special files for all Secure Path
      devies
 

through the CLI

The HP Auto Path software performs dynamic load balancing of data flow

through multiple paths. It detects multiple paths to each logical device and

distributes the data load among the paths for optimum performance.

The user interface lets a system administrator define load balancing policies

and preferred paths, and view device path information. Auto Path manages

paths according to the balancing policy, ensuring that no single path is a

performance bottleneck.

The Auto Path command-line interface (CLI) can be used only on hosts

connected to devices with the Auto Path driver installed. The commands

supported by this interface and the syntax are described here:

• autopath display

• autopath help

• autopath recover

• autopath retrieve

• autopath set_lbpolicy

• autopath set_prefpath

 Syntax autopath set_lbpolicy policy path

policy The load balance policy name:

NLB no load balance policy

RR round robin

SQL shortest queue length

SST shortest service time

path The physical device path.

Description The autopath set_lbpolicy command sets the load balance policy for the

specified device path.

Example HP $ autopath set_lbpolicy RR /dev/dsk/c0t0d0

autopath: Load Balance Policy set successfully for /dev/dsk/c0t0d0