Solaris SAN Configuration and Multipathing Guide

Administering Multipathing Devices

Perform the following tasks to administer any multipathing devices.

To Get a List of Multipathing Support That Can Be Administered by the `mpathadm` Command

The multipathing support is identified with the Multipath Management API plug-in library name.

List the multipathing support by typing the mpathadm list mpath-support command.
# mpathadm list mpath-support mpath-support: libmpscsi_vhci.so
(Only one result is shown in the preceding example.)

To Get the Multipathing Support Properties

The multipathing support properties are associated with Multipath Management API plug-in properties.

List the multipathing support by typing the mpathadm list mpath-support command.
# mpathadm list mpath-support mpath-support: libmpscsi_vhci.so
(Only one mpath support name result is shown in the preceding output list example.)

Choose the mpath support name from the output list.

List the multipathing support properties for a specified mpath support name by typing the mpathadm show mpath-support mpath-support-name command.

# mpathadm show mpath-support libmpscsi_vhci.so
mpath-support: libmpscsi_vhci.so
     Vendor: Sun Microsystems
     Driver Name:  scsi_vhci
     Default Load Balance:  round-robin
     Supported Load Balance Types:
          round-robin
          logical-block
     Allows To Activate Target Port Group Access:  yes
     Allows path Override:  no
     Supported Auto Failback Config: yes
     Auto Failback:  on
     Failback Polling Rate (current/max):  0/0
     Supported Auto Probing config: no
     Auto Probing:  NA
     probing Polling Rate (current/max):  NA/NA
     Supported Devices:
          Vendor:  SUN
          Product:  T300
          Revision:
          Supported Load Balance Types:
               round-robin
          Vendor:  SUN
          Product:  T4
          Revision:
          Supported Load Balance Types:
               round-robin

The command output also shows a list of device products that is supported by the multipathing support software. The multipathing support libmpscsi_vhci.so supports T10 target port group compliant devices by default.

To Get a List of Initiator Ports Discovered on the System

An initiator port is part of a path that consists of an initiator port, target port, and a logical unit.

Run the mpathadm list initiator-port command.

# mpathadm list initiator-port
Initiator-Port: iqn.1986-03.com.sun:01:080020b7ac2b.437a3b3e,4000002affff
Initiator-Port: 2000000173018713

To Get the Properties of a Particular Initiator Port

Display the properties of an initiator port by typing the show command.

Run the mpathadm list initiator-port command.

# mpathadm list initiator-port
Initiator-Port: iqn.1986-03.com.sun:01:080020b7ac2b.437a3b3e,4000002affff
Initiator-Port: 2000000173018713

Select an initiator port to use from the output.

Run the mpathadm show initiator-port initiator-port-name command.

# mpathadm show initiator-port 2000000173018713
initiator-port: 2000000173018713
    Transport Type: Fibre Channel
    OS Device File: /devices/pci@1f,2000/SUNW,glc@4/fp@0,0

To Get a List of Logical Units Discovered on the System

The mpathadm list lu command displays the list of logical units attached to the initiator. This list displays the number of paths and the operational path count to each logical unit listed.

Run the mpathadm list lu command.

# mpathadm list lu
    /dev/rdsk/c4t60020F20000035AF4267CCCB0002CEE2d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
        Total Path Count: 2
        Operational Path Count: 2

To Get the Properties and Associated Path Information of a Particular Logical Unit by Name

Display the list of logical units, along with the properties for each logical unit through the mpathadm command. The list of logical units contains logical unit names that in turn can be used to display the properties of a particular logical unit.

Run the mpathadm list lu command.

# mpathadm list lu
    /dev/rdsk/c4t60020F20000035AF4267CCCB0002CEE2d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
        Total Path Count: 2
        Operational Path Count: 2

Select a logical unit name from the output.

Run the mpathadm show lu logical-unit-name command.

# mpathadm show lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
logical unit: /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
    mpath-support libmpscsi_vhci.so
     Vendor:  SUN
     Product:  T4
     Revision:  0301
     Name Type:  SCSI Inquiry VPD page 83 type 3
    Name:  60003ba27d2120004204ac2b000dab00
     Asymmetric:  yes
     Current Load Balance:  round-robin
     Logical Unit Group ID:  NA
     Auto Failback:  on
     Auto Probing:  NA

     Paths:
          Initiator Port Name:  2000000173818713
          Target Port Name:  20030003ba27d212
          Override Path:  NA
          Path State:  OK
          Disabled:  no

         Initiator Port Name:  2000000173018713
          Target Port Name:  20030003ba27d095
          Override path:  NA
          Path State:  OK
          Disabled:  no

     Target Port Groups:
          ID:  2
          Explicit Failover:  yes
          Access State:  standby
          Target Ports:
               Name:  20030003ba27d212
               Relative ID:  0
    
          ID:  5
          Explicit Failover:  yes
          Access State:  active
          Target Ports:
               Name:  20030003ba27d095
          Relative ID:  0

To List All Logical Units Associated With a Particular Target Port

To list paths through a target port use the show command of a logical unit. First, retrieve the list of target ports associated with a logical unit. Then, use the target port to list all logical units associated with this target port.

Run the mpathadm list lu command.

# mpathadm list lu
    /dev/rdsk/c4t60020F20000035AF4267CCCB0002CEE2d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
        Total Path Count: 2
        Operational Path Count: 2

Select a logical unit name from the output.

Run the mpathadm show lu command.

# mpathadm show lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
logical unit: /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
    mpath-support libmpscsi_vhci.so
     Vendor:  SUN
     Product:  T4
     Revision:  0301
     Name Type:  SCSI Inquiry VPD page 83 type 3
    Name:  60003ba27d2120004204ac2b000dab00
     Asymmetric:  yes
     Current Load Balance:  round-robin
     Logical Unit Group ID:  NA
     Auto Failback:  on
     Auto Probing:  NA

     Paths:
          Initiator Port Name:  2000000173818713
          Target Port Name:  20030003ba27d212
          Override Path:  NA
          Path State:  OK
          Disabled:  no

         Initiator Port Name:  2000000173018713
          Target Port Name:  20030003ba27d095
          Override path:  NA
          Path State:  OK
          Disabled:  no

     Target Port Groups:
          ID:  2
          Explicit Failover:  yes
          Access State:  standby
          Target Ports:
               Name:  20030003ba27d212
               Relative ID:  0
    
          ID:  5
          Explicit Failover:  yes
          Access State:  active
          Target Ports:
               Name:  20030003ba27d095
          Relative ID:  0

Select a target port from the output list.

Run the mpathadm list lu -t command.

# mpathadm list lu -t 20030003ba27d212
     /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
          Total Path Count: 2
          Operational Path Count: 2
     /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
          Total Path Count: 2
          Operational Path Count: 2

To List a Logical Unit With a Particular Name Derived From the Hardware Used by the System

Run the mpathadm list lu command.

# mpathadm list lu
    /dev/rdsk/c4t60020F20000035AF4267CCCB0002CEE2d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
        Total Path Count: 2
        Operational Path Count: 2

Select a logical unit name from the output.

Run the mpathadm show lu logical-unit-name command.

# mpathadm show lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
logical unit: /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
    mpath-support libmpscsi_vhci.so
     Vendor:  SUN
     Product:  T4
     Revision:  0301
     Name Type:  SCSI Inquiry VPD page 83 type 3
    Name:  60003ba27d2120004204ac2b000dab00
     Asymmetric:  yes
     Current Load Balance:  round-robin
     Logical Unit Group ID:  NA
     Auto Failback:  on
     Auto Probing:  NA

     Paths:
          Initiator Port Name:  2000000173818713
          Target Port Name:  20030003ba27d212
          Override Path:  NA
          Path State:  OK
          Disabled:  no

         Initiator Port Name:  2000000173018713
          Target Port Name:  20030003ba27d095
          Override path:  NA
          Path State:  OK
          Disabled:  no

     Target Port Groups:
          ID:  2
          Explicit Failover:  yes
          Access State:  standby
          Target Ports:
               Name:  20030003ba27d212
               Relative ID:  0
    
          ID:  5
          Explicit Failover:  yes
          Access State:  active
          Target Ports:
               Name:  20030003ba27d095
          Relative ID:  0

Select an inquiry-string-name from the output.

Run the mpathadm list Lu -n inquiry-string-name command.

# mpathadm list lu -n 60003ba27d2120004204ac2b000dab00
mpath-support: libmpscsi_vhci.so
     /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
          Total Path Count: 2
          Operational Path Count: 2

To Configure Auto-Failback for a Particular Multipathing Support

Symmetrical devices allow for automatic failback to a possible optimal path. If a failover occurs on the initial path, the standby path becomes the new online path. Usually the standby path is a suboptimal path. When auto-failback is enabled, the initial path comes back online, failover to the initial path automatically occurs.

Run the mpathadm list mpath-support command.

# mpathadm list mpath-support
mpath-support: libmpscsi_vhci.so

Select an mpath support name from the output list.

Run the mpathadm modify mpath-support -a [on | off] mpath-support-name command.
# mpathadm modify mpath-support -a off libmpscsi_vhci.so

Run the mpathadm show mpath-support mpath-support-name command to check the change.

# mpathadm show mpath-support libmpscsi_vhci.so
mpath-support: libmpscsi_vhci.so
     Vendor: Sun Microsystems
     Driver Name:  scsi_vhci
     Default Load Balance:  round-robin
     Supported Load Balance Types:
          round-robin
          logical-block
     Allows To Activate Target Port Group Access:  yes
     Allows path Override:  no
     Supported Auto Failback Config: yes
     Auto Failback:  on
     Failback Polling Rate (current/max):  0/0
     Supported Auto Probing config: no
     Auto Probing:  NA
     probing Polling Rate (current/max):  NA/NA
     Supported Devices:
          Vendor:  SUN
          Product:  T300
          Revision:
          Supported Load Balance Types:
               round-robin
          Vendor:  SUN
          Product:  T4
          Revision:
          Supported Load Balance Types:
               round-robin

Note –

The auto-failback display initiated by the mpathadm modify command setting is effective while the system is running. However, to keep the changed setting persistent, you must update the /kernel/drv/scsi_vhci.conf file. Refer to Configuring Automatic Failback.

To Fail Over a Logical Unit

This operation is applicable only to devices in the following two categories:

Asymmetric devices with a proprietary failover mechanism recognized and supported by multipathing support
Devices conforming to the T10 Standard Target Port Group Support libmpscsi_vhci.so and providing explicit mode asymmetric logical unit access

Run the mpathadm list lu command.

# mpathadm list lu
    /dev/rdsk/c4t60020F20000035AF4267CCCB0002CEE2d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
        Total Path Count: 2
        Operational Path Count: 2

Select a logical unit name from the output.

Run the mpathadm show lu logical-unit-name command.

# mpathadm show lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
logical unit: /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
    mpath-support libmpscsi_vhci.so
     Vendor:  SUN
     Product:  T4
     Revision:  0301
     Name Type:  SCSI Inquiry VPD page 83 type 3
    Name:  60003ba27d2120004204ac2b000dab00
     Asymmetric:  yes
     Current Load Balance:  round-robin
     Logical Unit Group ID:  NA
     Auto Failback:  on
     Auto Probing:  NA

     Paths:
          Initiator Port Name:  2000000173818713
          Target Port Name:  20030003ba27d212
          Override Path:  NA
          Path State:  OK
          Disabled:  no

         Initiator Port Name:  2000000173018713
          Target Port Name:  20030003ba27d095
          Override path:  NA
          Path State:  OK
          Disabled:  no

     Target Port Groups:
          ID:  2
          Explicit Failover:  yes
          Access State:  standby
          Target Ports:
               Name:  20030003ba27d212
               Relative ID:  0
    
          ID:  5
          Explicit Failover:  yes
          Access State:  active
          Target Ports:
               Name:  20030003ba27d095
          Relative ID:  0

Run the mpathadm failover lu logical-unit-name command.
# mpathadm failover lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
If this operation is successful, the access state of the devices’ target port groups changes as a result of the logical unit failover.

Run the mpathadm show lu logical-unit-name command to verify the access state change.

# mpathadm show lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
logical unit: /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
    mpath-support libmpscsi_vhci.so
     Vendor:  SUN
     Product:  T4
     Revision:  0301
     Name Type:  SCSI Inquiry VPD page 83 type 3
    Name:  60003ba27d2120004204ac2b000dab00
     Asymmetric:  yes
     Current Load Balance:  round-robin
     Logical Unit Group ID:  NA
     Auto Failback:  on
     Auto Probing:  NA

     Paths:
          Initiator Port Name:  2000000173818713
          Target Port Name:  20030003ba27d212
          Override Path:  NA
          Path State:  OK
          Disabled:  no

         Initiator Port Name:  2000000173018713
          Target Port Name:  20030003ba27d095
          Override path:  NA
          Path State:  OK
          Disabled:  no

     Target Port Groups:
          ID:  2
          Explicit Failover:  yes
          Access State: active
          Target Ports:
               Name:  20030003ba27d212
               Relative ID:  0
    
          ID:  5
          Explicit Failover:  yes
          Access State: standby
          Target Ports:
               Name:  20030003ba27d095
          Relative ID:  0

To Enable a Path

If the path to a logical unit is disabled, the enable command changes the path back to enabled. The full path must be specified using the initiator port name, target port name, and the logical unit. To verify the change, run the show command for the logical unit.

Run the mpathadm list lu command.

# mpathadm list lu
    /dev/rdsk/c4t60020F20000035AF4267CCCB0002CEE2d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
        Total Path Count: 2
        Operational Path Count: 2

Select a logical unit name from the output.

Run the mpathadm show lu logical-unit-name command.

# mpathadm show lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
logical unit: /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
    mpath-support libmpscsi_vhci.so
     Vendor:  SUN
     Product:  T4
     Revision:  0301
     Name Type:  SCSI Inquiry VPD page 83 type 3
    Name:  60003ba27d2120004204ac2b000dab00
     Asymmetric:  yes
     Current Load Balance:  round-robin
     Logical Unit Group ID:  NA
     Auto Failback:  on
     Auto Probing:  NA

     Paths:
          Initiator Port Name:  2000000173818713
          Target Port Name:  20030003ba27d212
          Override Path:  NA
          Path State:  OK
          Disabled:  no

         Initiator Port Name:  2000000173018713
          Target Port Name:  20030003ba27d095
          Override path:  NA
          Path State:  OK
          Disabled:  no

     Target Port Groups:
          ID:  2
          Explicit Failover:  yes
          Access State:  standby
          Target Ports:
               Name:  20030003ba27d212
               Relative ID:  0
    
          ID:  5
          Explicit Failover:  yes
          Access State:  active
          Target Ports:
               Name:  20030003ba27d095
          Relative ID:  0

Select an initiator port and a target port name.

Run the mpathadm enable path -i initiator-port-name -t target-port-name -l logical-unit-name command.

# mpathadm enable path -i 2000000173018713 -t 20030003ba27d095 \
        -l /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2

To Disable a Path

This operation makes the path unavailable for the logical unit, regardless of its operational state.

Note –

The disabled state is not persistent across rebooting. If the path is operational before the next boot sequence, it is enabled by default. This operation is not allowed when the given path is the last operational path remaining.

Run the mpathadm list lu command.

# mpathadm list lu
    /dev/rdsk/c4t60020F20000035AF4267CCCB0002CEE2d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
        Total Path Count: 2
        Operational Path Count: 2
    /dev/rdsk/c4t60003BA27D2120004204AC1A000F1D6Cd0s2
        Total Path Count: 2
        Operational Path Count: 2

Select a logical unit name from the output.

Run the mpathadm show lu logical-unit-name command.

# mpathadm show lu /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
logical unit: /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2
    mpath-support libmpscsi_vhci.so
     Vendor:  SUN
     Product:  T4
     Revision:  0301
     Name Type:  SCSI Inquiry VPD page 83 type 3
    Name:  60003ba27d2120004204ac2b000dab00
     Asymmetric:  yes
     Current Load Balance:  round-robin
     Logical Unit Group ID:  NA
     Auto Failback:  on
     Auto Probing:  NA

     Paths:
          Initiator Port Name:  2000000173818713
          Target Port Name:  20030003ba27d212
          Override Path:  NA
          Path State:  OK
          Disabled:  no

         Initiator Port Name:  2000000173018713
          Target Port Name:  20030003ba27d095
          Override path:  NA
          Path State:  OK
          Disabled:  no

     Target Port Groups:
          ID:  2
          Explicit Failover:  yes
          Access State:  standby
          Target Ports:
               Name:  20030003ba27d212
               Relative ID:  0
    
          ID:  5
          Explicit Failover:  yes
          Access State:  active
          Target Ports:
               Name:  20030003ba27d095
          Relative ID:  0

Select an initiator port and a target port name.

Run the mpathadm disable path -i initiator-port-name -t target-port-name -l logical-unit-name command.

# mpathadm disable path -i 2000000173018713 -t 20030003ba27d095
 -l /dev/rdsk/c4t60003BA27D2120004204AC2B000DAB00d0s2

Administering Multipathing Devices

To Get a List of Multipathing Support That Can Be Administered by the mpathadm Command

To Get the Multipathing Support Properties

To Get a List of Initiator Ports Discovered on the System

To Get the Properties of a Particular Initiator Port

To Get a List of Logical Units Discovered on the System

To Get the Properties and Associated Path Information of a Particular Logical Unit by Name

To List All Logical Units Associated With a Particular Target Port

To List a Logical Unit With a Particular Name Derived From the Hardware Used by the System

To Configure Auto-Failback for a Particular Multipathing Support

To Fail Over a Logical Unit

To Enable a Path

To Disable a Path

To Get a List of Multipathing Support That Can Be Administered by the `mpathadm` Command