The powermt command is a utility that is used to manage and monitor the performance and availability of storage devices in a SAN (Storage Area Network). It is typically used in enterprise environments to manage large storage systems that are accessed by multiple servers.
Below are few of the most commonly used commands to check the POWER PATH config on unix servers.
1. Display High Level HBA I/O Paths
To display a list of all the storage devices that are currently being managed by powermt, use the display subcommand:
# powermt display Symmetrix logical device count=212 CLARiiON logical device count=0 Hitachi logical device count=0 Invista logical device count=0 HP xp logical device count=0 Ess logical device count=0 HP HSx logical device count=0 ============================================================================== ----- Host Bus Adapters --------- ------ I/O Paths ----- ------ Stats ------ ### HW Path Summary Total Dead IO/Sec Q-IOs Errors ============================================================================== 3 0/4/0/0/0/1 optimal 424 0 - 0 848 5 0/5/0/0/0/1 optimal 424 0 - 0 848
2. Display specific LUN
To display the status of a specific storage device, use the display subcommand with the dev= option followed by the device name:
# powermt display dev=emcpowera
When there are multiple LUNs connected to a server, you might want to view information about a specific LUN by providing the logical name of the LUN as shown below.
3. Display All Attached LUNs
Mostly we used to run this command powermt, which will display all the attached logical devices to the server.
# powermt display dev=all Pseudo name=disk915 Symmetrix ID=000290103691 Logical device ID=06B8 state=alive; policy=SymmOpt; priority=0; queued-IOs=0; ============================================================================== --------------- Host --------------- - Stor - -- I/O Path -- -- Stats --- ### HW Path I/O Paths Interf. Mode State Q-IOs Errors ============================================================================== 3 0/4/0/0/0/1.0x5006048c52a862e7.0x40a6000000000000 c14t4d6 FA 8cB active alive 0 2 3 0/4/0/0/0/1.0x5006048c52a862f7.0x40a6000000000000 c15t4d6 FA 8dB active alive 0 2 5 0/5/0/0/0/1.0x5006048c52a862e8.0x40a6000000000000 c16t4d6 FA 9cB active alive 0 2 5 0/5/0/0/0/1.0x5006048c52a862f8.0x40a6000000000000 c17t4d6 FA 9dB active alive 0 2 Pseudo name=disk988 Symmetrix ID=000290103691 Logical device ID=074B state=alive; policy=SymmOpt; priority=0; queued-IOs=0; ============================================================================== --------------- Host --------------- - Stor - -- I/O Path -- -- Stats --- ### HW Path I/O Paths Interf. Mode State Q-IOs Errors ============================================================================== 5 0/5/0/0/0/1.0x5006048c52a862e8.0x40dc000000000000 c16t11d4 FA 9cB active alive 0 2 3 0/4/0/0/0/1.0x5006048c52a862e7.0x40dc000000000000 c14t11d4 FA 8cB active alive 0 2 3 0/4/0/0/0/1.0x5006048c52a862f7.0x40ce000000000000 c15t9d6 FA 8dB active alive 0 2 5 0/5/0/0/0/1.0x5006048c52a862f8.0x40ce000000000000 c17t9d6 FA 9dB active alive 0 2 Details: a. Pseudo name=emcpowera – The device name that can be used by the server. For example, /dev/emcpowera. b. CLARiiON ID=AAA00000000000 [dev-server] - EMC CLARiiON CX3 serial number and the server name. c. Logical device ID=11111111 [LUN 1] – LUN number. For example, LUN 1. d. state=alive; policy=CLAROpt; – This displays that this particular LUN is valid and using the CLAROpt policy. e. Owner: default=SP B, current=SP B – This indicates that the default (and current) owner for this LUN is storage processor SP B.
4. powermt check_registration – Display PowerPath Registration Key / Status
If you’ve lost the PowerPath registration key that you’ve used during the EMC PowerPath installation, you can retrieve it using the following command.
# powermt check_registration Key AAAA-BBBB-CCCC-DDDD-EEEE-FFFF Product: PowerPath Capabilities: All
5. Display EMC PowerPath Options
Displays the high level EMC SAN array options:
# powermt display options
6. Display PowerPath HBA Mode
This is similar to #1, but displays whether hba is enabled or not, as shown in the last column of the output.
# powermt display hba_mode Symmetrix logical device count=212 CLARiiON logical device count=0 Hitachi logical device count=0 Invista logical device count=0 HP xp logical device count=0 Ess logical device count=0 HP HSx logical device count=0 ============================================================================== ----- Host Bus Adapters --------- ------ I/O Paths ----- Stats ### HW Path Summary Total Dead Q-IOs Mode ============================================================================== 3 0/4/0/0/0/1 optimal 424 0 0 Enabled 5 0/5/0/0/0/1 optimal 424 0 0 Enabled
7. Display available I/O Paths
This displays all available path for your SAN device:
# powermt display paths
To display the path status for a specific storage device, use the display subcommand with the paths option and the dev= option:
# powermt display paths dev=device_name
8. Display Port Status
Displays the status of the individual ports on the HBA. i.e Whether the port is enabled or not.
# powermt displays port_mode
9. Display EMC PowerPath Version
Use the below command to identify the version number of EMC PowerPath software:
# powermt version
10. Check the I/O Paths
If we made changes to the HBA’s, or I/O paths, then run the powermt check, to take appropriate action. For example, if you manually removed an I/O path, check command will detect a dead path and remove it from the EMC path list.
# powermt check
11. Display Stats
To display the performance statistics for a specific storage device, use the display subcommand with the stats option and the dev= option:
# powermt display stats dev=device_name
12. Change State of the path
To set a specific storage device to a specific path state, use the set subcommand with the path_state option and the dev= option:
# powermt set path_state=state dev=device_name
Where state is the desired path state (e.g., active, standby, etc.)
13. Change load balance mode
To set a specific storage device to a specific load balance mode, use the set subcommand with the lb_mode option and the dev= option:
# powermt set lb_mode=mode dev=device_name
Where mode is the desired load balance mode (e.g., round_robin, weighted_path, etc.)
These are just a few examples of using the powermt command. There are many other options and subcommands available, which can be viewed by running the powermt command with the –help option.