PowerPath command examples

The EMC powermt utility helps you manage I/O paths from the server to the EMC storage device. In this post we discuss how to use powermt command with practical examples.

1. powermt display — Display High Level HBA I/O Paths powermt display command (without any arguments), displays the available HBAs and their current status. The following examples, shows that there are 2 HBAs connected to the server, both the HBAs are in active condition with 32 I/O path's each.

# powermt display
VNX logical device count=8==============================================================================
----- Host Bus Adapters ---------  ------ I/O Paths -----  ------ Stats ------
###  HW Path                       Summary   Total   Dead  IO/Sec Q-IOs Errors
==============================================================================
3072 pci@9,600000/SUNW,qlc@1/fp@0,0  optimal      32      0       -     1      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0  optimal      32      0       -     2      0

2. powermt display dev=all — Display All Attached LUNsThis is the most frequently used powermt command, which will display all the attached logical devices to the server.

# powermt display dev=all
Pseudo name=emcpower37a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601600BE02A00046526A7567FE211 [GOLF05-nlcd04_apps]
state=alive; policy=CLAROpt; queued-IOs=0
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d0s0 SP B7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d0s0 SP A7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d0s0 SP B6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d0s0 SP A6    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d0s0 SP B5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d0s0 SP A5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d0s0 SP B4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d0s0 SP A4    active   alive      0      0


Pseudo name=emcpower38a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601600BE02A008E15833B5D7FE211 [GOLF05-chr]
state=alive; policy=CLAROpt; queued-IOs=11
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d1s0 SP B5    active   alive      2      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d1s0 SP B4    active   alive      2      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d1s0 SP A4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d1s0 SP A5    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d1s0 SP B6    active   alive      4      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d1s0 SP B7    active   alive      3      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d1s0 SP A6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d1s0 SP A7    active   alive      0      0


Pseudo name=emcpower39a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601600BE02A002296F5E1ED7FE211 [GOLF05-golf05_tmp]
state=alive; policy=CLAROpt; queued-IOs=0
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d2s0 SP B4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d2s0 SP B5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d2s0 SP A5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d2s0 SP A4    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d2s0 SP B6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d2s0 SP B7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d2s0 SP A6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d2s0 SP A7    active   alive      0      0


Pseudo name=emcpower40a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601600BE02A00A2CB1D92FB7FE211 [GOLF05-land_certs]
state=alive; policy=CLAROpt; queued-IOs=0
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d3s0 SP B5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d3s0 SP B4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d3s0 SP A5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d3s0 SP A4    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d3s0 SP B6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d3s0 SP B7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d3s0 SP A6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d3s0 SP A7    active   alive      0      0


Pseudo name=emcpower41a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601600BE02A002ADA286CFD7FE211 [GOLF05-nlcd05_apps]
state=alive; policy=CLAROpt; queued-IOs=5
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d4s0 SP B4    active   alive      2      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d4s0 SP B5    active   alive      1      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d4s0 SP A4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d4s0 SP A5    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d4s0 SP B6    active   alive      1      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d4s0 SP B7    active   alive      1      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d4s0 SP A6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d4s0 SP A7    active   alive      0      0


Pseudo name=emcpower42a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601600BE02A00980F3056FE80E211 [GOLF05-chr2]
state=alive; policy=CLAROpt; queued-IOs=0
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d5s0 SP A5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d5s0 SP A4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d5s0 SP B5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d5s0 SP B4    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d5s0 SP A6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d5s0 SP B6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d5s0 SP B7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d5s0 SP A7    active   alive      0      0


Pseudo name=emcpower43a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601603B402C00C0EB0F369D9BE211 [GOLF05-golf05_tmp-02]
state=alive; policy=CLAROpt; queued-IOs=0
Owner: default=SP A, current=SP A       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d6s0 SP A4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d6s0 SP A5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d6s0 SP B5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d6s0 SP B4    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d6s0 SP B6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d6s0 SP B7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d6s0 SP A6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d6s0 SP A7    active   alive      0      0


Pseudo name=emcpower44a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601603B402C001A28D6E3F758E311 [GOLF05-nlcd04_apps1]
state=alive; policy=CLAROpt; queued-IOs=0
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d7s0 SP A4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d7s0 SP A5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d7s0 SP B5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d7s0 SP B4    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d7s0 SP B7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d7s0 SP B6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d7s0 SP A7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d7s0 SP A6    active   alive      0      0

The above command output indicates the following:

  • Pseudo name=emcpower37a — The device name that can be used by the server. For example, /dev/emcpower37a.
  • CLARiiON ID=AAA00000000000 [dev-server] - EMC CLARiiON CX3 serial number and the server name.
  • Logical device ID=11111111 [LUN 1] — LUN number. For example, LUN 1.
  • state=alive; policy=CLAROpt; — This displays that this particular LUN is valid and using the CLAROpt policy.
  • Owner: default=SP B, current=SP B — This indicates that the default (and current) owner for this LUN is storage processor SP B.

3. powermt display dev=emcpowera — Display specific LUN

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.

# powermt display dev=emcpower37a
Pseudo name=emcpower37a
VNX ID=CKM00114901418 [Golf05]
Logical device ID=600601600BE02A00046526A7567FE211 [GOLF05-nlcd04_apps]
state=alive; policy=CLAROpt; queued-IOs=0
Owner: default=SP B, current=SP B       Array failover mode: 4
==============================================================================
--------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
==============================================================================
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016F3EA044D4d0s0 SP B7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601673EA044D4d0s0 SP A7    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t5006016E3EA044D4d0s0 SP B6    active   alive      0      0
3072 pci@9,600000/SUNW,qlc@1/fp@0,0 c2t500601663EA044D4d0s0 SP A6    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016D3EA044D4d0s0 SP B5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601653EA044D4d0s0 SP A5    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t5006016C3EA044D4d0s0 SP B4    active   alive      0      0
3074 pci@9,600000/SUNW,qlc@2/fp@0,0 c4t500601643EA044D4d0s0 SP A4    active   alive      0      0

If the device is not available, you'll get a “Bad dev value” as shown below.

# powermt display dev=emcpowerc

Bad dev value emcpowerc, or not under Powerpath control.

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. powermt display options — Display EMC PowerPath Options Displays the high level EMC SAN array options as shown below.

# powermt display options
 Default storage system class: all
 Show CLARiiON LUN names: true
 Path Latency Monitor: Off
 Path Latency Threshold: 0 Sec.
 Storage
 System Class Attributes
 ------------ ----------
 Symmetrix periodic autorestore = on
 status = managed
 CLARiiON periodic autorestore = on
 status = managed
 Hitachi periodic autorestore = on
 status = managed
 Invista periodic autorestore = on
 status = managed
 HP xp periodic autorestore = on
 status = managed
 Ess periodic autorestore = on
 status = managed
 HP HSx periodic autorestore = on
 status = managed

6. powermt display hba_mode — 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=0
CLARiiON logical device count=1
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
==============================================================================
 1 qla2xxx optimal 2 0 0 Enabled
 2 qla2xxx optimal 2 0 0 Enabled

7. powermt display path — Display available I/O Paths. This displays all available path for your SAN device.

# powermt display paths
Symmetrix logical device count=0
==============================================================================
----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -
### HW Path ID Interface Total Dead
==============================================================================
CLARiiON logical device count=1
==============================================================================
----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -
### HW Path ID Interface Total Dead
==============================================================================
 1 qla2xxx AAA00000000000 SP A4 1 0
 1 qla2xxx AAA00000000000 SP B4 1 0
 2 qla2xxx AAA00000000000 SP A5 1 0
 2 qla2xxx AAA00000000000 SP B5 1 0
Hitachi logical device count=0
==============================================================================
----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -
### HW Path ID Interface Total Dead
==============================================================================
Invista logical device count=0
==============================================================================
----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -
### HW Path ID Interface Total Dead
==============================================================================
HP xp logical device count=0
==============================================================================
----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -
### HW Path ID Interface Total Dead
==============================================================================
Ess logical device count=0
==============================================================================
----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -
### HW Path ID Interface Total Dead
==============================================================================
HP HSx logical device count=0
==============================================================================
----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -
### HW Path ID Interface Total Dead
==============================================================================

8. powermt displays port_mode — Display Port Status Displays the status of the individual ports on the HBA. i.e Whether the port is enabled or not.

# powermt display port_mode
Storage class = Symmetrix
==============================================================================
----------- Storage System --------------- -- I/O Paths -- --- Stats ---
 ID Interface Wt_Q Total Dead Q-IOs Mode
==============================================================================
Storage class = CLARiiON
==============================================================================
----------- Storage System --------------- -- I/O Paths -- --- Stats ---
 ID Interface Wt_Q Total Dead Q-IOs Mode
==============================================================================
 AAA00000000000 SP A4 256 1 0 0 Enabled
 AAA00000000000 SP B4 256 1 0 0 Enabled
 AAA00000000000 SP A5 256 1 0 0 Enabled
 AAA00000000000 SP B5 256 1 0 0 Enabled

9. powermt version — Display EMC PowerPath Version How to identify the version number of EMC PowerPath software?

# powermt version
EMC powermt for PowerPath (c) Version 5.3 (build 185)

10. powermt check — Check the I/O Paths If you have made changes to the HBA's, or I/O paths, just execute powermt check, to take appropriate action. For example, if you have manually removed an I/O path, check command will detect a dead path and remove it from the EMC path list.

# powermt check
 Warning: storage_system I/O path path_name is dead.
 Do you want to remove it (y/n/a/q)?

Note: If you want powermt to automatically remove all dead paths, without any confirmation, execute “powermt check force”.

11. powermt set mode hba — Forcefully set the mode for a specific HBA You can change the mode of a specific HBA to either standby or active using this command. Following example, changes HBA #1’s mode from active to standby.

# powermt set mode=standby hba=1

After the above command, you can see the mode for HBA#1 changed to standby, as shown below.

# powermt display dev=all
Pseudo name=emcpowera
CLARiiON ID=AAA00000000000 [dev-server]
Logical device ID=1111111111111111111 [LUN 1]
state=alive; policy=CLAROpt; priority=0; queued-IOs=0
Owner: default=SP B, current=SP B Array failover mode: 1
==============================================================================
---------------- Host --------------- - Stor - -- I/O Path - -- Stats ---
### HW Path I/O Paths Interf. Mode State Q-IOs Errors
==============================================================================
 1 qla2xxx sdd SP A4 standby alive 0 0
 1 qla2xxx sde SP B4 standby alive 0 0
 2 qla2xxx sdf SP A5 active alive 0 0
 2 qla2xxx sdg SP B5 active alive 0 0

Note: Path mode can also be “unlic” indicating that you've not registered the PowerPath with proper License key.

Note: Some powermt commands (for example, powermt set port_disable), is restricted to certain platform and storage type — On AIX and Solaris, only Fibre channel is supported. On HP-UX, only iSCSI and Fibre are supported. On Linux, Only iSCSI (HBAs) and Fibre are supported.

12. powermt remove — Delete an I/O Path Use this command to remove any specific I/O path (or) a whole device.

The following example has 4 I/O Paths.

# powermt display dev=all
==============================================================================
---------------- Host --------------- - Stor - -- I/O Path - -- Stats ---
### HW Path I/O Paths Interf. Mode State Q-IOs Errors
==============================================================================
 1 qla2xxx sdd SP A4 standby alive 0 0
 1 qla2xxx sde SP B4 standby alive 0 0
 2 qla2xxx sdf SP A5 active alive 0 0
 2 qla2xxx sdg SP B5 active alive 0 0

To remove I/O Path sdd, execute the following powermt remove command.

# powermt remove dev=sdd
# powermt display dev=all
==============================================================================
---------------- Host --------------- - Stor - -- I/O Path - -- Stats ---
### HW Path I/O Paths Interf. Mode State Q-IOs Errors
==============================================================================
 1 qla2xxx sde SP B4 standby alive 0 0
 2 qla2xxx sdf SP A5 active alive 0 0
 2 qla2xxx sdg SP B5 active alive 0 0

Following will remove all I/O Path for a particular device. i.e To remove /dev/emcpowera, do the following. If the /dev/emcpowera is mounted and used by some program, following command will not work.

# powermt remove dev=emcpowera

13. powermt config — Configure PowerPath This command checks for available EMC SAN logical devices and add those to PowerPath configuration list. Powermt config command, sets some of the options to it's default values. For example, write throttling = off, HBA mode = active, CLARiiON policy = CLAROpt, etc.

Possible EMC SAN LUN policy values are: Adaptive, BasicFailover, CLAROpt, LeastBlocks, LeastIos, NoRedirect, Request, RoundRobin, StreamIO, or SymmOpt.

After you execute the powermt config, if you don't like any of the default values, you should change it accordingly.

# powermt config

14. powermt restore — Make Dead I/O Path Alive If you have dead I/O paths, and if you've done something to fix the issue, you can request PowerPath to re-check the paths and mark it as active using powermt restore command.

When you execute powermt restore, it does an I/O path check. If a previously dead path is alive, it will be marked as alive, and if a previously alive path is dead, it will be marked as dead.

For some reason, if you see the default owner and the current owner of a particular LUN is not the same storage processor, then execute the following command, which will make the current owner of the LUN same as the default owner.

# powermt restore dev=all

Instead of dev, you can also specify class in the powermt restore command. Class can be one of the following depending on your system.

symm — Symmetrix
clariion - CLARiiON
invista — Invista
ess — IBM ESS
hitachi — Hitachi Lightning TagmaStore
hpxp - HP StorageWorks XP, or EVA series
hphsx — HP StorageWorks EMA, or MA
all — All systems
15. Powermt Save and Load — Save and Restore PowerPath Configurations
powermt save — Save the current Powerpath Configuration
If you are changing the PowerPath configurations for testing purpose, you can save the current configuration using powermt save command.

Use this method to backup the current PowerPath Configurations.

# powermt save

This will save the current powermt configuration to /etc/powermt.custom file. Following is the partial content of this file.

#cat /etc/powermt.custom
global:version:5.3.0.0.0:4.1.0
path_c:sdd:sdd:qla2xxx:0x111
path_c:sde:sde:qla2xxx:0x111
adapter: 1: 1:qla2xxx:0x111:1:0:111:0:11:0
adapter: 2: 2:qla2xxx:0x111:1:0:111:0:111:0
arrPort_c:04000000:04000000:111:111
mpext_cfg:unused:Mp:0:symm:0:0
...
...

If you want to store the current PowePath configuration to a different file, do the following.

# powermt save file=/etc/powermt.21-Aug-2010

powermt load — Load a previously saved EMC PowerPath Configuration When you are testing EMC PowerPath configuration, if you are not satisfied with the new configuration, you can go back to the previous configuration.

For example, to restore the configuration to a specific file that you created in the above powermt save example, do the following.

# powermt load file=/etc/powermt.21-Aug-2010