My Knowledgebase: Some Useful SAN Commands

On RedHat Linux servers with EMC SAN back-end storage

EMC uses PowerPath to manage multiple I/O paths, automatic load balancing, and path failover.

The following are list of PowerPath commands and their brief description

powermt Manage a PowerPath environment.

powercf Configure PowerPath devices (Solaris only).

emcpreg Manage PowerPath license registration.

emcpminor Check for free minor numbers.

emcpupgrade Convert PowerPath configuration files.

emcphostid Set or reset the host ID (HP-UX 11i v2.0 and higher and Linux only).

emcpadm List available PowerPath pseudo device names, list used PowerPath

pseudo device names, or rename PowerPath pseudo device.

We will be using powermt command most of the time and here are some details about the command.

powermt check

Check for, and optionally remove, dead paths.

Powermt check_registration

Check the state of the PowerPath license.

powermt display / (Previously powermt watch, now powermt watch is deprecated.)

Display the state of HBAs configured for PowerPath

powermt display options

Display options settings for storage system classes.

powermt display unmanaged

Display logical devices that have been excluded from PowerPath management

powermt load

Load a PowerPath configuration.

powermt manage (unmanage does the opposite)

Place a specified logical device, or specified storage system class, under PowerPath management

powermt version

Return the version of PowerPath that is installed on the host.

Powermt command Examples

Run powermt with no option/argument to get help

# powermt

Usage:

powermt check [force] [hba=|all] [dev=|all]

powermt check_registration

powermt config

powermt display nonvirtual {dev=|all}

[width=<#col>]

powermt display [ports] [dev=|all] [every=<#seconds>]

[width=<#col>]

powermt display latency [dev=|all] [every=<#seconds>]

[width=<#col>]

powermt display options

powermt display paths [every=<#seconds>] [width=<#col>]

powermt display unmanaged

powermt load [file=]

powermt manage {dev= | class=}

powermt release

powermt remove [force] hba=|all | dev=|all

powermt restore [hba=|all] [dev=|all]

powermt save [file=]

powermt set mode=active|standby [hba=|all] [dev=|all]

powermt set path_latency_monitor=on|off

powermt set path_latency_threshold=

powermt set periodic_autorestore=on|off

powermt set policy={ad|bf|co|lb|li|nr|re|rr|so} [dev=|all]

powermt set priority= [dev=|all]

powermt unmanage {dev= | class=}

powermt update lun_names

powermt version

Powermt display command

# powermt display

Symmetrix logical device count=15

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

==============================================================================

0 qla2xxx optimal 30 0 - 0 60

1 qla2xxx optimal 30 0 - 0 30

The above command shows there are two dual-port QLogic HBAs installed; the messaging server can see 15 logical devices

# powermt display

Symmetrix logical device count=5

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

==============================================================================

0 qla2xxx optimal 10 0 - 0 20

1 qla2xxx optimal 10 0 - 0 1065

The following command shows details about the 15 logical devices

# powermt display dev=all

Pseudo name=emcpowerc

Symmetrix ID=000190100725

Logical device ID=03D8

state=alive; policy=SymmOpt; priority=0; queued-IOs=0

Virtual Disk State

==============================================================================

---------------- Host --------------- - Stor - -- I/O Path - -- Stats ---

### HW Path I/O Paths Interf. Mode State Q-IOs Errors

==============================================================================

0 qla2xxx sdad FA 9cA active alive 0 2

1 qla2xxx sdat FA 8cA active alive 0 1

1 qla2xxx sdbj FA 9dA active alive 0 1

0 qla2xxx sdn FA 8dA active alive 0 2

Pseudo name=emcpowerb

Symmetrix ID=000190100725

Logical device ID=03D9

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

==============================================================================

0 qla2xxx sdae FA 9cA active alive 0 2

1 qla2xxx sdau FA 8cA active alive 0 1

1 qla2xxx sdbk FA 9dA active alive 0 1

0 qla2xxx sdo FA 8dA active alive 0 2

(Output truncated …)

The output from the above command shows that there are four paths to the virtual disks. For example the first virtual disk (emcpowerc) has the following paths:-

· Path from HBA 0 through storage interface FA 9CA

· Path from HBA 0 through storage interface FA 8DA

· Path from HBA 1 through storage interface FA 8CA

· Path from HBA 1 through storage interface FA 9DA

To display the above information for a specific device (E.g for partition1)

# powermt display dev=emcpowerk

Pseudo name=emcpowerk

Symmetrix ID=000190100725

Logical device ID=0B33

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

==============================================================================

1 qla2xxx sdal FA 8cA active alive 0 1

1 qla2xxx sdbb FA 9dA active alive 0 1

0 qla2xxx sdf FA 8dA active alive 0 2

0 qla2xxx sdv FA 9cA active alive 0 2

The following command shows the paths

# powermt display paths class=symm

Symm logical device count=15

==============================================================================

----- Host Bus Adapters --------- ------ Storage System ----- - I/O Paths -

### HW Path ID Interface Total Dead

==============================================================================

0 qla2xxx 000190100725 FA 9cA 15 0

0 qla2xxx 000190100725 FA 8dA 15 0

1 qla2xxx 000190100725 FA 8cA 15 0

1 qla2xxx 000190100725 FA 9dA 15 0

To Validate Installation / License

# powermt check_registration

Key

Product: PowerPath

Capabilities: All

For More Reading:

http://www.emc.com/microsites/clariion-support/ax100/pdf/300-002-310.pdf

On Solaris Servers:

On a Solaris server there is a command called luxadm that performs a variety of control and query tasks on SAN volumes, depending on the command-line arguments and options used.

The following command displays all attached devices:

vms03-som03{/}#luxadm probe

No Network Array enclosures found in /dev/es

Found Fibre Channel device(s):