Topics: EMC, SAN, Storage, System Admin

Recovering from dead EMC paths

If you run:

# powermt display dev=all
And you notice that there are "dead" paths, then these are the commands to run in order to set these paths back to "alive" again, of course, AFTER ensuring that any SAN related issues are resolved.

To have PowerPath scan all devices and mark any dead devices as alive, if it finds that a device is in fact capable of doing I/O commands, run:
# powermt restore
To delete any dead paths, and to reconfigure them again:
# powermt reset
# powermt config
Or you could run:
# powermt check

Topics: EMC, Installation, ODM, SAN, Storage

How to cleanup AIX EMC ODM definitions

From powerlink.emc.com:

  1. Before making any changes, collect host logs to document the current configuration. At a minimum, save the following: inq, lsdev -Cc disk, lsdev -Cc adapter, lspv, and lsvg
  2. Shutdown the application(s), unmount the file system(s), and varyoff all volume groups except for rootvg. Do not export the volume groups.
    # varyoffvg <vg_name>
    Check with lsvg -o (confirm that only rootvg is varied on)
    If no PowerPath, skip all steps with power names.
  3. For CLARiiON configuration, if Navisphere Agent is running, stop it:
    # /etc/rc.agent stop
  4. Remove paths from Powerpath configuration:
    # powermt remove hba=all
  5. Delete all hdiskpower devices:
    # lsdev -Cc disk -Fname | grep power | xargs -n1 rmdev -dl
  6. Remove the PowerPath driver instance:
    # rmdev -dl powerpath0
  7. Delete all hdisk devices:
    For Symmetrix devices, use this command:
    # lsdev -CtSYMM* -Fname | xargs -n1 rmdev -dl
    For CLARiiON devices, use this command:
    # lsdev -CtCLAR* -Fname | xargs -n1 rmdev -dl
  8. Confirm with lsdev -Cc disk that there are no EMC hdisks or hdiskpowers.
  9. Remove all Fiber driver instances:
    # rmdev -Rdl fscsiX
    (X being driver instance number, i.e. 0,1,2, etc.)
  10. Verify through lsdev -Cc driver that there are no more fiber driver instances (fscsi).
  11. Change the adapter instances in Defined state
    # rmdev -l fcsX
    (X being adapter instance number, i.e. 0,1,2, etc.)
  12. Create the hdisk entries for all EMC devices:
    # emc_cfgmgr
    or
    # cfgmgr -vl fcsx
    (x being each adapter instance which was rebuilt). Skip this part if no PowerPath.
  13. Configure all EMC devices into PowerPath:
    # powermt config
  14. Check the system to see if it now displays correctly:
    # powermt display
    # powermt display dev=all
    # lsdev -Cc disk
    # /etc/rc.agent start

Topics: EMC, SAN, Storage

Display the status of EMC SAN devices

An easy way to see the status of your SAN devices is by using the following command:

# powermt display
Symmetrix logical device count=6
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 fscsi0             optimal     6    0       -     0      0
  1 fscsi1             optimal     6    0       -     0      0
To get more information on the disks, use:
# powermt display dev=all

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