Topic
2 replies Latest Post - ‏2013-10-04T12:15:21Z by davislh
davislh
davislh
2 Posts
ACCEPTED ANSWER

Pinned topic GPFS 3.4 over EMC Powerpath

‏2013-09-04T16:04:03Z |

I am about to build a SLES Linux GPFS Server, having multiple paths to the EMC VMAX.

The GPFS Clients will also have multiple paths to the EMC VMAX..

All of the machines (Server and Clients) will see the Same LUNS which will be used for the GPFS filesystem.

I want to use Powerpath 5.5 SP1on all the machines.

Has anyone setup GPFS (3.4) where powerpath presented the LUNs (emcpowerX#) and GPFS used those Powerpath

presented LUNs, willing to share the experience?

 

 

  • HajoEhlers
    HajoEhlers
    251 Posts
    ACCEPTED ANSWER

    Re: GPFS 3.4 over EMC Powerpath

    ‏2013-09-26T16:33:23Z  in response to davislh

    We use powerpath on AIX and we have no problems.

    Note:

    • We use /var/mmfs/etc/nsddevices to select only powerpath devices.
    • For the harddisk devices ( hdiskX )  we set the reserve_policy to no_reserve ( Must be translated to linux ) .

    hth

    Hajo

     

  • davislh
    davislh
    2 Posts
    ACCEPTED ANSWER

    Re: GPFS 3.4 over EMC Powerpath

    ‏2013-10-04T12:15:21Z  in response to davislh

    I will update my post to provide details for my  and your future reference.

    Setting up GPFS to use Powerpath disk is as simple as using the powerpath names vs the MPIO or native disk names, ie hdiskX.

    Powerpath names on AIX: hdiskpowerX

    Powerpath names on Linux: emcpowerX

    Pseudo name=emcpowera
    Symmetrix ID=000192600471
    Logical device ID=0A9B
    state=alive; policy=SymmOpt; queued-IOs=0
    ==============================================================================
    --------------- Host ---------------          - Stor -       -- I/O Path --        -- Stats ---
    ###  HW Path               I/O Paths      Interf.       Mode     State     Q-IOs Errors
    ==============================================================================
       2    lpfc                          sdau             FA 10fA     active   alive         0         0
       2    lpfc                          sdah             FA  8fA      active   alive          0         0
       1    lpfc                          sdu               FA  9fA       active   alive         0         0
       1    lpfc                          sdh               FA  7fA       active   alive         0         0

    Next is a small clip(copy) of the contents of a file I created (nsddesc.txt) that is fed to the mmcrnsd command (mmcrnsd -F nsddesc.txt):
    (Make sure you make a COPY your input file BEFORE running mmcrnsd )

    # Note: my setup below was for just one GPFS Server.. If you have multiple GPFS Servers, either make sure the emcpowerX devices
    represent the SAME set of LUNs, otherwise you have some modifications to make either BEFORE creating the NSDs or after.. (see mmchnsd)

    Note: the first field: emcpowerX  are powerpath disk names.

    # cat nsddesc.txt

           emcpowera:cgogq01hdqwl::metadataOnly:1:cgonsd01:
           emcpowerb:cgogq01hdqwl::metadataOnly:1:cgonsd02:
           emcpowerc:cgogq01hdqwl::metadataOnly:1:cgonsd03:
           emcpowerd:cgogq01hdqwl::dataOnly:1:cgonsd04:
           emcpowere:cgogq01hdqwl::dataOnly:1:cgonsd05:
           emcpowerf:cgogq01hdqwl::dataOnly:1:cgonsd06:
           emcpowerg:cgogq01hdqwl::dataOnly:1:cgonsd07:
           emcpowerh:cgogq01hdqwl::dataOnly:1:cgonsd08:
     

    The modified verion of the nsddesc.txt file AFTER running mmcrnsd:

    # cat nsddesc.txt

          # emcpowera:cgogq01hdqwl::metadataOnly:1:cgonsd01:
          cgonsd01:::metadataOnly:1::system
          # emcpowerb:cgogq01hdqwl::metadataOnly:1:cgonsd02:
          cgonsd02:::metadataOnly:1::system
          # emcpowerc:cgogq01hdqwl::metadataOnly:1:cgonsd03:
          cgonsd03:::metadataOnly:1::system
          # emcpowerd:cgogq01hdqwl::dataOnly:1:cgonsd04:
          cgonsd04:::dataOnly:1::system
           # emcpowere:cgogq01hdqwl::dataOnly:1:cgonsd05:
           cgonsd05:::dataOnly:1::system
           # emcpowerf:cgogq01hdqwl::dataOnly:1:cgonsd06:
           cgonsd06:::dataOnly:1::system
           # emcpowerg:cgogq01hdqwl::dataOnly:1:cgonsd07:
           cgonsd07:::dataOnly:1::system
           # emcpowerh:cgogq01hdqwl::dataOnly:1:cgonsd08:
           cgonsd08:::dataOnly:1::system
     

    Just continue with the rest of your setup, ie. mmcrfs DEVICE -F nsddesc.txt -A yes -B ....