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4 replies Latest Post - ‏2012-10-23T09:11:31Z by HajoEhlers
SystemAdmin
SystemAdmin
2092 Posts
ACCEPTED ANSWER

Pinned topic Rename nsd name with sequence

‏2012-10-18T09:42:09Z |
Hi,

i removed some nsd disks and recreated to change the pool name.
below is the nsd details

Disk details before recreation

File system Disk name NSD servers

seismic gpfs1nsd (directly attached)
seismic gpfs2nsd (directly attached)
seismic gpfs3nsd (directly attached)
(free disk) gpfs4nsd (directly attached)
(free disk) gpfs5nsd (directly attached)
(free disk) gpfs6nsd (directly attached)
(free disk) gpfs7nsd (directly attached)
(free disk) gpfs8nsd (directly attached)
(free disk) gpfs9nsd (directly attached)

Disk details after recreation of nsd

File system Disk name NSD servers

seismic gpfs1nsd (directly attached)
seismic gpfs2nsd (directly attached)
seismic gpfs3nsd (directly attached)
(free disk) gpfs11nsd (directly attached)
(free disk) gpfs12nsd (directly attached)
(free disk) gpfs13nsd (directly attached)
(free disk) gpfs14nsd (directly attached)
(free disk) gpfs15nsd (directly attached)
(free disk) gpfs16nsd (directly attached)

Here Disk Name sequence was changed after regeneration of nsd disk. How to get the previous sequence ie from gpfs1nsd to gpfs9nsd. Whats is the impact if i continue with new sequence of names. This s a three node GPFS cluster environment.

Thanks in advance.
Peter
Updated on 2012-10-23T09:11:31Z at 2012-10-23T09:11:31Z by HajoEhlers
  • ezhong
    ezhong
    32 Posts
    ACCEPTED ANSWER

    Re: Rename nsd name with sequence

    ‏2012-10-18T14:39:13Z  in response to SystemAdmin
    Hi Peter,

    What you observed is the correct behavior of mmcrnsd. As mentioned in the man page of mmcrnsd, If a desired name is not specified, a NSD name not used in any prior NSD will be generated by GPFS code. You can use the new NSD names the same way as you used the previous NSD names.

    If you specify your desired NSD names (not starting with "gpfs") as input to the mmcrnsd command, then those names can be reused for NSD recreation.
  • sdenham
    sdenham
    70 Posts
    ACCEPTED ANSWER

    Re: Rename nsd name with sequence

    ‏2012-10-18T14:48:28Z  in response to SystemAdmin
    "Whats is the impact if i continue with new sequence of names."

    There's no special meaning to the names. If you keep the new GPFS-generated names, everything will still work fine, there will just be a gap in the names.
  • SystemAdmin
    SystemAdmin
    2092 Posts
    ACCEPTED ANSWER

    Re: Rename nsd name with sequence

    ‏2012-10-21T06:55:16Z  in response to SystemAdmin
    Thanks ezhong & sdenham for your prompt response,

    Although the names doesn’t affect any behavior of regular system activity, it looks odd for documentation or listing the disks and hard to figureout between NSD names and device names.

    Since these systems are in the implantation and testing phase, I am trying to get the proper disk sequence through some workarounds.

    Thanks again…
    Peter Regin B
    • HajoEhlers
      HajoEhlers
      251 Posts
      ACCEPTED ANSWER

      Re: Rename nsd name with sequence

      ‏2012-10-23T09:11:31Z  in response to SystemAdmin
      > I am trying to get the proper disk sequence through some workarounds.
      I never saw a benefit of given certain numbers to disks ( Ok , i am using AIX ) and it made even live harder to do so.

      So my question: What the hell is the benefit of having disks in a certain "order" ?
      IMHO on the long run any "fixed" relationship between a GPFS disk descriptor and its final "usage" will cause more problems then it will solve.

      cheers
      Hajo

      A simple script gives me on AIX all required information based on lspv,powermt , mmlsnsd & mmlsdisk.
      ( We are using EMC )
      
      /cluster/sbin/getsancfg Filesystem      hdisk   pvid    vg      EMCResourceGroup        lun_name lun gpfs11 hdiskpower0     00589a3d30cc428d        gpfs1089nsd     node1_sg        T0_LUN126 0x.... gpfs11 hdiskpower1     00589a3d30c85c7f        gpfs1102nsd     node1_sg        T1_LUN6  0x.... gpfs2 hdiskpower2     00589a3d30cba623        gpfs1123nsd     group1_sg        T0_LUN19 0x....