2 replies Latest Post - ‏2014-05-16T17:37:22Z by renarg
103 Posts

Pinned topic GPFS4.1 CCR Functionality

‏2014-05-16T07:47:47Z |

Hallo GPFS-Team,

first i know we had only the base-package of Version 4.1, hopefully the first fixpak comming soon.

Now i tested to create a new 4 node Cluster an see some problems with the ccr-function.

The steps are:

mmcrluster -N NodeA:quorum -r .. -R .. --ccr-enable

This works fine.

Then we want to add the next node with

mmaddnode -N NodeB:quorum  and after that we see a error:

mmaddnode -N NodeB:quorum
Fri May 16 09:04:04 CEST 2014: mmaddnode: Processing node
No GPFS quorum in new node set (1 of 2 nodes are joined; 2 are required):
  joined (ip)
  up (ip)
mmaddnode: Unexpected error from /usr/lpp/mmfs/bin/mmccr.  Return code: 149
mmaddnode: Unable to change the CCR quorum node configuration.
mmaddnode: Removing GPFS cluster files from the nodes in the cluster . . .
mmaddnode: Command failed. Examine previous error messages to determine cause.

Are there any restrictions on that steps to do first create a Cluster with only one node and then add the next ones?

Thanks Renar


  • gcorneau
    145 Posts

    Re: GPFS4.1 CCR Functionality

    ‏2014-05-16T17:16:17Z  in response to renarg

    It's not a GPFS restriction, per se, but a law of numbers:

    You need a majority of quorum nodes available to maintain CCR quorum.

    When you go from 1 to 2 quorum nodes, you drop below 51% (simple majority), until that new quorum node is up and running.

    A simple solution is to create the cluster with the majority of quorum nodes during the mmcrcluster command.  At that point, adding additional nodes shouldn't interfere with CCR quorum.

    I can't speak to any patches that may change this behavior, I've no idea.

    • renarg
      103 Posts

      Re: GPFS4.1 CCR Functionality

      ‏2014-05-16T17:37:22Z  in response to gcorneau

      Hallo Glen,

      thanks for that info. That what I thought.

      Regards Renar