Important information about remote access

There is some additional information about this topic that you should take into consideration.

When working with GPFS™ file systems accessed by nodes that belong to other GPFS clusters, consider the following points:
  1. A file system is administered only by the cluster where the file system was created. Other clusters may be allowed to mount the file system, but their administrators cannot add or delete disks, change characteristics of the file system, enable or disable quotas, run the mmfsck command, and so forth. The only commands that other clusters can issue are list type commands, such as: mmlsfs, mmlsdisk, mmlsmount, and mmdf.
  2. Since each cluster is managed independently, there is no automatic coordination and propagation of changes between clusters, like there is between the nodes within a cluster.

    This means that if the administrator of cluster1 (the owner of file system gpfs1) decides to delete it or rename it, the information for gpfs1 in cluster2 becomes obsolete, and an attempt to mount gpfs1 from cluster2 will fail. It is assumed that when such changes take place, the two administrators will inform each other. The administrator of cluster2 can then use the update or delete options of the mmremotefs command to make the appropriate changes.

  3. If the names of the contact nodes change, the name of the cluster changes, or the public key file changes, use the update option of the mmremotecluster command to reflect the changes.
  4. Use the show option of the mmremotecluster and mmremotefs commands to display the current information about remote clusters and file systems.
  5. If the cluster that owns a file system has a maxblocksize configuration parameter that is different from the maxblocksize configuration parameter of the cluster that desires to mount a file system, a mismatch may occur and file system mount requests may fail with messages to this effect. Check your maxblocksize configuration parameters on both clusters using the mmlsconfig command. Correct any discrepancies with the mmchconfig command.
Parent topic: Accessing a remote GPFS file system