Communication between cache and home

AFM uses the NFSv3 or NSD protocol for communication between clusters.

Communication for caching between clusters is performed by one or more nodes on the cache cluster designated as gateway nodes by using mmchnode. The target path on the home server must be NFS-exported on one or more nodes in the home cluster, or the home filesystem must be mounted on the cache cluster using the NSD protocol. Start of change For filesets in AFM RO mode, the target path at home NFS export can be Read-Only or Read-Write export. End of change The exported path or the home-mounted path of the home cluster is used in the cache cluster as the target when creating the cache fileset.

You can export paths with kerberos-enabled security levels from home to cache. At cache, configure kerberos clients at gateway nodes and run mmchconfig afmEnableNFSSec=yes -i. Gateway nodes can mount kerberos-enabled home exports with security levels like sys, krb5, krb5i, krb5p after afmEnableNFSSec is set to yes at cluster level.

AFM maintains a relationship between cache and home by monitoring home availability and reconnects accordingly.

Note: If a home fileset is removed or deleted, you must remove the export path first and re-start NFS at home.