Read cache considerations

Server and Cluster Administration Guide for Hitachi NAS Platform

Version
15.1.x
Audience
anonymous
Part Number
MK-92HNAS010-35

The following recommendations are intended to take full advantage of read caching:

  • Because remote read caching requires CNS, you should review the cluster name space considerations.
  • In a cluster configuration, define one EVS per cluster node, and assign a read cache to each EVS.
  • Balance loads by moving file systems, instead of migrating EVS. If you migrate an EVS containing a read cache, the files in the read cache become invalidated and, assuming they are still cacheable, they would have to be cached again after the next read request.

    If an EVS containing a read cache is migrated to another cluster node that already has a read cache, the files in the migrated read cache are invalidated, and only the read cache that was not migrated will be used. If the EVS is migrated back to its original cluster node, the read cache will be used again, assuming another read cache has not been created on that cluster node in the interim.

  • Do not relocate read caches. If you relocate a read cache, the files in the read cache become invalidated and, assuming they are still cacheable, the previously cached files would have to be cached again after the next read request.