Configuration guidelines for HNAS with HDP

Storage Subsystem Administration Guide for Hitachi NAS Platform

Version
14.8.x
Audience
anonymous
Part Number
MK-92HNAS012-29

Follow these configuration guidelines for best results.

On the storage:

  • Make every new HDP pool thinly provisioned.
  • Create enough DP-Vols to meet the expected size of the storage pool and to provide enough queue depth (minimum of four).
  • Limit each HDP pool to hosting only a single NAS server storage pool, particularly with low performing HDD’s; when using flash media using multiple spans per HDP pool is more acceptable. With the exception of tiered file systems, if you need fifty NAS server storage pools, create fifty HDP pools.
  • Do not share an HDP pool between two or more clusters, as disparate clusters are unaware of the other’s storage needs; additionally, troubleshooting performance concerns is exacerbated due to unknown workloads.
  • Do not share an HDP pool between an HNAS system and a foreign server, as disparate clusters are unaware of the other’s storage needs; additionally, troubleshooting performance concerns is exacerbated due to unknown workloads.

On the NAS server:

  • To avoid server timeouts when creating a new NAS server storage pool/span, wait for the HDP pool to finish formatting before creating the NAS server storage pool/span using NAS Manager or the span-create command.
    Note: If the HDP pool has finished formatting, but the NAS server does not detect the new DP-Vols, run the scsi-refresh CLI command so the NAS server will detect the new DP-Vols, , though this should not be necessary when HMO 7 is enabled on the target port host group.
  • For tiered file systems, you may either use two HDP pools when creating the NAS server storage pool that will host the tiered file systems or one can use a single HDP pool and pin DP Vols to the highest performing disks and use those as HNAS Tier 0.
  • Do not mix HDP DP-Vols and plain parity groups in a single NAS server storage pool/span. However, it is acceptable for some NAS server storage pools/spans to use HDP DP-Vols while other NAS server storage pools use parity groups.
  • For best performance, when creating a new NAS server storage pool based on HDP DP-Vols, specify all the DP-Vols in a single span-create command or NAS Manager equivalent. Do not create the storage pool on just a few of the DP-Vols and then make a series of small expansions.
  • Create as many file systems as needed and expand them as often as necessary (or allow them to auto-expand). For maximum flexibility and responsiveness, create small file systems and allow them to auto-expand as data is written to them.
    Note: The maximum size of a newly created file system on an HDP pool is 1 TiB, but file system expansions can increase the file system size to the maximum limit supported by your NAS server and underlying storage.