File system types

Storage Subsystem Administration Guide for Hitachi NAS Platform

Version
14.9.x
Audience
anonymous
Part Number
MK-92HNAS012-30

A file system typically consists of files and directories. Data about the files and directories (as well as many other attributes) is the metadata. The data within the file system (both user data and metadata) is stored in a storage pool.

Like storage pools, file system data (metadata and user data) may be stored in a single tier, or in multiple tiers.

  • When file system metadata and user data are stored on storage systems of a single storage tier, the file system is called an untiered file system. An untiered file system must be created in an untiered storage pool, it cannot be created in a tiered storage pool.

  • When file system metadata and user data are stored on storage systems of different storage tiers, the file system is called a tiered file system.

    In a tiered file system, metadata is stored on the highest performance tier of storage, and user data is stored on a lower-performance tier. Storing metadata on the higher-performance tier provides performance and cost benefits.

    A tiered file system must be created in a tiered storage pool; it cannot be created in an untiered storage pool.