This guide provides information about managing the supported storage subsystems attached to the server/cluster. The guide includes information about tiered storage, storage pools, system drives (SDs), using Hitachi Dynamic Provisioning (HDP) with the server, and other storage-related configuration and management features and functions.
- Child Topics
- Understanding tiered storage
- Storage management components
- Supported Hitachi storage systems
- Hitachi Dynamic Provisioning
You can use
Hitachi Dynamic Provisioning (HDP) software to improve your storage utilization. The HDP software uses storage-based virtualization layered on top of RAID technology (RAID on RAID) to enable virtual LUNs (dynamically provisioned volumes, DP-Vols) to draw space from multiple pool volumes. This aggregated space widens the storage bottleneck by distributing the I/O to more disks. The greater distribution insulates the server from the realities of the pool volumes (small capacities of individual disks).
- Configuration considerations when using
When your system must work with
HDP-based storage, there are things to remember that affect both the storage and the
NAS server. For detailed information on using
HDP with your particular storage, consult the
HDP software documentation.
When working with
HNAS systems, the
HDP software supports up to two levels of tiered storage (Tier 0 and Tier 1).
- Thin provisioning using the NAS server
HDP thin provisioning differs from thin provisioning achieved by the
- System drive groups and dynamic write balancing
- Expanding storage pools
- Configuring automatic file system expansion for an entire storage pool
Use this procedure to allow or prohibit automatic expansion of all file systems in the specified storage pool. This setting only affects auto-expansion; manual expansion of file systems in the storage pool is not affected by this setting.
- Renaming a storage pool
- Reducing the size of a storage pool
- Denying access to a storage pool
- Deleting a storage pool
A storage pool that does not contain file systems can be deleted at any time. If the storage pool contains file systems, you must unmount and then delete the file systems before you can delete the storage pool. After the pool has been deleted, its SDs become free and available for use by other storage pools.
- Using compression with flash module drives (FMDs)
Some storage contains flash module drives (FMDs) that transparently compress the data stored on them. Compression is a powerful way to reduce storage costs, but it does require extra care and monitoring by the administrator.
- Expanding file systems on flash storage
If an untiered span (or a single tier of a tiered span) has stripesets on two or more compressed HDP pools, the server cannot determine which stripeset, and, therefore, which HDP pool can most safely supply space for a filesystem-expansion.
- Detecting free space on flash storage
The server performs a regular scan for spans on compressed HDP pools which are in danger of failing because free physical space is very low.
- Using compression statistics
- Using UVM
- Taking over a UVM span
- Using multiple HDP pools
- Expanding a UVM-based filesystem
- Migrating data to a local cluster