Assign Global Hot Spare

Overview

This function registers a drive as a Global Hot Spare.

A Global Hot Spare is a spare drive (hot spare) that is registered in the RAID group instead of the failed drive when a drive failure occurs. A Global Hot Spare, unlike a Dedicated Hot Spare, can be used by all of the RAID groups.

If a drive fails, data copy (rebuild) to a Global Hot Spare starts automatically.

If the Copybackless function is disabled and the failed drive is replaced with a normal drive, the data is copied back to the replacement drive. The Global Hot Spare that is used instead of the failed drive then returns as a spare drive.

If the Copybackless function is enabled, the Hot Spare is registered in the RAID group after rebuilding and is used as a data drive. The failed drive in the RAID group is changed to a Global Hot Spare after the rebuilding is complete. If the failed drive is replaced with a normal drive, the replacement drive can be used as a Global Hot Spare.

Requirements for Hot Spares

  • Drives that are currently used cannot be registered as a hot spare.

    • The drive status is "Present"

    • The drives are not registered in RAID groups, TPPs, FTRPs, REC Disk Buffers, or Extreme Cache Pools

  • Make sure to register a hot spare with the same or a larger capacity than the data drives. If the hot spare capacity is smaller than the data drive, the drive does not work as the hot spare.

  • When a mix of Online disks, Nearline disks, SSDs, Online SEDs, Nearline SEDs, and SSD SEDs is installed together in the storage system, a hot spare of each type is required. Register the Dedicated Hot Spare with the same capacity as the maximum capacity drive for each type.

  • When multiple types of SSDs (SSD-H/SSD-M/SSD-L/SSD-H SED/SSD-M SED/SSD-L SED) are installed together in the storage system, a hot spare for each type is required. Register the hot spare with the same capacity as the maximum capacity SSD for each type.

  • Hot spares can be registered in any slots of the CEs and the DEs.

Caution

  • To use hot spares on a priority basis, make sure to register the Dedicated Hot Spare for a RAID group that contains important data using the [Assign Dedicated Hot Spare] function.

  • The hot spare with the same type with a failed drive may not be used since the installed position (*1) of the hot spare is given higher priority than the drive type of the hot spare, and Online disks and Nearline disks can be substituted.

    If different types of drives are mixed, the recommended action is to install a hot spare for each different drive type on each installed position (*1).

    *1  :  For details about the installed position, refer to "Hot Spares" in "Design Guide".

    The installed positions are given priority when hot spares are selected for the ETERNUS DX500 S5/DX600 S5/DX900 S5 and the ETERNUS DX8900 S4.
Note

  • If the Dedicated Hot Spare is registered for a RAID group to which a failed drive belongs, the Dedicated Hot Spare is used before the Global Hot Spare. If there is no unused Dedicated Hot Spare and the drive fails, the Global Hot Spare is used.

  • Depending on the hot spare usage status, a hot spare with a different capacity and type from the failed drive may be used.

  • To use the Copybackless function, the rebuild destination Hot Spare must satisfy some conditions. Refer to the [Setup Subsystem Parameters] function for details.

User Privileges

Availability of Executions in the Default Role

Default role Availability of executions
Monitor  
Admin
StorageAdmin
AccountAdmin  
SecurityAdmin  
Maintainer

Refer to "User Roles and Policies" for details on the policies and roles.

Operating Procedures

  1. Select the drive (multiple selections can be made) that is to be used as a Global Hot Spare and click [Assign Global HS] in [Action].

    → A confirmation screen appears.

  2. Click the [OK] button.

    → Registration of the Global Hot Spare starts.

  3. Click the [Done] button to return to the [Drives] screen.