Fast Recovery - for highly reliable 24 hour non-stop operation

Rebuild is a process that restores the contents of the failed disk from the remaining normal disks. If a hot spare disk (HS) is installed when a disk failure occurs, the rebuild process is performed from the hot spare and redundancy is restored.

Fast Recovery is a technology to shorten the rebuild time. No exclusive hot spare disk is available, but a reserved area for rebuild is prepared in each disk in the RAID group, as shown in the figure below.

Primary Storage System Failure

When a disk failure occurs, rebuild on reserved areas in multiple disks are performed simultaneously, unlike the traditional rebuild function where it is carried out disk by disk. This reduces the rebuild time for a 1TB disk to 90 minutes instead of 9 hours with traditional rebuild. RAID-6 is supported. Fast Recovery requires copy-back after a disk has been replaced.


  • Prevents interruptions to business operations due to server problems
  • Enables highly reliable 24 hour non-stop operation

Product Requirements

Supported StoragesAll-Flash ArraysETERNUS AF150 S3
ETERNUS AF250 S3/S2, AF250
ETERNUS AF650 S3/S2, AF650
Hybrid Storage SystemsETERNUS DX60 S5/S4/S3
ETERNUS DX100 S5/S4/S3, DX200 S5/S4/S3
ETERNUS DX500 S5/S4/S3, DX600 S5/S4/S3
ETERNUS DX8700 S3, DX8900 S4/S3

Further Information

Top of Page