Redundant Copy
Redundant Copy is a function that copies the data of a drive that shows a possible sign of failure to a hot spare.
When the Disk Patrol function determines that a drive requires preventative maintenance, the data of the maintenance target drive is recreated by the remaining drives and written to the hot spare. The Redundant Copy function enables data to be restored while maintaining data redundancy.
If a bad sector is detected when a drive is checked, an alternate track is automatically assigned. This drive is not recognized as having a sign of drive failure during this process. However, the drive will be disconnected by the Redundant Copy function if the spare sector is insufficient and the problem cannot be solved by assigning an alternate track.
Redundant Copy speed
The priority of the Redundant Copy with respect to host access can be specified. By increasing the Rebuild priority, the Redundant Copy operation is given a higher priority than the host access and the performance of the Redundant Copy operation is improved.
However, it should be noted that when the priority is high and a Redundant Copy operation is performed for a RAID group, the performance (throughput) of this RAID group may be reduced.
Refer to "Modify RAID Group Parameters" in "Web GUI User's Guide" for details.