Storage device with I/O counter for partial data reallocation

A storage device comprising:

• a first plurality of physical disks corresponding to a logical disk, wherein the logical disk is partitioned into a plurality of groups, each group comprising at least one segment on at least one of the first plurality of physical disks;
• at least a second physical disk corresponding to the logical disk;
• a processor, coupled with the first plurality of physical disks and with the at least a second physical disk, the processor configured to:
• partition one group of the plurality of groups into a plurality of sub-groups;
• and
• for each sub-group of the plurality of sub-groups but one, copy the sub-group to at least one segment on the at least a second physical disk;
• and
• a disk controller, coupled with a first memory, with the first plurality of physical disks and with the at least a second physical disk, and coupled to receive I/O requests for the logical disk from at least one host computer, the disk controller configured to:
• determine one or more of the physical disks of the first plurality of physical disks and the at least a second physical disk to which an I/O request corresponds;
• and
• perform the requested I/O to the determined one or more of the physical disks.

A method of reallocating data among physical disks corresponding to a logical disk, the method comprising:

• partitioning a logical disk into a plurality of groups, wherein each group comprises a plurality of segments on at least one of a first plurality of physical disks corresponding to the logical disk;
• determining a most frequently accessed group of the plurality of groups;
• partitioning the most frequently accessed group into a plurality of sub-groups, including partitioning each segment of the plurality of segments comprising the most frequently accessed group into a plurality of sub-segments, wherein each sub-group comprises at least one sub-segment;
• for each sub-group of the plurality of sub-groups but one, allocating at least one segment on at least one of a second plurality of physical disks corresponding to the logical disk, each segment on the second plurality of disks corresponding to the at least one sub-segment comprising the sub-group;
• and
• for each sub-group of the plurality of sub-groups but the one, copying the corresponding at least one sub-segment to the corresponding at least one segment on the at least one of the second plurality of physical disks.

A storage device comprising:

• a first plurality of physical disks corresponding to a logical disk, wherein the logical disk is partitioned into a plurality of groups, each group comprising at least one segment on at least one of the first plurality of physical disks;
• at least a second physical disk corresponding to the logical disk;
• a processor, coupled with the first plurality of physical disks and with the at least a second physical disk, the processor configured to:
• partition one group of the plurality of groups into a plurality of sub-groups;
• and
• for each sub-group of the plurality of sub-groups but one, copy the sub-group to at least one segment on the at least a second physical disk.