摘要:
A disk drive is disclosed comprising a disk, a head, and a ramp located near an outer periphery of the disk. The disk drive further comprises control circuitry operable to load the head off the ramp over the disk, receive an unload command to perform an unload operation, evaluate a number of unloads relative to an unload limit that varies over time, and when the number of unloads exceeds the unload limit, delay the unload operation.
摘要:
A hybrid drive is disclosed comprising a head actuated over a disk, and a non-volatile semiconductor memory (NVSM). When a write command is received from a host that is mapped to the NVSM, the write command is serviced by writing data to the NVSM, and when a life remaining of the NVSM falls below a threshold, by also writing a copy of the data to the disk.
摘要:
Systems and methods for writing a sequence of data to a disk drive using sorted data zones are provided. In one embodiment, a multi-head disk drive comprises a plurality of disk surfaces, wherein each disk surface comprises a plurality of data zones, each data zone having a data transfer rate different from the other zones of the respective disk surface. The multi-head disk drive also comprises a head assembly comprising a plurality of heads, wherein each head is configured to write data to a respective one of the disk surfaces, and a controller configured to operate the plurality of heads to sequentially write a sequence of data blocks to the plurality of disk surfaces in accordance with a list of head-zone combinations ordered from highest data rate to lowest data rate, each head-zone combination corresponding to one of the heads and a data zone of the respective disk surface.
摘要:
A data storage device is disclosed comprising a non-volatile memory and control circuitry operable to evaluate a physical feature of the data storage device, wherein the physical feature is physically alterable by a user. When the physical feature is in a first state, host access to first secure data stored in the non-volatile memory is enabled, and when the physical feature is in a second state, the host access to the first secure data is disabled and host access to second data stored in the non-volatile memory is enabled.
摘要:
A disk drive is disclosed which receives a plurality of access commands from a host, where each access command identifies a target track. The access commands are stored in a command queue, and for each command in the command queue, a seek length is computed corresponding to a number of tracks between a current track the head is over and the target track of the access command. A seek time is computed in response to the seek length using a seek profile comprising a first plurality of seek length segments and a variance group comprising a second plurality of seek length segments. Each seek length segment corresponds to a range of seek lengths, and the first plurality of seek length segments is different than the second plurality of seek length segments.
摘要:
A hybrid drive is disclosed comprising a head actuated over a disk, and a non-volatile semiconductor memory (NVSM). Access commands are received from a host including disk read commands. When a high workload of disk access commands is detected, data of at least one disk read command is migrated to the NVSM.
摘要:
A data storage device is disclosed comprising a non-volatile memory and control circuitry operable to evaluate a physical feature of the data storage device, wherein the physical feature is physically alterable by a user. When the physical feature is in a first state, host access to first secure data stored in the non-volatile memory is enabled, and when the physical feature is in a second state, the host access to the first secure data is disabled and host access to second data stored in the non-volatile memory is enabled.
摘要:
A host activity measure indicative of a frequency of disk access commands received by a disk drive is determined, and then compared against a host activity threshold. A subsystem activity measure indicative of an activity level of a disk drive subsystem is also determined, and then compared against a subsystem activity threshold. Based at least in part on a determination that 1) the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and 2) the subsystem activity measure is indicative of less activity than the subsystem activity threshold, an operating frequency of a disk drive processor is increased.
摘要:
A disk drive is disclosed comprising a non-volatile write cache and a head actuated over a disk. A plurality of write commands are received from a host, wherein each write command comprises write data. A workload for a non-cache area of the disk is determined, and when the workload for the non-cache area of the disk is less than a threshold independent of a workload for the write cache, substantially all of the write data is stored in the non-cache area of the disk. When the workload for the non-cache area of the disk is greater than the threshold independent of the workload for the write cache, a first percentage of the write data is stored in the non-volatile write cache and a second percentage of the write data is stored in the non-cache area of the disk, wherein the first percentage is proportional to the workload for the non-cache area of the disk.
摘要:
A hybrid drive is disclosed comprising a head actuated over a disk, and a non-volatile semiconductor memory (NVSM). A first execution time needed to execute commands in a NVSM command queue is estimated, and a second execution time needed to execute commands in a disk command queue is estimated. An access command is inserted into a selected one of the NVSM command queue and the disk command queue in response to the first and second execution times, and one of the first and second execution times is updated in response to an estimated execution time of the access command.