A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. A plurality of access commands including a plurality of write commands are stored in a command queue, and the access commands are sorted into an execution order. A first write command is selected from the command queue based on the execution order, and a first part of the first write command is executed leaving a runt write command. The runt write command is executed between two of the sorted access commands so that the runt write command does not affect the execution order.

According to one embodiment, a magnetic disk device includes a power supply, a magnetic disk, a magnetic head, a communication unit that is communicable with a host computer and transmits a signal to the host computer at a first interval, a power supply monitor, a volatile memory that stores data related to read/write processing on the magnetic disk by the magnetic head, a non-volatile memory, and a controller that controls the communication unit to start processing of backing up the data stored in the volatile memory to the non-volatile memory and transmit the signal at a second interval longer than the first interval if power supplied from the power supply is detected to be disconnected based on monitoring of the power supply monitor.

According to one embodiment, a magnetic disk apparatus is provided with a magnetic disk, a buffer memory, and a control circuit. The magnetic disk has plural bands, each of which is a storage area in which data is written by the method of SMR. The control circuit receives a read request from outside. If the data requested to be read is first data of an update target stored in a first band among plural bands, the control circuit reads the first data from the first band, stores the first data in a buffer memory, and updates the first data in the buffer memory. Then, the control circuit transmits the first data in the buffer memory to the outside and writes the first data in the buffer memory to one of the plural bands.

A controller provides a plurality of first sections with numerical information on a first scale. The plurality of first sections are obtained by dividing a recording surface of a magnetic disk in units of first memory areas in each of which a first volume of data can be written by an SMR method. The first scale corresponds to a sequence of the first sections. The controller provides a plurality of second sections with numerical information on a second scale. The plurality of second sections are obtained by dividing the recording surface of the magnetic disk in units of second memory areas in each of which the first volume of data can be written by a CMR method. The second scale corresponds to a sequence of the second sections. The controller executes a plurality of commands in order based on a numerical information on the first scale or the second scale.

A disk device includes a magnetic disk, a magnetic head configured to read information from and write information to the magnetic disk, a housing having a mounting space in which the magnetic disk and the magnetic head are mounted, a substrate, and a sensor. The housing includes a wall and a hole extending therethrough to the mounting space. The substrate is attached to an outer side of the wall and sealing the hole. The sensor is mounted on the substrate.

Managing HDD performance at an IHS, including determining, for each write operation, a total number of revolutions of a disk of a HDD to complete the write operation and a number of revolutions of the disk of the HDD during the write operation that a write head of the HDD is off-track; calculating, for each write operation, a performance loss of the HDD; determining an average performance loss (APL) of the HDD over a first time period based on the performance loss of each write operation performed for the first time period; determining that the APL of the HDD over the first time period is greater than the threshold, and in response, performing a mitigation service at the IHS.

According to one embodiment, a magnetic disk device includes a first magnetic disk comprising a first recording surface accessed by using a first actuator system and second magnetic disk comprising a second recording surface accessed by using a second actuator system. The first recording surface includes a first area to which a logical address is mapped and a cache area. The second recording surface includes a second area to which a logical address is mapped and a cache area. When receiving first data whose final write destination is the first recording surface from a host, the controller writes the first data to a buffer memory. When the first event occurs, after the first data has been written to the buffer memory and before the first data has been written to the final write destination, the controller writes the first data in the buffer memory to the second area.

Techniques for managing a disk involve acquiring a message for an access operation for a disk, the message including a first status code at an operating system level for the access operation. The techniques further involve acquiring a second status code at a disk hardware level for the access operation if it is determined that the first status code indicates that the access operation fails. The techniques further involve determining, according to a handling policy corresponding to the second status code, whether the disk will be marked as faulty. The techniques further involve managing the disk based on a count of failed access operations for the disk if it is determined that the disk is not marked as faulty. Such techniques may quickly determine a specific reason for a failure of a disk access operation, making it possible to solve problems quickly, save time and improve the user experience.

A data storage device can have one or more rotating data media with data tracks that are radially disposed from a central spindle. The data tracks may be logically divided into multiple regions while a write strategy is generated with a region module to set a sequence of different regions for future data writes. Receipt of a data write request to the data storage media from a host can prompt the region module to classify the data write request as a sequential or random write in order to intelligently select a region to satisfy the data write request based on the write strategy to maximize data writing consistency for data associated with the data write request.

Storage can be allocated to workspaces in a ZFS-based environment. Workspaces can be associated with a workspace weightage. When a workspace is deployed on a client computing device, its workspace weightage can be used to determine an initial quota for a dataset to be created in a zpool for the workspace. The initial quota can be used to determine the size of the dataset. The workspace weightage may also be used to determine an expansion quota and a contraction quota that can be used to calculate the size of an expansion or contraction respectively. The use of workspace weightages and their associated quotas can ensure that the zpool is fairly shared by the various datasets that may be created therein for workspaces deployed on the client computing device.