摘要:
Embodiments of the present invention help to improve the capacity and the performance of a disk drive device. According to one embodiment, a data track pitch is set to each recording surface. The recording surfaces are divided into bands. A hard disk drive (HDD) sequentially moves a head to an adjacent data track in a band and performs a head switch at the band end in its data accessing. On a recording surface, the number of data tracks in each band is variable; and each band is constituted by different number of data tracks as necessary. The number of data tracks in each band is set so that the radial position of the band end comes close to the radial position of the corresponding band end on another recording surface. Accordingly, even if the recording surfaces have different variation rates of the data track pitch in the radial direction, increase in process time due to head switches can be suppressed.
摘要:
Embodiments of the present invention help to improve the capacity and the performance of a disk drive device. According to one embodiment, a data track pitch is set to each recording surface. The recording surfaces are divided into bands. A hard disk drive (HDD) sequentially moves a head to an adjacent data track in a band and performs a head switch at the band end in its data accessing. On a recording surface, the number of data tracks in each band is variable; and each band is constituted by different number of data tracks as necessary. The number of data tracks in each band is set so that the radial position of the band end comes close to the radial position of the corresponding band end on another recording surface. Accordingly, even if the recording surfaces have different variation rates of the data track pitch in the radial direction, increase in process time due to head switches can be suppressed.
摘要:
Embodiments of the invention improve the cache hit ratio of read data. A hard disk drive (HDD) according to an embodiment of the present invention determines whether the read buffer should be used in its entirety or the partial continuous space should be used to read read-data from the magnetic disk. When the HDD determines use of the partial continuous space, the HDD specifies the sub-buffer which is a continuous space wherein the leading-end position and the trailing-end position are coupled to each other, and executes data writing to the sub-buffer in parallel with data reading from the sub-buffer and transmission thereof to the host. The sub-buffer capacity coincides with the data length of the back data.
摘要:
Embodiments of the present invention provide a media drive capable of improving command processing performance by, when a plurality of commands is queued, shortening seek time and rotational latency, and also effectively making use of the shortened period of time. In one embodiment, a HDD includes a queue capable of storing a plurality of commands, and a queue manager for optimizing the execution order of the plurality of commands on the basis of whether or not the execution of each command requires access to a medium. The queue manager determines the execution order so that medium access processing of accessing a disk for execution, and data transfer processing of transferring data between the HDD and a host, are executed in parallel with each other. For example, read processing and transfer processing are executed in parallel with each other. The read processing is adaptive to read out a read command, data of which does not exist in the cache, from the disk into the cache. The transfer processing is adaptive to transfer a read command, data of which exists in the cache, to the host.
摘要:
Embodiments of the invention reduce the host's wait time by controlling buffer for a data storage device. In a hard disk drive (HDD) disclosed herein, after write data from a host is stored in a write buffer, the size of a continuous free space left forward from the end position of the stored write data is detected. If the size is smaller than a criterion size, that is, the size is not large enough to store the next command's write data, the write buffer is searched for a continuous free space not smaller than the criterion size. If a continuous free space not smaller than the criterion size is detected, the HDD sets a write pointer to the continuous free space. This makes it possible to receive the next write data from the host and therefore reduce the host's wait time.
摘要:
Embodiments of the invention raise the performance of a HDD by controlling the timing of notifying of command completion. In one embodiment, transmission of command completion notifications to a host is managed by a host interface manager. If two data write addresses respectively for two queued commands are adjacent or near to each other, that is, these addresses on the magnetic disk can be accessed without rotational latency, the host interface manager postpones the transmission of a command completion notification (X) concerning the first write command (X). Two command completion notifications (X) and (Y) are performed at a time after the write data (Y) for the next command is transmitted and its write to the medium is completed.
摘要:
A system and method are provided that reduce the amount of data held commonly in both high-ranking and low-ranking cache memories, thereby having each of those cache memories hold data more efficiently. More particularly, a computer system is provided with an HDC card 21 connected to an expansion bus 20 and an HDD unit 22 connected to the HDC card 21. The HDC card 21 is provided with a disk cache (high-ranking cache memory) and the HDD unit 22 is provided with a disk cache 54 (low-ranking cache memory). The HDC card 21 and the HDD unit 22 exchange select information for selecting a swap mode of each cache memory when the system is started up, thereby selecting different swap modes according to the exchanged select information respectively.
摘要:
Embodiments of the invention improve the cache hit ratio of read data. A hard disk drive (HDD) according to an embodiment of the present invention determines whether the read buffer should be used in its entirety or the partial continuous space should be used to read read-data from the magnetic disk. When the HDD determines use of the partial continuous space, the HDD specifies the sub-buffer which is a continuous space wherein the leading-end position and the trailing-end position are coupled to each other, and executes data writing to the sub-buffer in parallel with data reading from the sub-buffer and transmission thereof to the host. The sub-buffer capacity coincides with the data length of the back data.
摘要:
Embodiments of the present invention provide a media drive capable of improving command processing performance by, when a plurality of commands is queued, shortening seek time and rotational latency, and also effectively making use of the shortened period of time. In one embodiment, a HDD includes a queue capable of storing a plurality of commands, and a queue manager for optimizing the execution order of the plurality of commands on the basis of whether or not the execution of each command requires access to a medium. The queue manager determines the execution order so that medium access processing of accessing a disk for execution, and data transfer processing of transferring data between the HDD and a host, are executed in parallel with each other. For example, read processing and transfer processing are executed in parallel with each other. The read processing is adaptive to read out a read command, data of which does not exist in the cache, from the disk into the cache. The transfer processing is adaptive to transfer a read command, data of which exists in the cache, to the host.
摘要:
An external controller performs a thorough analysis and prediction on true requests from an application to issue a look-ahead request to an HDD or other auxiliary storage. An HDC card is connected to an HDD device which stores data and has a cache memory. The HDC card, which controls the HDD device, includes an access request tracer for tracing a true access request made by an application program executed by a host directly from the application program, a speculation request determination section for determining a speculation request to be expected later based on the traced true access request, and an HDC for issuing the determined speculation request to the HDD device.