Dynamic control of magnetic tape drive
AssigneeExabyte Corporation
InventorsMark R. Ayres, Alexander Stewart, Steven F. Hartung
Life of this patent
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Abstract
A magnetic tape drive dynamically adjusts a transport rate of tape (32) in accordance with a host data rate. The host data rate is assessed in relation to a data fill level of a buffer (116). A controller (130) of the drive compares the data fill level of the buffer with a buffer normalization value and generates an adjustment value for adjusting a signal indicative of the desired linear velocity of the tape. In one embodiment, the controller also dynamically changes the buffer normalization value to reflect e.g., historical performance of the host. In another embodiment the controller adjusts the transport rate when a head (100) is within a predetermined distance of a boundary point whereat the head must change tracks.
Claims71
A magnetic tape drive comprising:
- a transfer channel including a head which transduces data between the drive and a tape at a transfer channel data rate;
- a transport for providing relative motion between the head and the tape;
- a buffer for containing data transferred between the transfer channel and a host, the data transferred between the transfer channel and the host being one of data stored in the buffer from the host at a host data rate or data requested from the buffer by the host at the host data rate;
- a controller which dynamically adjusts the transfer channel data rate in accordance with the host data rate.
A magnetic tape drive comprising:
- a buffer which stores data, the data being one of data obtained from the host at a host data rate or data requested from the buffer by the host at the host data rate;
- a head which transduces data between the buffer and a tape;
- a transport for providing relative motion between the head and the tape at a transport rate;
- a controller which dynamically adjusts the transport rate in accordance with the host data rate.
A method of operating a magnetic tape drive, the method comprising:
- transferring data between a transfer channel and a head at a transfer channel data rate;
- providing relative motion between the head and the tape;
- transferring the data between the transfer channel and a buffer;
- transferring the data between the buffer and the host at a host data rate;
- and
- dynamically adjusting the transfer channel data rate in accordance with the host data rate.
A method of operating a magnetic tape drive, the method comprising:
- transferring data between a host and a buffer at a host data rate;
- providing relative motion between the head and the tape at a transport data rate;
- transducing the data between the buffer and the tape;
- dynamically adjusting the transport rate in accordance with the host data rate.
Dependencies are inferred from the claim text.