Disk lubricant management in data storage device
View Patent ↗It is determined whether one or more heads of a data storage device (DSD) have been within a radial position of one or more disks of the DSD for more than a threshold period of time. When it is determined that the one or more heads have been within a radial position of the one or more disks for more than the threshold period of time, the one or more heads are radially moved by more than a predetermined distance to reduce a development of variations in a distribution of lubricant on a first surface of the one or more disks.
1. A data storage device (DSD) comprising:
one or more disks including a first surface for storing data, the first surface having a lubricant distributed thereon;
one or more heads for writing data on the one or more disks and for reading data from the one or more disks;
a voice coil motor (VCM) for radially moving the one or more heads in relation to the one or more disks; and
a controller configured to:
determine whether the one or more heads have been within a radial position of the one or more disks for more than a threshold period of time; and
when it is determined that the one or more heads have been within the radial position of the one or more disks for more than the threshold period of time, control the VCM to radially move the one or more heads by more than a predetermined distance to reduce a development of variations in the distribution of the lubricant on the first surface.
2. The DSD of claim 1 , further comprising one or more sliders with each of the one or more heads located on a respective slider, and wherein the predetermined distance is based on a size of the one or more sliders.
3. The DSD of claim 2 , wherein each of the one or more heads is located on a trailing pad of a respective slider, and wherein the predetermined distance is based on a size of the trailing pad.
4. The DSD of claim 3 , wherein the predetermined distance is equal to a length or a width of the trailing pad.
5. The DSD of claim 1 , wherein the threshold period of time is based on a time for variations in the distribution of the lubricant to develop on the first surface while the one or more heads are within a radial position in relation to the first surface.
6. The DSD of claim 1 , wherein the controller is further configured to:
cause a head of the one or more heads to write data on the first surface in at least one zone of tracks during a write operation; and
control the VCM to radially move the head outside of the at least one zone by at least the predetermined distance in response to a completion of the write operation in the at least one zone to reduce the development of variations in the distribution of the lubricant on the first surface.
7. The DSD of claim 1 , wherein the one or more disks include a second surface for storing data with the second surface in alignment with and parallel to the first surface,
wherein the first surface includes a first reserved zone of tracks for storing frequently accessed data and the second surface includes a second reserved zone of tracks for storing frequently accessed data, and
wherein the first reserved zone is radially positioned away from the second reserved zone by at least the predetermined distance.
8. The DSD of claim 1 , wherein the controller is further configured to redistribute lubricant on the first surface by controlling the VCM to radially move a head of the one or more heads across a previously written portion of the first surface multiple times in succession in response to a completion of a write operation in the previously written portion of the first surface.
9. The DSD of claim 1 , wherein the first surface includes a first reserved zone of tracks for storing frequently accessed data, and wherein the controller is further configured to:
determine whether a head of the one or more heads is within the predetermined distance from the first reserved zone; and
when it is determined that the head is within the predetermined distance from the first reserved zone, control the VCM to radially move the head away from the first reserved zone by at least the predetermined distance.
10. The DSD of claim 1 , wherein the controller is further configured to:
perform a write operation by causing a head of the one or more heads to write data in a zone of tracks on the first surface; and
in response to finishing the writing of data in the zone of tracks during the write operation, redistribute the lubricant in the finished zone of tracks by controlling the VCM to radially move the head across the finished zone of tracks before continuing the write operation in a different zone of tracks.
11. The DSD of claim 10 , wherein the controller is further configured to control the VCM to radially move the head across the finished zone of tracks multiple times in succession before continuing the write operation in the different zone of tracks.
12. The DSD of claim 10 , wherein the controller is further configured to log a redistribution of lubricant for the finished zone of tracks.
13. A method for operating a data storage device (DSD), the method comprising:
determining whether one or more heads of the DSD have been within a radial position of one or more disks of the DSD for more than a threshold period of time; and
when it is determined that the one or more heads have been within a radial position of the one or more disks for more than the threshold period of time, radially moving the one or more heads by more than a predetermined distance to reduce a development of variations in a distribution of lubricant on a first surface of the one or more disks.
14. The method of claim 13 , wherein each of the one or more heads is located on a respective slider of one or more sliders, and wherein the predetermined distance is based on a size of the one or more sliders.
15. The method of claim 14 , wherein each of the one or more heads is located on a trailing pad of the respective slider, and wherein the predetermined distance is based on a size of the trailing pad.
16. The method of claim 15 , wherein the predetermined distance is equal to a length or a width of the trailing pad.
17. The method of claim 13 , wherein the threshold period of time is based on a time for variations to develop in the distribution of the lubricant on the first surface while a head of the one or more heads is within a radial position in relation to the first surface.
18. The method of claim 13 , further comprising:
writing data on the first surface in at least one zone of tracks using a head of the one or more heads during a write operation; and
radially moving the head outside of the at least one zone by at least the predetermined distance in response to a completion of the write operation in the at least one zone to reduce the development of variations in the distribution of the lubricant on the first surface.
19. The method of claim 13 , wherein the first surface includes a first reserved zone of tracks for storing frequently accessed data, and wherein the method further comprises:
determining whether a head of the one or more heads is within the predetermined distance from the first reserved zone; and
when it is determined that the head is within the predetermined distance from the first reserved zone, radially moving the head away from the first reserved zone by at least the predetermined distance.
20. The method of claim 13 , further comprising:
performing a write operation using a head of the one or more heads to write data on a portion of the first surface; and
in response to the completion of the write operation, redistributing the lubricant in the portion of the first surface by radially moving the head across the portion of the first surface multiple times in succession.
21. The method of claim 13 , further comprising:
performing a write operation using a head of the one or more heads to write data in a zone of tracks on the first surface; and
in response to finishing the writing of data in the zone of tracks during the write operation, redistributing the lubricant in the finished zone of tracks by radially moving the head across the finished zone of tracks before continuing the write operation in a different zone of tracks.
22. The method of claim 21 , further comprising radially moving the head across the finished zone of tracks multiple times in succession before continuing the write operation in the different zone of tracks.
23. The method of claim 21 , further comprising logging a redistribution of lubricant for the finished zone of tracks.