Data management for a data storage device using a last resort zone

Information

  • Patent Grant
  • 9263088
  • Patent Number
    9,263,088
  • Date Filed
    Wednesday, June 4, 2014
    10 years ago
  • Date Issued
    Tuesday, February 16, 2016
    8 years ago
Abstract
A data storage device (DSD) includes a non-volatile memory (NVM) media for storing data. A last resort zone of the NVM media is associated with a higher risk of data loss or data corruption than other portions of the NVM media and is reserved as unavailable for storing data. It is determined whether a current data storage capacity and/or an environmental condition for the NVM media has reached a threshold. The last resort zone is set as available for storing data if it is determined that the threshold has been reached and data is written in the last resort zone.
Description
BACKGROUND

Data Storage Devices (DSDs) are often used to record data onto or to reproduce data from a storage media. One type of storage media includes a rotating magnetic disk where a magnetic head of the DSD can read and write data in tracks on a surface of the disk.


Data stored on the disk may become susceptible to corruption or data loss due to a variety of conditions. For example, data stored on a particular area of the disk surface may become unreadable if the DSD is dropped and components of the DSD contact the disk surface. In another example, contaminants or surface defects may also cause loss or corruption of data written on the disk.





BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the embodiments of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the disclosure and not to limit the scope of what is claimed.



FIG. 1 is a block diagram depicting a Data Storage Device (DSD) according to an embodiment.



FIG. 2A is an example of a translation table with a last resort zone that has been reserved as unavailable for storing data according to an embodiment.



FIG. 2B depicts the translation table of FIG. 2B after the last resort zone has been set as available for storing data according to an embodiment.



FIG. 3 is a flowchart for a data management process according to an embodiment.



FIG. 4 is a flowchart for a data management process according to another embodiment.





DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth to provide a full understanding of the present disclosure. It will be apparent, however, to one of ordinary skill in the art that the various embodiments disclosed may be practiced without some of these specific details. In other instances, well-known structures and techniques have not been shown in detail to avoid unnecessarily obscuring the various embodiments.



FIG. 1 shows computer system 100 according to an embodiment which includes host 101 and Data Storage Device (DSD) 106. Computer system 100 can be, for example, a computer system (e.g., server, desktop, mobile/laptop, tablet, smartphone, etc.) or other electronic device such as a digital video recorder (DVR). In this regard, computer system 100 may be a stand-alone system or part of a network. Those of ordinary skill in the art will appreciate that system 100 and DSD 106 can include more or less than those elements shown in FIG. 1 and that the disclosed processes can be implemented in other environments.


In the example embodiment of FIG. 1, DSD 106 includes both solid state memory 128 and disk 150 for storing data. In this regard, DSD 106 can be considered a Solid State Hybrid Drive (SSHD) in that it includes both solid state Non-Volatile Memory (NVM) media and disk NVM media. In other embodiments, each of disk 150 or solid state memory 128 may be replaced by multiple Hard Disk Drives (HDDs) or multiple Solid State Drives (SSDs), respectively, so that DSD 106 includes pools of HDDs or SSDs. In yet other embodiments, the NVM media of DSD 106 may only include disk 150 or solid state memory 128.


DSD 106 includes controller 120 which includes circuitry such as one or more processors for executing instructions and can include a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), hard-wired logic, analog circuitry and/or a combination thereof. In one implementation, controller 120 can include a System on a Chip (SoC).


Host interface 126 is configured to interface DSD 106 with host 101 and may interface according to a standard such as, for example, PCI express (PCIe), Serial Advanced Technology Attachment (SATA), or Serial Attached SCSI (SAS). As will be appreciated by those of ordinary skill in the art, host interface 126 can be included as part of controller 120.


Sensor 142 detects an environmental condition of DSD 106, such as a temperature, acceleration, or vibration of DSD 106, and provides an input to controller 120 based on the detected condition. In some embodiments, controller 120 may modify operation of DSD 106 based on the input received from sensor 142. As discussed in more detail below, controller 120 may also set a last resort zone of NVM media as available for storing data if it is determined that an environmental condition has reached a threshold.


In the example of FIG. 1, disk 150 is rotated by a spindle motor (not shown). DSD 106 also includes head 136 connected to the distal end of actuator 130 which is rotated by Voice Coil Motor (VCM) 132 to position head 136 in relation to disk 150. Controller 120 can control the position of head 136 and the rotation of disk 150 using VCM control signal 30 and SM control signal 34, respectively.


As appreciated by those of ordinary skill in the art, disk 150 may form part of a disk pack with additional disks radially aligned below disk 150. In addition, head 136 may form part of a head stack assembly including additional heads with each head arranged to read data from and write data to a corresponding surface of a disk in a disk pack.


Disk 150 includes a number of radial spaced, concentric tracks (not shown) for storing data on a surface of disk 150. The tracks on disk 150 are grouped together into zones of tracks (e.g., zones 152 and last resort zone 154) with each track divided into a number of sectors that are spaced circumferentially along the tracks.


In some implementations, the tracks on disk 150 are written by a write element of head 136 using Shingled Magnetic Recording (SMR) so as to overlap adjacent tracks. SMR provides a way of increasing the amount of data that can be stored in a given area on disk 150 by overlapping tracks like roof shingles. The non-overlapping portion then serves as a narrow track that can be read by a read element of head 136.


Although a higher number of tracks per inch is ordinarily possible with SMR, the overlap in tracks can generally prevent new writes to a previously overlapped track since such new writes would affect data written in the overlapping track. For this reason, tracks are usually sequentially written in SMR implementations to avoid affecting previously written data.


In the embodiment of FIG. 1, last resort zone 154 is associated with a higher risk of data loss than other portions of the NVM media of DSD 106. For example, last resort zone 154 can include an area of disk 150 that may often become damaged as a result of mechanical shock to DSD 106. Such mechanical shock may occur when DSD 106 is dropped during operation or when DSD 106 is initially tested by a manufacturer.


In FIG. 1, last resort zone 154 is located in an Outer Diameter (OD) portion of disk 150. The OD portion of disk 150 may become damaged when DSD 106 is dropped during operation as DSD 106 takes precautionary measures to move head 136 away from disk 150 to reduce the likelihood of damage to disk 150 upon impact. In addition, the OD portion of disk 150 may become damaged during a manufacturer's mechanical shock testing of DSD 106 if disk 150 is addressed beginning at the OD portion of disk 150.


In other embodiments, last resort zone 154 can be located in different portions of disk 150 or in a portion of solid state memory 128. In one embodiment, last resort zone 154 is located in an Inside Diameter (ID) portion of disk 150. The ID portion of disk 150 may be associated with a higher risk of data loss due to an increased amount of contaminants near the ID portion or from other disk surface irregularities caused by clamping disk 150 to a spindle (not shown). In other embodiments, last resort zone 154 can be assigned during operation or factory testing as a zone with more than a predetermined number of defects or errors.


In addition to disk 150, the NVM media of DSD 106 also includes solid state memory 128 for storing data. While the description herein refers to solid state memory generally, it is understood that solid state memory may comprise one or more of various types of memory devices such as flash integrated circuits, Chalcogenide RAM (C-RAM), Phase Change Memory (PC-RAM or PRAM), Programmable Metallization Cell RAM (PMC-RAM or PMCm), Ovonic Unified Memory (OUM), Resistance RAM (RRAM), NAND memory (e.g., Single-Level Cell (SLC) memory, Multi-Level Cell (MLC) memory, or any combination thereof), NOR memory, EEPROM, Ferroelectric Memory (FeRAM), Magnetoresistive RAM (MRAM), other discrete NVM chips, or any combination thereof. Where DSD 106 stores data in solid state memory 128, last resort zone 154 could be a location such as a page, block, die, etc. in solid state memory 128 that may have certain detected or known weaknesses/conditions similar to those described above, and the embodiments described herein can equally apply to such cases as well.


Volatile memory 140 can include, for example, a Dynamic Random Access Memory (DRAM) which can be used by DSD 106 to temporarily store data. Data stored in volatile memory 140 can include data read from NVM media (e.g., disk 150 or solid state memory 128), data to be written to NVM media, instructions loaded from firmware of DSD 106 for execution by controller 120, or data used in executing firmware of DSD 106.


As shown in the embodiment of FIG. 1, volatile memory 140 stores translation table 22, which provides a mapping between Logical Block Addresses (LBAs) used by host 101 to address data and physical locations (e.g., Physical Block Addresses (PBAs)) indicating physical locations on disk 150 or in solid state memory 128. In one implementation, a back-up copy of a translation table is stored on disk 150 which is updated to account for changes to translation table 22 stored in volatile memory 140. In other embodiments, translation table 22 may be stored in a different location such as in solid state memory 128. Translation table 22 is described in more detail below with reference to FIGS. 2A and 2B.


In operation, host interface 126 receives read and write commands from host 101 via host interface 126 for reading data from and writing data to the NVM media of DSD 106. In response to a write command from host 101, controller 120 may buffer the data to be written for the write command in volatile memory 140.


For data to be written to disk 150, controller 120 can encode the buffered data into write signal 32 which is provided to head 136 for magnetically writing data to the surface of disk 150.


In response to a read command for data stored on disk 150, controller 120 positions head 136 via VCM control signal 30 to magnetically read the data stored on the surface of disk 150. Head 136 sends the read data as read signal 32 to controller 120 for decoding, and the data is buffered in volatile memory 140 for transferring to host 101.


For data to be stored in solid state memory 128, controller 120 receives data from host interface 126 and may buffer the data in volatile memory 140. In one implementation, the data is then encoded into charge values for charging cells (not shown) of solid state memory 128 to store the data.


In response to a read command for data stored in solid state memory 128, controller 120 in one implementation reads current values for cells in solid state memory 128 and decodes the current values into data that can be transferred to host 101. Such data may be buffered by controller 120 before transferring the data to host 101 via host interface 126.



FIG. 2A provides an example of translation table 22 with last resort zone 154 reserved as unavailable for storing data according to an embodiment. In the embodiment of FIGS. 2A and 2B, controller 120 manages access to NVM media using translation table 22. In this regard, translation table 22 is used to map LBAs for associated data to PBAs corresponding to physical locations where the associated data is stored in the NVM media. Controller 120 maintains translation table 22 in volatile memory 140 to keep track of the changes made to the data stored in the NVM media of DSD 106. As noted above, translation table 22 may also be stored, or alternatively stored, in solid state memory 128 or disk 150.


In some implementations, translation table 22 is used as part of an indirection process for SMR zones on disk 150. When data is updated for a particular LBA, the update is often written in a different location on disk 150 than where the data for the LBA was previously written to avoid having to rewrite an entire SMR zone of overlapping tracks. A translation table, such as translation table 22, can be used to keep track of where the current versions of the data are stored for a particular LBA.


As shown in FIG. 2A, each entry (i.e., row) of translation table 22 includes an LBA and a PBA which is mapped to the LBA for the entry. In other embodiments, translation table 22 can include LBA ranges mapped to PBA ranges which can be represented with a starting address and an extent length.


The PBAs in translation table 22 indicate locations in the NVM media of DSD 106 such as locations on disk 150 or in solid state memory 128. Entries 24 of translation table 22 include PBAs for last resort zone 154 and entries 26 of translation table 22 include PBAs for portions of the NVM media that are outside of last resort zone 154. In the example of FIG. 2A, the PBAs for last resort zone 154 begin at PBA 0 and continue to PBA n. The PBAs for the portions of NVM media outside of last resort zone 154 begin at PBA n+1 and continue to PBA n+m.


As noted above, the physical location of last resort zone 154 is not limited to an OD portion of disk 150 in other embodiments. Similarly, the range of PBAs identifying last resort zone 154 is not limited to a particular range of PBAs. For example, the range of PBAs for last resort zone 154 in other embodiments may occur at the end of a total PBA range for the NVM media or between the end and beginning of the total PBA range for the NVM media.


In the example of FIG. 2A, last resort zone 154 has been reserved by having no LBAs allocated to entries 24 and with LBAs having been allocated to locations outside of last resort zone 154. This is shown by the LBAs allocated for entries 26 but not for entries 24. When performing read and write commands for host 101, DSD 106 will access the portions of the NVM media corresponding to entries 26 without accessing last resort zone 154. Since last resort zone 154 is not allocated LBAs, it is not yet visible or available to host 101.


Although entries 26 have been allocated LBAs 0 to m, the LBAs for entries 26 do not need to be sequentially ordered with respect to their respective PBAs. Moreover, the use of LBA indirection for disk 150 or solid state memory 128 can result in a non-sequential ordering of LBAs with respect to the corresponding PBAs.


Once a storage capacity associated with entries 26 has reached a threshold, controller 120 can set last resort zone 154 as available for storing data by allocating LBAs to entries 24 for last resort zone 154. This can ordinarily allow for DSD 106 to reduce the likelihood of data loss or corruption by waiting until all or most of the NVM media outside of last resort zone 154 has been used before storing data in the more vulnerable last resort zone 154.


In other embodiments, controller 120 can set last resort zone 154 as available for storing data based on whether an environmental condition for the NVM media has reached a threshold. For example, sensor 142 may detect a high operating temperature for solid state memory 128 or disk 150 that may make it more likely to encounter an error in storing or retrieving data from the NVM media. Sensor 142 can provide an input to controller 120 indicating a high temperature condition, and controller 120 may then set last resort zone 154 as available for storing data by allocating LBAs to entries 24 for last resort zone 154. This can ordinarily allow for DSD 106 to save less vulnerable portions of the NVM media for storing data when there is less likely to be an error due to the environmental condition. Controller 120 may also follow particular write settings to safeguard against data loss when storing data in last resort zone 154 or may store a duplicate copy of the data to protect against data loss or corruption due to the environmental condition.


In another example, sensor 142 may detect an environmental condition of a high vibration condition that may make it more likely to encounter an error in storing or retrieving data from the NVM media. Sensor 142 can provide an input to controller 120 indicating the high vibration condition, and controller 120 may then set last resort zone 154 as available for storing data by allocating LBAs to entries 24 for last resort zone 154. Different write settings can then be used when writing data in last resort zone 154 to reduce the likelihood of an error during the environmental condition.


In yet other embodiments, controller 120 can set last resort zone 154 as available for storing data when both a current data storage capacity and an environmental condition have reached a threshold. In other words, controller 120 may only set last resort zone 154 as available after a certain amount of data has been stored outside of last resort zone 154 and sensor 142 detects a particular environmental condition.


As noted above, DSD 106 may also change the way in which it writes data in last resort zone 154 when compared to areas outside of last resort zone 154. For example, controller 120 may perform a write verification process (e.g., a conditioned write verify process) for data written in last resort zone 154 where data is read after it has been written to verify the written data.


In another example, controller 120 may reduce the number of write retries when attempting to write data in a sector of last resort zone 154. In more detail, controller 120 may control head 136 to attempt to write data in a particular sector for a predetermined number of write retries before relocating the data to a different sector such as a spare sector. Controller 120 may reduce the number of write retries such as from ten write retries to only three when writing data in last resort zone 154. This can be done to improve the time for completing write commands in last resort zone 154 since it may be more likely that additional write retries will be unsuccessful if last resort zone 154 has been identified as having a large amount of defects.


In addition, controller 120 may adjust write settings for writing data in last resort zone 154 by changing a track density for writing data in last resort zone 154. In one example, the track density or a number of Tracks Per Inch (TPI) can be decreased so as to reduce the chances of encountering errors when reading or writing data in last resort zone 154. Since more errors can be expected when tracks are in closer proximity to each other, lowering the track density for last resort zone 154 can generally lessen the likelihood of errors in last resort zone 154, which is already more susceptible to errors.


Controller 120 may also limit the types of data written in last resort zone 154. In this regard, the data written in last resort zone 154 may be required to have a duplicate copy stored outside of last resort zone 154 to prevent loss of the data. In one example, last resort zone 154 may be used as a scratch area for performing garbage collection of zones 152 so that a copy of data stored in a particular zone 152 is stored in last resort zone 154 while the zone 152 is garbage collected.


Less stringent write settings may be used based on whether there is a duplicate copy of the data stored outside of last resort zone 154. For example, as long as a copy of the data exists elsewhere in the NVM media, controller 120 may relax the write settings for writing the data in last resort zone 154 by, for example, not performing a write verification of the copy stored in last resort zone 154.


In another implementation, the data written in last resort zone 154 may be data that is accessed with a reading frequency and/or a writing frequency outside of a threshold frequency or data with a lower priority, since this data may be at a higher risk of loss or corruption by being stored in last resort zone 154. In one such example, controller 120 may store cold data in last resort zone 154 that is not frequently accessed for reading or writing.



FIG. 2B depicts translation table 22 after last resort zone 154 has been set as available for storing data according to an embodiment. As shown in FIG. 2B, LBAs have been allocated to entries 24 for last resort zone 154. The allocated LBAs begin with m+1 and continue to m+n. As discussed in more detail below with reference to FIG. 3, the allocation of LBAs to last resort zone 154 occurs after controller 120 determines that a current data storage capacity for the NVM media has reached a threshold. After allocating the LBAs to last resort zone 154, DSD 106 can perform read and write commands in last resort zone 154 and last resort zone 154 becomes visible or available to host 101.



FIG. 3 is a flowchart for a data management process that can be performed by controller 120 according to an embodiment. The process of FIG. 3 begins in block 304 with controller 120 reserving last resort zone 154 as unavailable for storing data. This can be accomplished as noted above with FIG. 2A by allocating LBAs to portions of the NVM media outside of last resort zone 154 without allocating LBAs to last resort zone 154.


In block 308, controller 120 determines whether a current data storage capacity and/or an environmental condition has reached a threshold. The threshold for the current data storage capacity can be, for example, a total capacity for the portions of NVM media outside of last resort zone 154 or within a certain percentage of such a total capacity. In some implementations, this can include determining a remaining amount of data capacity available for the portion of the NVM media corresponding to entries 26 or to entries 24 and 26 in translation table 22. In other implementations, the current data storage capacity can include an amount of data stored in the NVM media for the portion of the NVM media corresponding to entries 26 or to entries 24 and 26.


The threshold for an environmental condition can be, for example, a particular temperature or an amount of vibration detected by sensor 142. In other examples, reaching the threshold may require both a certain data storage capacity and a particular environmental condition such as only 95% of the NVM media being available to store data and a temperature of DSD 106 being above a certain operating temperature.


If it is determined in block 308 that the threshold has not been reached, the process will return to block 308 to again determine whether the threshold has been reached. The determination of block 308 may be performed at a fixed interval of time, after certain events of DSD 106, or during idle periods of DSD 106. In some implementations, controller 120 may keep a running total of the current data storage capacity such that the current data storage capacity is updated each time data is stored in the NVM media.


If it is determined that the threshold has been reached in block 308, controller 120 in block 310 sets last resort zone 154 as available for storing data. As discussed above, this can be accomplished by allocating LBAs to last resort zone 154. In block 314, data is written in last resort zone 154 until last resort zone 154 is made available for reuse in block 316. In more detail, last resort zone 154 may be garbage collected or otherwise freed up as part of a maintenance operation of DSD 106. Once last resort zone 154 has been made available for reuse, the process of FIG. 3 returns to block 304 to repeat the process for last resort zone 154.



FIG. 4 is a flowchart for a different data management process that can be performed by controller 120 according to an embodiment. The process of FIG. 4 begins in block 402 with controller 120 optionally assigning last resort zone 154 to a portion of the NVM media of DSD 106. The assignment of last resort zone 154 may occur during an initial startup of DSD 106, a factory testing process of DSD 106, or in the field during operation of DSD 106. In this regard, controller 120 may reassign last resort zone 154 from a default zone to a new zone during operation of DSD 106. In other embodiments, last resort zone 154 may be set by the manufacturer and remain at a fixed location.


In block 404, controller 120 reserves last resort zone 154 as unavailable for storing data. This can be accomplished as noted above with FIG. 2A by allocating LBAs to portions of the NVM media outside of last resort zone 154 without allocating LBAs to last resort zone 154.


In block 406, controller 120 determines a current data storage capacity for the NVM media. In some implementations, this can include determining a remaining amount of data capacity available for the portion of the NVM media corresponding to entries 26 or to entries 24 and 26 in translation table 22. In other implementations, the current data storage capacity can include an amount of data stored in the NVM media for the portion of the NVM media corresponding to entries 26 or to entries 24 and 26.


In block 408, controller 120 determines whether a current data storage capacity and/or an environmental condition has reached a threshold as discussed above with reference to block 308 of FIG. 3.


If it is determined in block 408 that the threshold has not been reached, the process returns to block 406 to determine a new current data storage capacity. The determination of the current data storage capacity in block 406 may be performed at a fixed interval of time, after certain events of DSD 106, or during idle periods of DSD 106. In some implementations, controller 120 may keep a running total of the current data storage capacity such that the current data storage capacity is updated each time data is stored in the NVM media.


If it is determined that the threshold has been reached in block 408, controller 120 in block 410 sets last resort zone 154 as available for storing data. As discussed above, this can be accomplished by allocating LBAs to last resort zone 154.


In block 412, controller 120 optionally adjusts write settings for last resort zone 154. As noted above, this can, for example, include reading data written in last resort zone 154 to verify that the data has been correctly written, changing a track density for last resort zone 154, or adjusting the number of write retires when writing data in last resort zone 154. The type of data allowed to be stored in last resort zone 154 may also be set in block 412, such as restricting the data stored in last resort zone 154 to copies of data stored elsewhere or restricting the data stored in last resort zone 154 to data of a lower priority or lower frequency of access. In other embodiments, data may be written in last resort zone 154 without any adjustment in write settings or type of data allowed to be stored in last resort zone 154.


In block 414, controller 120 controls head 136 to write data in last resort zone 154. After last resort zone 154 is made available for reuse as discussed above for block 316 of FIG. 3, the process of FIG. 4 returns to block 402 to optionally assign last resort zone 154.


Those of ordinary skill in the art will appreciate that the various illustrative logical blocks, modules, and processes described in connection with the examples disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. Furthermore, the foregoing processes can be embodied on a computer readable medium which causes a processor or computer to perform or execute certain functions.


To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, and modules have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Those of ordinary skill in the art may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.


The various illustrative logical blocks, units, modules, and controllers described in connection with the examples disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.


The activities of a method or process described in connection with the examples disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The steps of the method or algorithm may also be performed in an alternate order from those provided in the examples. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable media, an optical media, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an Application Specific Integrated Circuit (ASIC).


The foregoing description of the disclosed example embodiments is provided to enable any person of ordinary skill in the art to make or use the embodiments in the present disclosure. Various modifications to these examples will be readily apparent to those of ordinary skill in the art, and the principles disclosed herein may be applied to other examples without departing from the spirit or scope of the present disclosure. The described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the disclosure is, therefore, indicated by the following claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims
  • 1. A data storage device (DSD) comprising: non-volatile memory (NVM) media including a last resort zone associated with a higher risk of data loss or data corruption than other portions of the NVM media; anda controller configured to:assign the last resort zone to a portion of the NVM media when more than a predetermined number of defects or errors are identified in the portion of the NVM;reserve the last resort zone as unavailable for storing data;determine whether a current data storage capacity and/or an environmental condition for the NVM media has reached a threshold;set the last resort zone as available for storing data if it is determined that the threshold has been reached; andwrite data in the last resort zone.
  • 2. The DSD of claim 1, wherein the NVM media includes a magnetic media.
  • 3. The DSD of claim 1, wherein the NVM media includes a solid state memory.
  • 4. The DSD of claim 1, wherein the controller is further configured to manage access of the NVM media using an address translation table.
  • 5. The DSD of claim 1, wherein the controller is further configured to set the last resort zone as available for storing data by allocating logical addresses to the last resort zone.
  • 6. The DSD of claim 1, wherein the controller is further configured to reserve the last resort zone by allocating logical addresses to portions of the NVM media outside of the last resort zone without allocating logical addresses to the last resort zone.
  • 7. The DSD of claim 1, wherein the NVM media includes a disk and the last resort zone is located on the disk.
  • 8. The DSD of claim 7, wherein the last resort zone is located in an outer diameter portion of the disk.
  • 9. The DSD of claim 8, further comprising a head for reading and writing data on the disk, and wherein the last resort zone is more susceptible to contact by the head than other portions of the disk.
  • 10. The DSD of claim 7, wherein the last resort zone is located in an inner diameter portion of the disk.
  • 11. The DSD of claim 7, wherein the controller is further configured to adjust write settings for writing data in the last resort zone.
  • 12. The DSD of claim 11, wherein each track on the disk includes a plurality of sectors, and wherein the controller is further configured to: attempt to write data in a particular sector of the plurality of sectors for a predetermined number of write retries; andadjust write settings for writing data in the last resort zone by reducing the predetermined number of write retries when attempting to write data in the last resort zone.
  • 13. The DSD of claim 11, wherein the controller is further configured to adjust write settings for writing data in the last resort zone by reading data written in the last resort zone to verify the data written in the last resort zone.
  • 14. The DSD of claim 11, wherein the controller is further configured to adjust write settings for writing data in the last resort zone by changing a track density for writing data in the last resort zone.
  • 15. The DSD of claim 11, wherein the controller is further configured to adjust write settings for writing data in the last resort zone based on whether there is a duplicate copy of the data written in the NVM media outside of the last resort zone.
  • 16. The DSD of claim 1, wherein the data written in the last resort zone includes data accessed with a reading frequency and/or a writing frequency outside of a threshold frequency.
  • 17. The DSD of claim 1, wherein the environmental condition includes at least one of an operating temperature and a vibration condition of the DSD.
  • 18. A method for operating a data storage device (DSD) including non-volatile memory (NVM) media, the method comprising: assigning a last resort zone to a portion of the NVM media when more than a predetermined number of defects or errors are identified in the portion of the NVM, wherein the last resort zone is associated with a higher risk of data loss or data corruption than other portions of the NVM media;reserving the last resort zone of the NVM media as unavailable for storing data;determining whether a current data storage capacity and/or an environmental condition for the NVM media has reached a threshold;setting the last resort zone as available for storing data if it is determined that the threshold has been reached; andwriting data in the last resort zone.
  • 19. The method of claim 18, wherein the NVM media includes a magnetic media.
  • 20. The method of claim 18, wherein the NVM media includes a solid state memory.
  • 21. The method of claim 18, further comprising managing access of the NVM media using an address translation table.
  • 22. The method of claim 18, further comprising setting the last resort zone as available for storing data by allocating logical addresses to the last resort zone.
  • 23. The method of claim 18, further comprising reserving the last resort zone by allocating logical addresses to portions of the NVM media outside of the last resort zone without allocating logical addresses to the last resort zone.
  • 24. The method of claim 18, wherein the NVM media includes a disk and the last resort zone is located on the disk.
  • 25. The method of claim 24, wherein the last resort zone is located in an outer diameter portion of the disk.
  • 26. The method of claim 25, wherein the last resort zone is more susceptible to contact by a head of the DSD than other portions of the disk.
  • 27. The method of claim 24, wherein the last resort zone is located in an inner diameter portion of the disk.
  • 28. The method of claim 24, further comprising adjusting write settings for writing data in the last resort zone.
  • 29. The method of claim 28, wherein the disk includes a plurality of sectors for storing data, and wherein the method further comprises: attempting to write data in a particular sector of the plurality of sectors for a predetermined number of write retries; andadjusting write settings for writing data in the last resort zone by reducing the predetermined number of write retries when attempting to write data in the last resort zone.
  • 30. The method of claim 28, further comprising adjusting write settings for writing data in the last resort zone by reading data written in the last resort zone to verify the data written in the last resort zone.
  • 31. The method of claim 28, further comprising adjusting write settings for writing data in the last resort zone by changing a track density for writing data in the last resort zone.
  • 32. The method of claim 28, further comprising adjusting write settings for writing data in the last resort zone based on whether there is a duplicate copy of the data written in the NVM media outside of the last resort zone.
  • 33. The method of claim 18, wherein the data written in the last resort zone includes data accessed with a reading frequency and/or a writing frequency outside of a threshold frequency.
  • 34. The method of claim 18, wherein the environmental condition includes at least one of an operating temperature and a vibration condition of the DSD.
CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/968,966 , filed on Mar. 21, 2014, which is hereby incorporated by reference in its entirety.

US Referenced Citations (453)
Number Name Date Kind
6018789 Sokolov et al. Jan 2000 A
6065095 Sokolov et al. May 2000 A
6078452 Kittilson et al. Jun 2000 A
6081447 Lofgren et al. Jun 2000 A
6092149 Hicken et al. Jul 2000 A
6092150 Sokolov et al. Jul 2000 A
6094707 Sokolov et al. Jul 2000 A
6105104 Guttmann et al. Aug 2000 A
6111717 Cloke et al. Aug 2000 A
6145052 Howe et al. Nov 2000 A
6175893 D'Souza et al. Jan 2001 B1
6178056 Cloke et al. Jan 2001 B1
6191909 Cloke et al. Feb 2001 B1
6195218 Guttmann et al. Feb 2001 B1
6205494 Williams Mar 2001 B1
6208477 Cloke et al. Mar 2001 B1
6223303 Billings et al. Apr 2001 B1
6230233 Lofgren et al. May 2001 B1
6246346 Cloke et al. Jun 2001 B1
6249393 Billings et al. Jun 2001 B1
6256695 Williams Jul 2001 B1
6262857 Hull et al. Jul 2001 B1
6263459 Schibilla Jul 2001 B1
6272694 Weaver et al. Aug 2001 B1
6278568 Cloke et al. Aug 2001 B1
6279089 Schibilla et al. Aug 2001 B1
6289484 Rothberg et al. Sep 2001 B1
6292912 Cloke et al. Sep 2001 B1
6310740 Dunbar et al. Oct 2001 B1
6317850 Rothberg Nov 2001 B1
6327106 Rothberg Dec 2001 B1
6337778 Gagne Jan 2002 B1
6369969 Christiansen et al. Apr 2002 B1
6384999 Schibilla May 2002 B1
6388833 Golowka et al. May 2002 B1
6405342 Lee Jun 2002 B1
6408357 Hanmann et al. Jun 2002 B1
6408406 Parris Jun 2002 B1
6411452 Cloke Jun 2002 B1
6411458 Billings et al. Jun 2002 B1
6412083 Rothberg et al. Jun 2002 B1
6415349 Hull et al. Jul 2002 B1
6425128 Krapf et al. Jul 2002 B1
6441981 Cloke et al. Aug 2002 B1
6442328 Elliott et al. Aug 2002 B1
6445524 Nazarian et al. Sep 2002 B1
6449767 Krapf et al. Sep 2002 B1
6453115 Boyle Sep 2002 B1
6470420 Hospodor Oct 2002 B1
6480020 Jung et al. Nov 2002 B1
6480349 Kim et al. Nov 2002 B1
6480932 Vallis et al. Nov 2002 B1
6483986 Krapf Nov 2002 B1
6487032 Cloke et al. Nov 2002 B1
6490635 Holmes Dec 2002 B1
6493173 Kim et al. Dec 2002 B1
6499083 Hamlin Dec 2002 B1
6519104 Cloke et al. Feb 2003 B1
6525892 Dunbar et al. Feb 2003 B1
6545830 Briggs et al. Apr 2003 B1
6546489 Frank, Jr. et al. Apr 2003 B1
6550021 Dalphy et al. Apr 2003 B1
6552880 Dunbar et al. Apr 2003 B1
6553457 Wilkins et al. Apr 2003 B1
6578106 Price Jun 2003 B1
6580573 Hull et al. Jun 2003 B1
6594183 Lofgren et al. Jul 2003 B1
6600620 Krounbi et al. Jul 2003 B1
6601137 Castro et al. Jul 2003 B1
6603622 Christiansen et al. Aug 2003 B1
6603625 Hospodor et al. Aug 2003 B1
6604220 Lee Aug 2003 B1
6606682 Dang et al. Aug 2003 B1
6606714 Thelin Aug 2003 B1
6606717 Yu et al. Aug 2003 B1
6611393 Nguyen et al. Aug 2003 B1
6615312 Hamlin et al. Sep 2003 B1
6639748 Christiansen et al. Oct 2003 B1
6647481 Luu et al. Nov 2003 B1
6654193 Thelin Nov 2003 B1
6657810 Kupferman Dec 2003 B1
6661591 Rothberg Dec 2003 B1
6665772 Hamlin Dec 2003 B1
6687073 Kupferman Feb 2004 B1
6687078 Kim Feb 2004 B1
6687850 Rothberg Feb 2004 B1
6690523 Nguyen et al. Feb 2004 B1
6690882 Hanmann et al. Feb 2004 B1
6691198 Hamlin Feb 2004 B1
6691213 Luu et al. Feb 2004 B1
6691255 Rothberg et al. Feb 2004 B1
6693760 Krounbi et al. Feb 2004 B1
6694477 Lee Feb 2004 B1
6697914 Hospodor et al. Feb 2004 B1
6704153 Rothberg et al. Mar 2004 B1
6708251 Boyle et al. Mar 2004 B1
6710951 Cloke Mar 2004 B1
6711628 Thelin Mar 2004 B1
6711635 Wang Mar 2004 B1
6711660 Milne et al. Mar 2004 B1
6715044 Lofgren et al. Mar 2004 B2
6724982 Hamlin Apr 2004 B1
6725329 Ng et al. Apr 2004 B1
6735650 Rothberg May 2004 B1
6735693 Hamlin May 2004 B1
6744772 Eneboe et al. Jun 2004 B1
6745283 Dang Jun 2004 B1
6751402 Elliott et al. Jun 2004 B1
6757481 Nazarian et al. Jun 2004 B1
6772281 Hamlin Aug 2004 B2
6781826 Goldstone et al. Aug 2004 B1
6782449 Codilian et al. Aug 2004 B1
6791779 Singh et al. Sep 2004 B1
6792486 Hanan et al. Sep 2004 B1
6799274 Hamlin Sep 2004 B1
6811427 Garrett et al. Nov 2004 B2
6826003 Subrahmanyam Nov 2004 B1
6826614 Hanmann et al. Nov 2004 B1
6832041 Boyle Dec 2004 B1
6832929 Garrett et al. Dec 2004 B2
6845405 Thelin Jan 2005 B1
6845427 Atai-Azimi Jan 2005 B1
6850443 Lofgren et al. Feb 2005 B2
6851055 Boyle et al. Feb 2005 B1
6851063 Boyle et al. Feb 2005 B1
6853731 Boyle et al. Feb 2005 B1
6854022 Thelin Feb 2005 B1
6862660 Wilkins et al. Mar 2005 B1
6880043 Castro et al. Apr 2005 B1
6882486 Kupferman Apr 2005 B1
6884085 Goldstone Apr 2005 B1
6888831 Hospodor et al. May 2005 B1
6892217 Hanmann et al. May 2005 B1
6892249 Codilian et al. May 2005 B1
6892313 Codilian et al. May 2005 B1
6895455 Rothberg May 2005 B1
6895500 Rothberg May 2005 B1
6898730 Hanan May 2005 B1
6910099 Wang et al. Jun 2005 B1
6928470 Hamlin Aug 2005 B1
6931439 Hanmann et al. Aug 2005 B1
6934104 Kupferman Aug 2005 B1
6934713 Schwartz et al. Aug 2005 B2
6940873 Boyle et al. Sep 2005 B2
6943978 Lee Sep 2005 B1
6948165 Luu et al. Sep 2005 B1
6950267 Liu et al. Sep 2005 B1
6954733 Ellis et al. Oct 2005 B1
6961814 Thelin et al. Nov 2005 B1
6965489 Lee et al. Nov 2005 B1
6965563 Hospodor et al. Nov 2005 B1
6965966 Rothberg et al. Nov 2005 B1
6967799 Lee Nov 2005 B1
6968422 Codilian et al. Nov 2005 B1
6968450 Rothberg et al. Nov 2005 B1
6973495 Milne et al. Dec 2005 B1
6973570 Hamlin Dec 2005 B1
6976190 Goldstone Dec 2005 B1
6983316 Milne et al. Jan 2006 B1
6986007 Procyk et al. Jan 2006 B1
6986154 Price et al. Jan 2006 B1
6995933 Codilian et al. Feb 2006 B1
6996501 Rothberg Feb 2006 B1
6996669 Dang et al. Feb 2006 B1
7002926 Eneboe et al. Feb 2006 B1
7003674 Hamlin Feb 2006 B1
7006316 Sargenti, Jr. et al. Feb 2006 B1
7009820 Hogg Mar 2006 B1
7023639 Kupferman Apr 2006 B1
7024491 Hanmann et al. Apr 2006 B1
7024549 Luu et al. Apr 2006 B1
7024614 Thelin et al. Apr 2006 B1
7027716 Boyle et al. Apr 2006 B1
7028174 Atai-Azimi et al. Apr 2006 B1
7031902 Catiller Apr 2006 B1
7046465 Kupferman May 2006 B1
7046488 Hogg May 2006 B1
7050252 Vallis May 2006 B1
7054937 Milne et al. May 2006 B1
7055000 Severtson May 2006 B1
7055017 Ozaki May 2006 B2
7055167 Masters May 2006 B1
7057836 Kupferman Jun 2006 B1
7062398 Rothberg Jun 2006 B1
7075746 Kupferman Jul 2006 B1
7076604 Thelin Jul 2006 B1
7082494 Thelin et al. Jul 2006 B1
7088538 Codilian et al. Aug 2006 B1
7088545 Singh et al. Aug 2006 B1
7092186 Hogg Aug 2006 B1
7095577 Codilian et al. Aug 2006 B1
7099095 Subrahmanyam et al. Aug 2006 B1
7106537 Bennett Sep 2006 B1
7106947 Boyle et al. Sep 2006 B2
7110202 Vasquez Sep 2006 B1
7111116 Boyle et al. Sep 2006 B1
7114029 Thelin Sep 2006 B1
7120737 Thelin Oct 2006 B1
7120806 Codilian et al. Oct 2006 B1
7126776 Warren, Jr. et al. Oct 2006 B1
7129763 Bennett et al. Oct 2006 B1
7133600 Boyle Nov 2006 B1
7136244 Rothberg Nov 2006 B1
7146094 Boyle Dec 2006 B1
7149046 Coker et al. Dec 2006 B1
7150036 Milne et al. Dec 2006 B1
7155616 Hamlin Dec 2006 B1
7171108 Masters et al. Jan 2007 B1
7171110 Wilshire Jan 2007 B1
7184241 Mallary Feb 2007 B1
7194576 Boyle Mar 2007 B1
7200698 Rothberg Apr 2007 B1
7205805 Bennett Apr 2007 B1
7206497 Boyle et al. Apr 2007 B1
7215496 Kupferman et al. May 2007 B1
7215771 Hamlin May 2007 B1
7237054 Cain et al. Jun 2007 B1
7240161 Boyle Jul 2007 B1
7249365 Price et al. Jul 2007 B1
7263709 Krapf Aug 2007 B1
7274639 Codilian et al. Sep 2007 B1
7274659 Hospodor Sep 2007 B2
7275116 Hanmann et al. Sep 2007 B1
7280302 Masiewicz Oct 2007 B1
7292774 Masters et al. Nov 2007 B1
7292775 Boyle et al. Nov 2007 B1
7296284 Price et al. Nov 2007 B1
7302501 Cain et al. Nov 2007 B1
7302579 Cain et al. Nov 2007 B1
7304816 Johnson et al. Dec 2007 B2
7318088 Mann Jan 2008 B1
7319806 Willner et al. Jan 2008 B1
7325244 Boyle et al. Jan 2008 B2
7330323 Singh et al. Feb 2008 B1
7346790 Klein Mar 2008 B1
7366641 Masiewicz et al. Apr 2008 B1
7369339 Kojima et al. May 2008 B2
7369340 Dang et al. May 2008 B1
7369343 Yeo et al. May 2008 B1
7372650 Kupferman May 2008 B1
7373559 Guha May 2008 B2
7380147 Sun May 2008 B1
7392340 Dang et al. Jun 2008 B1
7404013 Masiewicz Jul 2008 B1
7406545 Rothberg et al. Jul 2008 B1
7415571 Hanan Aug 2008 B1
7436610 Thelin Oct 2008 B1
7437502 Coker Oct 2008 B1
7440214 Ell et al. Oct 2008 B1
7451344 Rothberg Nov 2008 B1
7471483 Ferris et al. Dec 2008 B1
7471486 Coker et al. Dec 2008 B1
7486060 Bennett Feb 2009 B1
7496493 Stevens Feb 2009 B1
7496796 Kubo et al. Feb 2009 B2
7518819 Yu et al. Apr 2009 B1
7526184 Parkinen et al. Apr 2009 B1
7539924 Vasquez et al. May 2009 B1
7543117 Hanan Jun 2009 B1
7551383 Kupferman Jun 2009 B1
7562282 Rothberg Jul 2009 B1
7577973 Kapner, III et al. Aug 2009 B1
7596797 Kapner, III et al. Sep 2009 B1
7599139 Bombet et al. Oct 2009 B1
7619841 Kupferman Nov 2009 B1
7647544 Masiewicz Jan 2010 B1
7649704 Bombet et al. Jan 2010 B1
7653927 Kapner, III et al. Jan 2010 B1
7656603 Xing Feb 2010 B1
7656763 Jin et al. Feb 2010 B1
7657149 Boyle Feb 2010 B2
7672072 Boyle et al. Mar 2010 B1
7673075 Masiewicz Mar 2010 B1
7688540 Mei et al. Mar 2010 B1
7724461 McFadyen et al. May 2010 B1
7725584 Hanmann et al. May 2010 B1
7730295 Lee Jun 2010 B1
7760458 Trinh Jul 2010 B1
7768776 Szeremeta et al. Aug 2010 B1
7804657 Hogg et al. Sep 2010 B1
7813954 Price et al. Oct 2010 B1
7827320 Stevens Nov 2010 B1
7839588 Dang et al. Nov 2010 B1
7843660 Yeo Nov 2010 B1
7852596 Boyle et al. Dec 2010 B2
7859782 Lee Dec 2010 B1
7872822 Rothberg Jan 2011 B1
7898756 Wang Mar 2011 B1
7898762 Guo et al. Mar 2011 B1
7900037 Fallone et al. Mar 2011 B1
7907364 Boyle et al. Mar 2011 B2
7929234 Boyle et al. Apr 2011 B1
7933087 Tsai et al. Apr 2011 B1
7933090 Jung et al. Apr 2011 B1
7934030 Sargenti, Jr. et al. Apr 2011 B1
7940491 Szeremeta et al. May 2011 B2
7944639 Wang May 2011 B1
7945727 Rothberg et al. May 2011 B2
7949564 Hughes et al. May 2011 B1
7974029 Tsai et al. Jul 2011 B2
7974039 Xu et al. Jul 2011 B1
7982993 Tsai et al. Jul 2011 B1
7984200 Bombet et al. Jul 2011 B1
7990648 Wang Aug 2011 B1
7992179 Kapner, III et al. Aug 2011 B1
8004785 Tsai et al. Aug 2011 B1
8006027 Stevens et al. Aug 2011 B1
8014094 Jin Sep 2011 B1
8014977 Masiewicz et al. Sep 2011 B1
8019914 Vasquez et al. Sep 2011 B1
8040625 Boyle et al. Oct 2011 B1
8078943 Lee Dec 2011 B1
8079045 Krapf et al. Dec 2011 B2
8082433 Fallone et al. Dec 2011 B1
8085487 Jung et al. Dec 2011 B1
8089719 Dakroub Jan 2012 B1
8090902 Bennett et al. Jan 2012 B1
8090906 Blaha et al. Jan 2012 B1
8091112 Elliott et al. Jan 2012 B1
8094396 Zhang et al. Jan 2012 B1
8094401 Peng et al. Jan 2012 B1
8116020 Lee Feb 2012 B1
8116025 Chan et al. Feb 2012 B1
8134793 Vasquez et al. Mar 2012 B1
8134798 Thelin et al. Mar 2012 B1
8139301 Li et al. Mar 2012 B1
8139310 Hogg Mar 2012 B1
8144419 Liu Mar 2012 B1
8145452 Masiewicz et al. Mar 2012 B1
8149528 Suratman et al. Apr 2012 B1
8154812 Boyle et al. Apr 2012 B1
8159768 Miyamura Apr 2012 B1
8161328 Wilshire Apr 2012 B1
8164849 Szeremeta et al. Apr 2012 B1
8174780 Tsai et al. May 2012 B1
8190575 Ong et al. May 2012 B1
8194338 Zhang Jun 2012 B1
8194340 Boyle et al. Jun 2012 B1
8194341 Boyle Jun 2012 B1
8201066 Wang Jun 2012 B1
8271692 Dinh et al. Sep 2012 B1
8279550 Hogg Oct 2012 B1
8281218 Ybarra et al. Oct 2012 B1
8285923 Stevens Oct 2012 B2
8289656 Huber Oct 2012 B1
8305705 Roohr Nov 2012 B1
8307156 Codilian et al. Nov 2012 B1
8310775 Boguslawski et al. Nov 2012 B1
8315006 Chahwan et al. Nov 2012 B1
8316263 Gough et al. Nov 2012 B1
8320067 Tsai et al. Nov 2012 B1
8324974 Bennett Dec 2012 B1
8332695 Dalphy et al. Dec 2012 B2
8341337 Ong et al. Dec 2012 B1
8350628 Bennett Jan 2013 B1
8356184 Meyer et al. Jan 2013 B1
8370683 Ryan et al. Feb 2013 B1
8375225 Ybarra Feb 2013 B1
8375274 Bonke Feb 2013 B1
8380922 DeForest et al. Feb 2013 B1
8390948 Hogg Mar 2013 B2
8390952 Szeremeta Mar 2013 B1
8392689 Lott Mar 2013 B1
8407393 Yolar et al. Mar 2013 B1
8413010 Vasquez et al. Apr 2013 B1
8417566 Price et al. Apr 2013 B2
8421663 Bennett Apr 2013 B1
8422172 Dakroub et al. Apr 2013 B1
8427771 Tsai Apr 2013 B1
8429343 Tsai Apr 2013 B1
8433937 Wheelock et al. Apr 2013 B1
8433977 Vasquez et al. Apr 2013 B1
8458526 Dalphy et al. Jun 2013 B2
8462466 Huber Jun 2013 B2
8467151 Huber Jun 2013 B1
8489841 Strecke et al. Jul 2013 B1
8493679 Boguslawski et al. Jul 2013 B1
8498074 Mobley et al. Jul 2013 B1
8499198 Messenger et al. Jul 2013 B1
8512049 Huber et al. Aug 2013 B1
8514506 Li et al. Aug 2013 B1
8531791 Reid et al. Sep 2013 B1
8554741 Malina Oct 2013 B1
8560759 Boyle et al. Oct 2013 B1
8565053 Chung Oct 2013 B1
8576511 Coker et al. Nov 2013 B1
8578100 Huynh et al. Nov 2013 B1
8578242 Burton et al. Nov 2013 B1
8589773 Wang et al. Nov 2013 B1
8593753 Anderson Nov 2013 B1
8595432 Vinson et al. Nov 2013 B1
8599510 Fallone Dec 2013 B1
8601248 Thorsted Dec 2013 B2
8611032 Champion et al. Dec 2013 B2
8612650 Carrie et al. Dec 2013 B1
8612706 Madril et al. Dec 2013 B1
8612798 Tsai Dec 2013 B1
8619383 Jung et al. Dec 2013 B1
8621115 Bombet et al. Dec 2013 B1
8621133 Boyle Dec 2013 B1
8626463 Stevens et al. Jan 2014 B2
8630052 Jung et al. Jan 2014 B1
8630056 Ong Jan 2014 B1
8631188 Heath et al. Jan 2014 B1
8634158 Chahwan et al. Jan 2014 B1
8635412 Wilshire Jan 2014 B1
8640007 Schulze Jan 2014 B1
8654619 Cheng Feb 2014 B1
8661193 Cobos et al. Feb 2014 B1
8667248 Neppalli Mar 2014 B1
8670205 Malina et al. Mar 2014 B1
8683295 Syu et al. Mar 2014 B1
8683457 Hughes et al. Mar 2014 B1
8687306 Coker et al. Apr 2014 B1
8693133 Lee et al. Apr 2014 B1
8694841 Chung et al. Apr 2014 B1
8699159 Malina Apr 2014 B1
8699171 Boyle Apr 2014 B1
8699172 Gunderson et al. Apr 2014 B1
8699175 Olds et al. Apr 2014 B1
8699185 Teh et al. Apr 2014 B1
8700850 Lalouette Apr 2014 B1
8743502 Bonke et al. Jun 2014 B1
8749910 Dang et al. Jun 2014 B1
8751699 Tsai et al. Jun 2014 B1
8755141 Dang Jun 2014 B1
8755143 Wilson et al. Jun 2014 B2
8756361 Carlson et al. Jun 2014 B1
8756382 Carlson et al. Jun 2014 B1
8769593 Elliott et al. Jul 2014 B1
8773802 Anderson et al. Jul 2014 B1
8780478 Huynh et al. Jul 2014 B1
8782334 Boyle et al. Jul 2014 B1
8793532 Tsai et al. Jul 2014 B1
8797669 Burton et al. Aug 2014 B1
8799977 Kapner, III et al. Aug 2014 B1
9042181 Flynn May 2015 B2
20040042105 Cho Mar 2004 A1
20040051988 Jing et al. Mar 2004 A1
20070171798 Wada Jul 2007 A1
20090113702 Hogg May 2009 A1
20100083373 White Apr 2010 A1
20100306551 Meyer et al. Dec 2010 A1
20110002206 Akahoshi Jan 2011 A1
20110226729 Hogg Sep 2011 A1
20120159042 Lott et al. Jun 2012 A1
20120194940 Yoshida Aug 2012 A1
20120275050 Wilson et al. Nov 2012 A1
20120281963 Krapf et al. Nov 2012 A1
20120324980 Nguyen et al. Dec 2012 A1
20130031317 Ryu et al. Jan 2013 A1
20140201424 Chen et al. Jul 2014 A1
20140285922 Ishii Sep 2014 A1
Non-Patent Literature Citations (4)
Entry
Anthony P. Sannino, et al., U.S. Appl. No. 14/260,641, filed Apr. 24, 2014, 18 pages.
Chun Sei Tsai, et al., U.S. Appl. No. 14/227,191, filed Mar. 27, 2014, 25 pages.
Robert M. Fallone, et al., U.S. Appl. No. 14/295,497, filed Jun. 4, 2014 24 pages.
Daniel Bai, “Method of Improving Robustness of HDD by Utilization Prioritization,” Power Point Presentation, Dec. 26, 2013, pp. 1-8.
Related Publications (1)
Number Date Country
20150269964 A1 Sep 2015 US
Provisional Applications (1)
Number Date Country
61968966 Mar 2014 US