Patent Publication Number: US-2023142948-A1

Title: Techniques for managing context information for a storage device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/721,081, entitled “TECHNIQUES FOR MANAGING CONTEXT INFORMATION FOR A STORAGE DEVICE,” filed Sep. 29, 2017, the content of which is incorporated by reference herein in its entirety for all purposes. 
    
    
     FIELD 
     The described embodiments set forth techniques for managing context information for a non-volatile memory (e.g., a solid-state drive (SSD) of a computing device). In particular, the techniques involve segmenting the context information to increase the granularity by which it is transmitted between volatile and non-volatile memories, which can substantially enhance operational efficiency. 
     BACKGROUND 
     Solid state drives (SSDs) are a type of storage device that share a similar footprint with (and provide similar functionality as) traditional magnetic-based hard disk drives (HDDs). Notably, standard SSDs—which utilize “flash” memory—can provide various advantages over standard HDDs, such as considerably faster Input/Output (I/O) performance. For example, average I/O latency speeds provided by SSDs typically outperform those of HDDs because the I/O latency speeds of SSDs are less-affected when data is fragmented across the memory sectors of SSDs. This occurs because HDDs include a read head component that must be relocated each time data is read/written, which produces a latency bottleneck as the average contiguity of written data is reduced over time. Moreover, when fragmentation occurs within HDDs, it becomes necessary to perform resource-expensive defragmentation operations to improve or restore performance. In contrast, SSDs, which are not bridled by read head components, can preserve I/O performance even as data fragmentation levels increase. SSDs also provide the benefit of increased impact tolerance (as there are no moving parts), and, in general, virtually limitless form factor potential. These advantages—combined with the increased availability of SSDs at consumer-affordable prices—make SSDs a preferable choice for mobile devices such as laptops, tablets, and smart phones. 
     Despite the foregoing benefits provided by SSDs, some drawbacks remain that have yet to be addressed. In particular, for a given SSD, the size of the organizational data for managing data stored by the SSD—referred to herein as “context information”—scales directly with the amount of data managed by the SSD. This presents a problem given that the overall storage capacities of SSDs are only increasing with time, thereby leading to increased size requirements for the context information. For example, large-sized context information for a given SSD can lead to performance bottlenecks with regard to both (i) writing the context information (e.g., from a volatile memory) into the SSD, and (ii) restoring the context information when an inadvertent shutdown renders the context information out-of-date. Consequently, there exists a need for an improved technique for managing context information for data stored on SSDs to ensure that acceptable performance metrics remain intact even as the size of the context information scales with the ever-increasing capacities of SSDs. 
     SUMMARY 
     The described embodiments set forth techniques for managing context information for a non-volatile memory (e.g., a solid-state drive (SSD) of a computing device). In particular, the techniques involve partitioning the context information into a collection of “silos” that increase the granularity by which the context information is transferred between volatile and non-volatile memories. In this manner, periodic saves of the context information—as well as restorations of the context information in response to inadvertent shutdowns—can be performed more efficiently. 
     Accordingly, one embodiment sets forth a method for managing context information for data stored within a non-volatile memory of a computing device. According to some embodiments, the method includes the initial steps of (1) loading, into a volatile memory of the computing device, the context information from the non-volatile memory, where the context information is separated into a plurality of silos, and (2) writing transactions into a log stored within the non-volatile memory (e.g., transactions generated by the computing device). Additionally, the method includes performing additional steps each time a particular condition is satisfied, e.g., whenever a threshold number of transactions are processed by the computing device and written into the log. In particular, the additional steps include (3) identifying a next silo of the plurality of silos to be written into the non-volatile memory (i.e., relative to a last-written silo), (4) updating the next silo to reflect the transactions that apply to the next silo, and (5) writing the next silo into the non-volatile memory. 
     Another embodiment sets forth a method for restoring context information when an inadvertent shutdown of a computing device occurs. According to some embodiments, the method can include the steps of (1) identifying the context information within a non-volatile memory of the computing device (e.g., an SSD of the computing device), where the context information is separated into a plurality of silos, and (2) accessing a log stored within the non-volatile memory, where the log reflects a collection of transactions issued by the computing device. Additionally, the method includes performing the following steps for each silo of the plurality of silos: (3) loading the silo into the volatile memory, and (4) in response to identifying, within the log, that at least one transaction (i) applies to the silo, and (ii) occurred after a last write of the silo into the non-volatile memory: updating the silo to reflect the at least one transaction. 
     Other embodiments include a non-transitory computer readable storage medium configured to store instructions that, when executed by a processor included in a computing device, cause the computing device to carry out the various steps of any of the foregoing methods. Further embodiments include a computing device that is configured to carry out the various steps of any of the foregoing methods. 
     Other aspects and advantages of the embodiments described herein will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The included drawings are for illustrative purposes and serve only to provide examples of possible structures and arrangements for the disclosed inventive apparatuses and methods for providing wireless computing devices. These drawings in no way limit any changes in form and detail that may be made to the embodiments by one skilled in the art without departing from the spirit and scope of the embodiments. The embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. 
         FIG.  1    illustrates a block diagram of different components of a system that is configured to implement the various techniques described herein, according to some embodiments. 
         FIGS.  2 A- 2 C  illustrate conceptual diagrams of example scenarios in which different silos can be transmitted, in a unified manner, between a volatile memory and a non-volatile memory by way of direct memory access (DMA), according to some embodiments. 
         FIG.  3    sets forth a conceptual diagram of the manner in which data stored in non-volatile memory can be accessed through logical base addresses (LBAs) using the indirection techniques described herein, according to some embodiments. 
         FIG.  4    illustrates a conceptual diagram of an example scenario that sets forth the manner in which first and second tier entries associated with a given silo can be used to reference data stored within a non-volatile memory, according to some embodiments. 
         FIGS.  5 A- 5 F  provide conceptual diagrams of an example scenario in which the various techniques described herein—i.e., the silo-based partitions and indirection paradigms—can be utilized to improve the overall operational efficiency of a computing device. 
         FIG.  6    illustrates a method for managing context information for data stored within a non-volatile memory of a computing device, according to some embodiments. 
         FIG.  7    illustrates a method for restoring context information when an inadvertent shutdown of a computing device occurs, according to some embodiments. 
         FIG.  8    illustrates a detailed view of a computing device that can be used to implement the various components described herein, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Representative applications of apparatuses and methods according to the presently described embodiments are provided in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the presently described embodiments can be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the presently described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     The embodiments disclosed herein set forth techniques for managing context information for data stored within a non-volatile memory (e.g., a solid-state storage device (SSD)) managed by a computing device. In particular, the techniques involve partitioning the context information into a collection of “silos” in order to increase the granularity by which the context information is transmitted between a volatile memory (e.g., a random-access memory (RAM)) of the computing device and the non-volatile memory of the computing device. For example, direct memory access (DMA) can be utilized to sequentially write different ones of the silos from the volatile memory into the non-volatile memory, which substantially reduces latency in comparison to writing the context information in its entirety. Moreover, when an inadvertent shutdown of the computing device occurs—and the context information is not up-to-date within the non-volatile memory—the silos of which the context information is comprised can be sequentially accessed/restored (e.g., based on logged transactional information), which further reduces latency in comparison to restoring the context information in its entirety. 
       FIG.  1    illustrates a block diagram  100  of a computing device  102 —e.g., a smart phone, a tablet, a laptop, a desktop, a server, etc.—that is configured implement the various techniques described herein. As shown in  FIG.  1   , the computing device  102  can include a processor  104  that, in conjunction with a volatile memory  106  (e.g., a dynamic random access memory (DRAM)) and a storage device  114  (e.g., a solid-state drive (SSD)), enables different software entities to execute on the computing device  102 . For example, the processor  104  can be configured to load, from the storage device  114  into the volatile memory  106 , various components for an operating system (OS)  108 . In turn, the OS  108  can enable the computing device  102  to provide a variety of useful functions, e.g., loading/executing various applications  110  (e.g., user applications). It should be understood that the various hardware components of the computing device  102  illustrated in  FIG.  1    are presented at a high level in the interest of simplification, and that a more detailed breakdown is provided below in conjunction with  FIG.  8   . 
     According to some embodiments, and as shown in  FIG.  1   , the storage device  114  can include a controller  116  that is configured to orchestrate the overall operation of the storage device  114 . For example, the controller  116  can be configured to process input/output (I/O) requests—referred to herein as “transactions”—is sued by the OS  108 /applications  110  to the storage device  114 . According to some embodiments, the controller  116  can include a parity engine for establishing various parity information for the data stored by the storage device  114  to improve overall recovery scenarios. It is noted that the controller  116  can include additional entities that enable the implementation of the various techniques described herein without departing from the scope of this disclosure. It is further noted that these entities can be combined or split into additional entities without departing from the scope of this disclosure. It is additionally noted that the various entities described herein can be implemented using software-based or hardware-based approaches without departing from the scope of this disclosure. 
     In any case, as shown in  FIG.  1   , the storage device  114  can include a non-volatile memory  118  (e.g., flash memory) that is composed of a collection of dies. According to some embodiments, different “bands” can be established within the non-volatile memory  118 , where each band spans the collection of dies. It is noted that one or more of the dies can be reserved by the storage device  114 —e.g., for overprovisioning-based techniques—without departing from the scope of this disclosure, such that a given band can span a subset of the dies that are available within the non-volatile memory  118 . In this regard, the overall “width” of a band can be defined by the number of dies that the band spans. Continuing with this notion, the overall “height” of the band can be defined by a number of “stripes” into which the band is separated. Additionally, and according to some embodiments, each stripe within the band can be separated into a collection of pages, where each page is disposed on a different die of the non-volatile memory  118 . For example, when a given band spans five different dies—and is composed of five different stripes—a total of twenty-five (25) pages are included in the band, where each column of pages is disposed on the same die. In this manner, the data within a given band can be separated across the non-volatile memory  118  in a manner that enables redundancy-based protection to be established without significantly impacting the overall performance of the storage device  114 . 
     As shown in  FIG.  1   , the aforementioned bands managed by the storage device  114  can include a log band  120 , an indirection band  122 , and a data band  124 . According to some embodiments, transactional information associated with the indirection band  122 /data band  124 —e.g., details associated with I/O requests processed by the controller  116 —can be written into the log band  120 . As described in greater detail herein, this transactional information can be utilized to restore the content of the indirection band  122  when an inadvertent shutdown of the computing device  102  renders at least a portion of the content out-of-date. 
     According to some embodiments, the content stored in the indirection band  122  can include context information  112  that serves as a mapping table for data that is stored within the data band  124 . As shown in  FIG.  1   , the context information  112  can be transmitted between the volatile memory  106  and the non-volatile memory  118  using direct memory access (DMA)  150 . In particular, the DMA  150  can enable the processor  104  to play little or no role in the data transmissions between the volatile memory  106  and the non-volatile memory  118 , which can improve efficiency. It is noted, however, that any technique can be utilized to transmit data between the volatile memory  106  and the non-volatile memory  118  without departing from the scope of this disclosure. In any case, as shown in  FIG.  1   , the context information  112  can be segmented into a collection of silos  130 , which, as described in greater detail herein, increases the granularity by which the context information  112  can be transmitted between the volatile memory  106  and the non-volatile memory  118 . According to some embodiments, and as shown in  FIG.  1   , each silo  130  can include metadata  132  and a context information subset  134 . According to some embodiments, the metadata  132  for a given silo  130  can include descriptive information about the silo  130 , e.g., an index of the silo  130  (relative to the other silos  130 ), a size of the silo  130 , and so on. Additionally, the context information subset  134  for a given silo  130  can include a respective portion of the context information  112  to which the silo  130  corresponds. 
     According to some embodiments, and as described in greater detail herein, the context information  112  can be organized into a hierarchy that includes first and second depth levels. In particular, the first depth level can correspond to a collection of first-tier entries, while the second depth level can correspond to a collection of second-tier entries. According to some embodiments, the first and second-tier entries can store data in accordance with different encoding formats that coincide with the manner in which the non-volatile memory  118  is partitioned into different sectors. For example, when each sector represents a 4 KB sector of memory, each first-tier entry can correspond to a contiguous collection of two hundred fifty-six (256) sectors. In this regard, the value of a given first-tier entry can indicate whether the first-tier entry (1) directly refers to a physical location (e.g., an address of a starting sector) within the non-volatile memory  118 , or (2) directly refers (e.g., via a pointer) to one or more second-tier entries. According to some embodiments, when condition (1) is met, it is implied that all (e.g., the two-hundred fifty-six (256)) sectors associated with the first-tier entry are contiguously written, which can provide a compression ratio of 1/256. More specifically, this compression ratio can be achieved because the first-tier entry stores a pointer to a first sector of the two hundred fifty-six (256) sectors associated with the first-tier entry, where no second-tier entries are required. Alternatively, when condition (2) is met, information included in the first-tier entry indicates (i) one or more second-tier entries that are associated with the first-tier entry, as well as (ii) how the information in the one or more second-tier entries should be interpreted. Using this approach, each second-tier entry can refer to one or more sectors, thereby enabling data to be disparately stored across the sectors of the non-volatile memory  118 . A more detailed description of the first-tier entries and second-tier entries is provided below in conjunction with  FIGS.  3 - 4   . 
     Accordingly,  FIG.  1    provides high-level overview of the manner in which the computing device  102  can be configured to implement the techniques described herein. A more detailed explanation of these techniques will now be provided below in conjunction with  FIGS.  2 A- 2 C,  3 - 4 ,  5 A- 5 F, and  6 - 8   . 
       FIGS.  2 A- 2 C  illustrate conceptual diagrams of example scenarios in which different silos  130  can be transmitted, in a unified manner, between the volatile memory  106  and the non-volatile memory  118  by way of direct memory access  150 , according to some embodiments. In particular,  FIGS.  2 A- 2 C  illustrate that the context information subset  134  of a given silo  130 —i.e., the first and second-tier entries that correspond to the silo  130 —can be separately-stored from one another, yet remain capable of being transmitted between the volatile memory  106  and the non-volatile memory  118  in a unified manner. In other words, the techniques set forth herein enable the context information subset  134  of the silo  130  to be transmitted between the volatile memory  106  and the non-volatile memory  118  in the form of a snapshot-like image despite representing only a portion of the context information  112 . 
     According to some embodiments, and as shown in  FIG.  2 A , a Tier 1 space  202  can be configured to store the different first-tier entries that correspond to the silos  130 . In particular, the Tier 1 space  202  can be configured to represent a span of logical base addresses (LBAs), where the first-tier entries of each silo  130  correspond to a respective portion of the LBAs. For example, when the context information  112  is separated into thirty-two (32) different silos  130 , each silo  130  can correspond to a respective 1/32 of the LBAs. In this regard, the Tier 1 space  202  can be fixed in size, whereas a Tier 2 space  204  can be dynamically expanded/contracted to accommodate second-tier entries as they are established/removed over time. Notably, it is important to ensure that the context information subset  134  for a given silo  130 —which includes first and second-tier entries—can continue to be transmitted in a unified operation even as the Tier 2 space  204  fluctuates over time. To achieve this result, the embodiments can involve expanding the Tier 2 space  204  for all silos  130  even when only a single silo  130  is seeking to store additional second-tier entries (e.g., that cannot fit within existing Tier 2 space  204 ). For example, as indicated in  FIG.  2 A , adding a new column into the Tier 2 space  204  effectively expands the Tier 2 space  204  for all of the silos  130 . Similarly, when a particular column in the Tier 2 space  204  is no longer needed—e.g., when all second-tier entries for all of the silos  130  are eliminated (e.g., through data deletions, defragmentation operations, etc.)—the column can be removed from the Tier 2 space  204 . 
     In any case, in  FIG.  2 A , a first example can involve transmitting the silo  130 - 0 —specifically, the context information subset  134 - 0  of the silo  130 - 0 —between the volatile memory  106  and the non-volatile memory  118  using direct memory access  150 . In particular, the first example can involve transmitting, in a unified manner, (1) the first-tier entries associated with the silo  130 - 0 —illustrated in  FIG.  2 A  as Silo_ 0  Tier 1 entries  208 - 0 —and (2) the second-tier entries associated with the silo  130 - 0 —illustrated in  FIG.  2 A  as Silo_ 0  Tier 2 entries  210 - 0 . According to some embodiments, the overall layout of the context information subset  134  (i.e., Silo_ 0  Tier 1 entries  208 - 0 /Silo_ 0  Tier 2 entries  210 - 0 ) can be maintained when transmitted between the volatile memory  106  and the non-volatile memory  118  such that little operational overhead is required. For example, when written from the volatile memory  106  into the non-volatile memory  118 , the context information subset  134 - 0  (of the silo  130 - 0 ) can be written into a corresponding area of the context information  112  in the indirection band  122  without requiring a reorganization/reformatting of the context information subset  134 - 0 . Conversely, when read from the non-volatile memory  118  into the volatile memory  106 , the context information subset  134 - 0  can be written into an available area of the volatile memory  106  (e.g., allocated for the context information  112 ) without requiring a reorganization/reformatting of the context information subset  134 - 0 . In this manner, the silos  130  can be transmitted between the volatile memory  106  and the non-volatile memory  118  in a unified/snapshot-like manner, thereby substantially enhancing efficiency. Moreover, the direct memory access  150  techniques described herein can enable both the volatile memory  106  and the non-volatile memory  118  to directly-transmit the context information subsets  134  of the silos  130  between one another without requiring intensive involvement of the processor  104 , thereby further enhancing operational efficiency. 
     Additionally,  FIGS.  2 B- 2 C  provide further examples of silo  130  transfers between the volatile memory  106  and the non-volatile memory  118 . In particular,  FIGS.  2 B- 2 C  further-convey the notion that the context information subsets  134  of different silos  130  can be separately stored from one another, yet remain capable of being transmitted between the volatile memory  106  and the non-volatile memory  118  in a unified manner. For example,  FIG.  2 B  illustrates an additional example that involves transmitting the silo  130 - 1 —specifically, the context information subset  134 - 1  of the silo  130 - 1 —between the volatile memory  106  and the non-volatile memory  118  using direct memory access  150 . Further,  FIG.  2 C  illustrates another example that involves transmitting the silo  130 -J—specifically, the context information subset  134 -J of the silo  130 -J—between the volatile memory  106  and the non-volatile memory  118  using direct memory access  150 . 
     Accordingly,  FIGS.  2 A- 2 C  illustrate conceptual diagrams of example scenarios in which different silos  130  can be transmitted, in a unified manner, between the volatile memory  106  and the non-volatile memory  118  by way of direct memory access  150 , according to some embodiments. It is noted that direct memory access  150  is not a requirement of the embodiments set forth herein, and that any approach can be utilized when transferring the silos  130  between the volatile memory  106  and the non-volatile memory  118 . 
       FIG.  3    sets forth a conceptual diagram  300  of the manner in which data stored in non-volatile memory  118  (e.g., in the data band  124 ) can be accessed through logical base addresses (LBAs) using the indirection techniques described herein, according to some embodiments. In particular, and as shown in  FIG.  3   , an example LBA encoding scheme  302  can include a Tier 1 index  304 , a silo index  306 , and a Tier 1 offset  308 . It is noted that the number of bits allocated to each of the Tier 1 index  304 , the silo index  306 , and the Tier 1 offset  308  are not drawn to scale in  FIG.  3   , and that these values can be assigned any number of bits without departing from the scope of this disclosure. In any case, as shown in  FIG.  3   , the Tier 1 index  304 /silo index  306  can collectively refer to a particular group of first-tier entries (e.g., Silo_ 0  Tier 1 entries  208 - 0 ) associated with a particular silo  130 , and the Tier 1 offset  308  can refer to a particular first-tier entry within the particular group of first-tier entries (e.g., Silo_ 0  Tier 1 entry  208 - 0 - 0 ). As previously described herein, and as illustrated in  FIG.  3   , each first-tier entry can refer to a physical location (e.g., via an address of a starting sector) within the non-volatile memory  118 . Alternatively, and as illustrated in  FIG.  3   , each first-tier entry can refer to at least one second-tier entry (e.g., the Silo_ 0  Tier 2 entry  210 - 0 - 0 - 0  within the Silo_ 0  Tier 2 entries  210 - 0 - 0 ), where each second-tier entry can refer to one or more sectors of the non-volatile memory  118 . 
     It is noted that a more detailed breakdown of various indirection techniques that can be utilized by the embodiments set forth herein can be found in U.S. patent application Ser. No. 14/710,495, filed May 12, 2015, entitled “METHODS AND SYSTEM FOR MAINTAINING AN INDIRECTION SYSTEM FOR A MASS STORAGE DEVICE,” the content of which is incorporated by reference herein in its entirety. 
     To provide additional understanding of the indirection techniques described herein,  FIG.  4    illustrates a conceptual diagram  400  of an example scenario that sets forth the manner in which first and second tier entries associated with a given silo  130 —in particular, the silo  130 - 0 —can be used to reference data stored within different sectors  402  of the non-volatile memory  118 , according to some embodiments. In particular, and as shown in  FIG.  4   , several Silo_ 0  Tier 1 entries  208 - 0  associated with the silo  130 - 0  are depicted, where at least one of the Silo_ 0  Tier 1 entries  208 - 0 —in particular, the Silo_ 0  Tier 1 entry  208 - 0 - 5 —does not reference any Silo_ 0  Tier 2 entries  210 - 0 - 0 . Instead, the Silo_ 0  Tier 1 entry  208 - 0 - 5  directly-references a particular sector  402  of the non-volatile memory  118 . According to this example, the Silo_ 0  Tier 1 entry  208 - 0 - 5  can represent a pass-through first-tier entry that corresponds to a contiguous span of sectors  402  (as previously described herein). As also illustrated in  FIG.  4   , at least one of the Silo_ 0  Tier 1 entries  208 - 0 —in particular, the Silo_ 0  Tier 1 entry  208 - 0 - 1 —references at least one of the Silo_ 0  Tier 2 entries  210 - 0 - 0 —in particular, the Silo_ 0  Tier 2 entry  210 - 0 - 0 - 0 . In this regard, the Silo_ 0  Tier 2 entry  210 - 0 - 0 - 0 —along with any other Silo_ 0  Tier 2 entries  210 - 0 - 0  that correspond to the Silo_ 0  Tier 1 entry  208 - 0 - 1 —establish an indirect reference between the Silo_ 0  Tier 1 entry  208 - 0 - 1  and at least one sector  402  of the non-volatile memory  118 . Accordingly, indirection techniques described herein enable each LBA to refer to content stored in the non-volatile memory  118  through only one or two levels of hierarchy, thereby providing a highly-efficient architecture on which the various techniques described herein can be implemented. 
     At this juncture,  FIGS.  5 A- 5 F  provide conceptual diagrams of an example scenario in which the various techniques described herein—i.e., the silo-based partitions and indirection paradigms—can be utilized to improve the overall operational efficiency of the computing device  102 . In particular, the example scenario illustrated in  FIGS.  5 A- 5 B  involves efficiently writing four (4) of six (6) total silos  130  from the volatile memory  106  into the non-volatile memory  118  as transactions are received and carried out by the controller  116 . Moreover, the example scenario illustrated in  FIGS.  5 C- 5 F  involves the controller  116  (1) encountering an inadvertent shutdown that compromises the overall coherency of the six silos  130  in the non-volatile memory  118 , and (2) efficiently carrying out a procedure to restore the coherency of the six silos  130 . It is noted that the example scenario set forth in  FIGS.  5 A- 5 F  involves six silos  130  in the interest of simplifying this disclosure, and that any number of silos  130  can be implemented without departing from the scope of this disclosure. 
     To provide a detailed understanding of the circular manner in which the silos  130  are written from the volatile memory  106  into the non-volatile memory  118 , a first step in  FIG.  5 A  occurs after previous transactions  501  are processed and cause the silo  130 - 5  to be the last-written silo  130  from the volatile memory  106  to the non-volatile memory  118 . In this regard, the silo  130 - 4  is the last-written silo  130  relative to the silo  130 - 5 , the silo  130 - 3  is the last-written silo  130  relative to silo  130 - 4 , and so on. In this manner, a round-robin approach is utilized such that a successive silo  130  (relative to a previous silo  130 ) is written from the volatile memory  106  into the non-volatile memory  118  in accordance with different conditions being met, e.g., a threshold number of transactions being received, an amount of time lapsing, a particular functionality being executed (e.g., garbage collection, defragmentation, etc.), and the like. 
     Accordingly, and as shown in  FIG.  5 A , the first step involves the controller  116  receiving and processing a number of transactions  502 . As previously noted herein, each transaction can represent one or more I/O requests that are directed toward the storage device  114 . For example, a transaction  502  can involve writing, modifying, or removing data from the data band  124  within the non-volatile memory  118 . It is noted that the foregoing example is not meant to be limiting, and that the transactions described herein encompass any form of I/O operation(s) directed toward the non-volatile memory  118  of the storage device  114 . As shown in  FIG.  5 A , transactional information associated with each of the transactions  502  can be recorded within the log band  120  within the non-volatile memory  118 . According to some embodiments, the transactional information can include pointers to the context information  112  stored within the indirection band  122 . In particular, these pointers can enable an efficient restoration of the context information  112  to be carried out in response to inadvertent shutdowns of the computing device  102 , the details of which are described below in conjunction with  FIGS.  5 C- 5 F . According to some embodiments, different log files can be managed within the log band  120 , and can be used to store transactional information associated with the transactions as they are processed. Moreover, redundant copies of log file portions can be stored within the log band  120 , thereby improving the efficacy of recovery procedures even when severe failure events take place. For example, for each log file portion stored on a first die of the non-volatile memory  118 , a copy of the log file portion can be stored on a second (i.e., different) die of the non-volatile memory  118 . In this manner, each log file portion can be recovered even when the first or the second die fails within the non-volatile memory  118 . 
     As shown in  FIG.  5 A , the controller  116  can be configured to carry out a context save  504  in response to identifying that a threshold number of transactions have been processed. It is noted, however, that the controller  116  can be configured to carry out context saves in response to other conditions being satisfied. For example, the controller  116  can be configured to periodically carry out context saves regardless of the number of transactions that have been processed. In another example, the controller  116  can be configured to carry out context saves in response to different types of events being completed, e.g., garbage collection events, defragmentation events, and so on. It is noted that the foregoing examples are not meant to represent an exhaustive list, and that any number of conditions, associated with any aspects of the operation of the computing device  102 , can cause the controller  116  to carry out context saves described herein. 
     In any case, as shown in  FIG.  5 A , the context save  504  can involve (1) updating the silo  130 - 0  to reflect the transactions  502 , and (2) writing the silo  130 - 0  from the volatile memory  106  into the non-volatile memory  118 . In particular, and as previously described above in conjunction with  FIGS.  2 A- 2 C , writing the silo  130 - 0  can involve transmitting all or a portion of the information associated with the silo  130 - 0 , e.g., the metadata  132 - 0 , the context information subset  134 - 0 , etc., into a corresponding area within the context information  112  stored within the indirection band  122 . According to some embodiments, the silo  130 - 0  can be placed into a locked state prior to the silo  130 - 0  being updated/written from the volatile memory  106  into the non-volatile memory  118  to ensure that the state of the silo  130 - 0  is not inappropriately modified. Additionally, the context save  504  can involve writing information into the log band  120  to indicate whether the silo  130 - 0  was successfully written into the non-volatile memory  118 . For example, when the silo  130 - 0  is successfully written from the volatile memory  106  to the non-volatile memory  118 , the controller  116  can generate a key that corresponds to the silo  130 - 0 , and place the key into the log band  120 . In this manner, the log band  120  can be parsed at a later time to identify the last-written silo  130  among the silos  130 . As described below in greater detail in conjunction with  FIGS.  5 C- 5 F , the indication of the last-written silo  130  enables the recovery techniques described herein to be implemented in an efficient manner. 
     Additionally, the second step illustrated in  FIG.  5 A —as well as the third and fourth steps illustrated in  FIG.  5 B —provide additional understanding for the silo  130  write techniques set forth herein. For example, the second step in  FIG.  5 A  involves (1) writing transactions  506  into the log band  120 , and (2) in accordance with a context save  508 , updating the silo  130 - 1 /writing the silo  130 - 1  from the volatile memory  106  into the non-volatile memory  118 . Additionally, the third step of  FIG.  5 B  involves (1) writing transactions  510  into the log band  120 , and (2) in accordance with a context save  512 , updating the silo  130 - 2 /writing the silo  130 - 2  from the volatile memory  106  into the non-volatile memory  118 . Further, the fourth step of  FIG.  5 B  involves (1) writing transactions  514  into the log band  120 , and (2) in accordance with a context save  516 , updating the silo  130 - 3 /writing the silo  130 - 3  from the volatile memory  106  into the non-volatile memory  118 . 
     Accordingly, the various steps illustrated in  FIGS.  5 A- 5 B  provide a detailed understanding of the benefits that can be achieved through segmenting the context information  112  when writing the context information  112  from the volatile memory  106  into the non-volatile memory  118 . As previously described herein, these benefits can also apply to recovery scenarios in which the context information  112  is rendered out-of-date and needs to be restored in accordance with the transaction information stored in the log band  120 . For example, an inadvertent shutdown of the computing device  102  can cause a scenario in which (1) at least one transaction that affects a particular silo  130  has been written into the log band  120 , and (2) the silo  130  has not been written from the volatile memory  106  into the non-volatile memory  118 . In this scenario, the silo  130  stored within the non-volatile memory  118  is out-of-date, as the state of the silo  130  does not appropriately reflect the at least one transaction. Accordingly, it is necessary to restore the silo  130  to an up-to-date state (in accordance with the at least one transaction) to ensure that the storage device  114 —and the computing device  102  as a whole—are operating correctly. 
     Accordingly,  FIG.  5 C  continues the example scenario illustrated in  FIGS.  5 A- 5 B , and involves a fifth step in which an inadvertent shutdown  520  of the computing device  102  occurs (1) after transactions  518  are written into the log band  120 , but (2) before the silo  130 - 4  is written from the volatile memory  106  into the non-volatile memory  118 . In turn, a sixth step illustrated in  FIG.  5 C  involves the controller  116  initializing a recovery procedure (e.g., during a boot, reboot, wakeup, etc., of the computing device  102 ) to restore the context information  112 . In particular, and as shown in  FIG.  5 C , the sixth step involves the controller  116  identifying that the silo  130 - 3  was the last silo  130  that was written from the volatile memory  106  into the non-volatile memory  118 . For example, as previously described above, the controller  116  can reference the log band  120 —e.g., the transaction logs, the keys stored therein, etc.—to identify that the silo  130 - 3  was the last-written silo  130 . In turn, to carry out the recovery procedure, the controller  116  can load the silo  130 - 4  into the volatile memory  106 . In particular, the controller  116  loads the silo  130 - 4  because the silo  130 - 4  is the most out-of-date silo  130  relative to the other silos  130 , with the assumption that the silos  130  are written in a sequential, circular, and repetitive fashion (e.g., as described in  FIGS.  5 A- 5 B ). In this regard, it can be efficient to restore the silo  130 - 4  first, as it can be likely that the silo  130 - 4  will require the most updates relative to the other silos  130 . 
     Accordingly, as shown in  FIG.  5 C —and after the silo  130 - 4  is loaded into the volatile memory  106 —the controller  116  can identify, e.g., within the transaction information stored in the log band  120 —any transactions that (1) apply to the silo  130 - 4 , and (2) occurred after the silo  130 - 4  was last-written from the volatile memory  106  into the non-volatile memory  118 . In turn, if the controller  116  identifies any transactions using the foregoing criteria, the controller  116  can “replay” the transactions against the silo  130 - 4 —in particular, the context information subset  134 - 4  of the silo  130 - 4 —in accordance with the transactions. This can involve, for example, updating first/second tier entries included in the context information subset  134 - 4  so that they reference the appropriate areas of the non-volatile memory  118  (in accordance with the transactions). 
     According to some embodiments, when the transactions have been effectively replayed, the silo  130 - 4  is in an up-to-date state, and the silo  130 - 4  can optionally be written from the volatile memory  106  into the non-volatile memory  118 . Additionally, the transaction information stored in the log band  120  can be updated to reflect that the silo  130 - 4  has been successfully written. In this manner, if another inadvertent shutdown occurs during the recovery procedure, the same updates made to the silo  130 - 4  during the restoration of the sixth step of  FIG.  5 C  will not need to be carried out again, thereby increasing efficiency. Alternatively, the silo  130 - 4  will be written from the volatile memory  106  into the non-volatile memory  118  in due course, e.g., when the computing device  102  resumes normal operation after the recovery procedure is completed. 
     In any case, at this juncture, it is noted that the transactions that occurred after the silo  130 - 3  was written from the volatile memory  106  into the non-volatile memory  118  can potentially apply to one or more of the remaining five silos  130 - 5 ,  130 - 0 ,  130 - 1 ,  130 - 2 , and  130 - 3 . Accordingly,  FIGS.  5 D- 5 F  illustrate steps seven through eleven of the recovery procedure, which involve restoring each of the remaining five silos  130 - 5 ,  130 - 0 ,  130 - 1 ,  130 - 2 , and  130 - 3 . For example, step seven illustrated in  FIG.  5 D  illustrates a recovery procedure for the silo  130 - 5  that is carried out by the controller  116 . Additionally, step eight illustrated in  FIG.  5 D  illustrates a recovery procedure for the silo  130 - 0  that is carried out by the controller  116 . Additionally, step nine illustrated in  FIG.  5 E  illustrates a recovery procedure for the silo  130 - 1  that is carried out by the controller  116 . Additionally, step ten illustrated in  FIG.  5 E  illustrates a recovery procedure for the silo  130 - 2  that is carried out by the controller  116 . Additionally, step eleven illustrated in  FIG.  5 F  illustrates a recovery procedure for the silo  130 - 3  that is carried out by the controller  116 . In turn, at step twelve illustrated in  FIG.  5 F , each of the six silos  130  have been properly restored, whereupon the computing device  102 /storage device  114  can enter back into a normal operating mode and process new transactions  550 . 
     Accordingly,  FIGS.  5 A- 5 F  provide conceptual diagrams of an example scenario in which the various techniques described herein—i.e., the silo-based partitions and indirection paradigms—can be utilized to improve the overall operational efficiency of the computing device  102 . To provide further context,  FIGS.  6 - 7    illustrate method diagrams that can be carried out to implement the various techniques described herein, which will now be described below in greater detail. 
       FIG.  6    illustrates a method  600  for managing context information for data stored within a non-volatile memory of a computing device, according to some embodiments. As shown in  FIG.  6   , the method  600  begins at step  602 , and involves loading context information into a volatile memory (of the computing device) from the non-volatile memory, where the context information is separated into a plurality of silos (e.g., as described above in conjunction with  FIGS.  2 A- 2 C ). Step  604  involves writing transactions into a log stored within the non-volatile memory (e.g., as described above in conjunction with  FIGS.  5 A- 5 B ). Step  606  involves determining whether at least one condition is satisfied (e.g., the conditions described above in conjunction with  FIG.  5 A ). If, at step  606 , it is determined that condition is satisfied, then the method  600  proceeds to step  608 . Otherwise, the method  600  proceeds back to step  604 , where transactions are received/written into the log (until the at least one condition is satisfied). 
     Step  608  involves identifying a next silo of the plurality of silos to be written into the non-volatile memory (e.g., as described above in conjunction with  FIGS.  5 A- 5 B ). Step  610  involves updating the next silo to reflect the transactions that apply to the next silo (e.g., as described above in conjunction with  FIGS.  5 A- 5 B ). Step  612  involves writing the next silo into the non-volatile memory (e.g., as described above in conjunction with  FIGS.  5 A- 5 B ). In turn, the method can return to step  604 , such that the silos are updated in a round-robin fashion in accordance with the transactions that are processed. 
       FIG.  7    illustrates a method  700  for restoring context information when an inadvertent shutdown of a computing device occurs, according to some embodiments. As shown in  FIG.  7   , the method  700  begins at step  702 , and involves identifying, during a startup procedure (e.g., a boot, a reboot, a wakeup, etc.), context information within a non-volatile memory, where the context information is separated into a plurality of silos (e.g., as described above in conjunction with  FIGS.  2 A- 2 C ). Step  704  involves accessing a log stored within the non-volatile memory (e.g., as described above in conjunction with  FIGS.  5 C- 5 F ). Step  706  involves carrying out steps  708 - 714  for each silo of the plurality of silos. In particular, step  708  involves loading the silo into the volatile memory (e.g., as described above in conjunction with  FIGS.  5 C- 5 F ). In turn, step  710  involves determining whether at least one transaction in the log (i) applies to the silo, and (ii) occurred after a last write of the silo into the non-volatile memory (e.g., as described above in conjunction with  FIGS.  5 C- 5 F ). If, at step  710 , it is determined that at least one transaction in the log (i) applies to the silo, and (ii) occurred after a last write of the silo into the non-volatile memory, then the method  700  proceeds to step  712 . Otherwise, the method  700  proceeds back to step  706 , which involves processing a next silo (if any) of the plurality of silos, or the method  700  ends. Step  712  involves updating the silo to reflect the at least one transaction (e.g., as described above in conjunction with  FIGS.  5 C- 5 F ). At step  714 , the controller  116  writes the silo into the non-volatile memory (e.g., as described above in conjunction with  FIGS.  5 C- 5 F ). In turn, the method can proceed back to step  706 , which involves processing a next silo (if any) of the plurality of silos, or ending the method  700 . 
     It is noted that this disclosure primarily involves the controller  116  carrying out the various techniques described herein for the purpose of unified language and simplification. However, it is noted that other entities can be configured to carry out these techniques without departing from this disclosure. For example, other software components (e.g., the OS  108 , applications  110 , firmware(s), etc.) executing on the computing device  102  can be configured to carry out all or a portion of the techniques described herein without departing from the scope of this disclosure. Moreover, other hardware components included in the computing device  102  can be configured to carry out all or a portion of the techniques described herein without departing from the scope of this disclosure. Further, all or a portion of the techniques described herein can be offloaded to another computing device without departing from the scope of this disclosure. 
       FIG.  8    illustrates a detailed view of a computing device  800  that can be used to implement the various components described herein, according to some embodiments. In particular, the detailed view illustrates various components that can be included in the computing device  102  illustrated in  FIG.  1   . As shown in  FIG.  8   , the computing device  800  can include a processor  802  that represents a microprocessor or controller for controlling the overall operation of computing device  800 . The computing device  800  can also include a user input device  808  that allows a user of the computing device  800  to interact with the computing device  800 . For example, the user input device  808  can take a variety of forms, such as a button, keypad, dial, touch screen, audio input interface, visual/image capture input interface, input in the form of sensor data, etc. Still further, the computing device  800  can include a display  810  (screen display) that can be controlled by the processor  802  to display information to the user. A data bus  816  can facilitate data transfer between at least a storage device  840 , the processor  802 , and a controller  813 . The controller  813  can be used to interface with and control different equipment through and equipment control bus  814 . The computing device  800  can also include a network/bus interface  811  that couples to a data link  812 . In the case of a wireless connection, the network/bus interface  811  can include a wireless transceiver. 
     The computing device  800  also includes a storage device  840 , which can comprise a single disk or a plurality of disks (e.g., SSDs), and includes a storage management module that manages one or more partitions within the storage device  840 . In some embodiments, storage device  840  can include flash memory, semiconductor (solid state) memory or the like. The computing device  800  can also include a Random-Access Memory (RAM)  820  and a Read-Only Memory (ROM)  822 . The ROM  822  can store programs, utilities or processes to be executed in a non-volatile manner. The RAM  820  can provide volatile data storage, and stores instructions related to the operation of the computing device  102 . 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, DVDs, magnetic tape, hard disk drives, solid state drives, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.