A data storage device includes a non-volatile memory (NVM) device and a controller coupled to the NVM device. The controller is configured to create a bad block table that tracks bad blocks of the NVM device, send the bad block table to a host memory location, and check the bad block table to determine whether a block to be read or written to is bad. The controller is further configured to request information on a bad block from the bad block table located in the host memory location, determine that the requested information is not available from the host memory location, and retrieve the requested information from a location separate from the host memory location. A sum of the times to generate a request to check the flat relink table, execute the request, and retrieve the requested information is less than a time to process a host command.

A computer system stores metadata that is used to identify physical memory devices that store randomly-accessible data for memory of the computer system. In one approach, access to memory in an address space is maintained by an operating system of the computer system. Stored metadata associates a first address range of the address space with a first memory device, and a second address range of the address space with a second memory device. The operating system manages processes running on the computer system by accessing the stored metadata. This management includes allocating memory based on the stored metadata so that data for a first process is stored in the first memory device, and data for a second process is stored in the second memory device.

An electronic device may include a processor, a first volatile memory, and a storage including a nonvolatile memory and a second volatile memory. The processor may be configured to: identify information of a specific file and a kind of a request for data included in the specific file in response to a creation of the request for the data, set a flag in the request based on the identified information of the specific file, identify whether mapping information of a specific region including a logical address of the data among mapping information in which logical addresses and physical addresses for the nonvolatile memory are mapped onto each other is stored in the first volatile memory, determine whether to manage the mapping information of the specific region using the first volatile memory, and determine whether to update the mapping information of the specific region in the first volatile memory.

A variety of applications can include systems and methods that utilize a hybrid logical to physical (L2P) caching scheme. A L2P cache and a L2P changelog in a storage device can be controlled for use in write and read operations of a memory system. A page pointer table in the L2P cache can be accessed, for performance of a write operation in the memory system, to obtain a specific physical address mapped to a specified logical block address from a host, where the access is based on the page pointer table loaded into the L2P cache from the L2P changelog. The L2P cache area can be progressively configured with the most frequently accessed page pointer tables in the L2P changelog in the latest host accesses.

Cache line data and metadata are compressed and stored in first and, optionally, second memory regions, the metadata including an address tag When the compressed data fit entirely within a primary block in the first memory region, both data and metadata are retrieved in a single memory access. Otherwise, overflow data is stored in an overflow block in the second memory region. The first and second memory regions may be located in the same row of a DRAM, for example, or in different regions of a DRAM and may be configured to enable standard DRAM components to be used. Compression and decompression logic circuits may be included in a memory controller.

A method for compressing is provided. The method including receiving a block of data to store on at least one physical disk; determining whether to store the data in a data log as uncompressed or compressed data based on a determined size of resulting compressed data. When the method determines to store the data as compressed, compressing the data and storing the compressed data in at least one sector in the data log. Otherwise, the method stores the data, uncompressed, in a plurality of sectors in the data log. The method generates a one or more state bits indicating (i) whether the data is stored as uncompressed or compressed, and (ii) if the data is stored as compressed, a size of the compressed data. The method then stores the one or more state bits in an entry of a logical map table associated with an LBA that corresponds to the data block.

A storage device that maps logical addresses to physical addresses includes a memory that stores machine instructions and a processor coupled to the memory that executes the machine instructions to store a compressed mapping table in the memory. The compressed mapping table correlates logical addresses to locations in a storage. The storage device also stores a bundle of uncompressed mapping table entries starting at a first location in a cache and maps a first logical address associated with the uncompressed mapping table entry to the first location.

Inventive aspects include a key value store engine including non-volatile memory configured to store key-value inode descriptors each including a key and an associated value. The key value store engine can include a volatile memory to store a key hash tree and a collision hash tree. The key hash tree can include nodes each having a hash of one of the keys. The collision hash tree can include nodes each having a collided hash associated with two or more different keys. Each of the nodes of the key hash tree can include a collision flag indicating whether two or more different hashes correspond to a collided hash. The volatile memory can store a collision linked list including linked list nodes each having a key-value inode number indicating a location of a corresponding key-value inode descriptor stored in the non-volatile memory. The key value store engine can include a key value logic section.

A cache log module stores an ordered log of cache storage operations sequentially within the physical address space of a non-volatile storage device. The log may be divided into segments, each comprising a set of log entries. Data admitted into the cache may be associated with respective log segments. Cache data may be associated with the log segment that corresponds to the cache storage operation in which the cache data was written into the cache. The backing store of the data may be synchronized to a particular log segment by identifying the cache data pertaining to the segment (using the associations), and writing the identified data to the backing store. Data lost from the cache may be recovered from the log by, inter alia, committing entries in the log after the last synchronization time of the backing store.

Managing connected data, such as a graph data store, includes a computing device with persistent memory and volatile memory. The computing device stores a graph data store with a plurality of nodes and edges in persistent memory. Each of the edges defines the relationship between at least two of the nodes. The nodes and edges may contain tags and properties containing additional information. In response to a search request query, the computing device generates an iterator object stored in volatile memory with a reference to one or more nodes and/or edges in the graph data store. The split between volatile and persistent memory allocation could be used for other objects, such as allocators and transactions. Other embodiments are described and claimed.