A variety of applications can include systems and/or methods of partial save of memory in an apparatus such as a non-volatile dual in-line memory module. In various embodiments, a set of control registers of a non-volatile dual in-line memory module can be configured to contain an identification of a portion of dynamic random-access memory of the non-volatile dual in-line memory module from which to back up content to non-volatile memory of the non-volatile dual in-line memory module. Registers of the set of control registers may also be allotted to contain an amount of content to transfer from the dynamic random-access memory content to the non-volatile memory. Additional apparatus, systems, and methods are disclosed.

A computer storage device having a host interface, a controller, non-volatile storage media, and firmware. The firmware instructs the controller to: limit a crypto key to be used in data access requests made in a first namespace allocated on the non-volatile storage media of the computer storage device; store data in the first namespace in an encrypted form that is to be decrypted using the crypto key; free a portion of the non-volatile storage media from the first namespace, the portion storing the data; and make the portion of the non-volatile storage media available in a second namespace without erasing the data stored in the portion of the non-volatile storage media.

Techniques for computer memory management are disclosed herein. In one embodiment, a method includes in response to receiving a request for allocation of memory, determining whether the request is for allocation from a first memory region or a second memory region of the physical memory. The first memory region has first memory subregions of a first size and the second memory region having second memory subregions of a second size larger than the first size of the first memory region. The method further includes in response to determining that the request for allocation of memory is for allocation from the first or second memory region, allocating a portion of the first or second multiple memory subregions of the first or second memory region, respectively, in response to the request.

According to one embodiment, a memory system includes a non-volatile semiconductor memory, a block management unit, and a transcription unit. The semiconductor memory includes a plurality of blocks to which data can be written in both the first mode and the second mode. The block management unit manages a block that stores therein no valid data as a free block. When the number of free blocks managed by the block management unit is smaller than or equal to a predetermined threshold value, the transcription unit selects one or more used blocks that stores therein valid data as transcription source blocks and transcribes valid data stored in the transcription source blocks to free blocks in the second mode.

Various embodiments set forth techniques for free space management in a block store. The techniques include receiving a request to allocate one or more blocks in a block store, accessing a sparse hierarchical data structure to identify an allocator page identifying a region of a backing store having a greatest number of free blocks, and allocating the one or more blocks.

The invention relates to a method, a non-transitory computer program product, and an apparatus for managing data storage. The method performed by a flash controller includes: obtaining information indicating a subregion to be activated, where the subregion is associated with a logical block address (LBA) range; triggering a garbage collection (GC) process being performed in background to migrate user data of all the or a portion of the LBA range associated with the subregion to continuous physical addresses in a flash device; and updating content of a plurality of entries associated with the subregion according to migration results, where each entry includes information indicating which physical address that user data of a corresponding logical address is physically stored in the flash device.

Cache-based trace logging using tags in an upper cache level. A processor influxes a cache line into a first cache level from an upper second cache level. Influxing the cache line into the first cache level includes, based on the first cache level being a recording cache, the processor reading a tag that is (i) stored in the second cache level and (ii) associated with the cache line. Based on reading the tag, the processor determines whether a first value of the cache line within the second cache level has been previously captured by a trace. The processor performs one of (i) when the first value is determined to have been previously logged, following a logged value logic path when influxing the cache line; or (ii) when the first value is determined to have not been previously logged, following a non-logged value logic path when influxing the cache line.

Methods, systems, and devices for cache block budgeting techniques are described. In some memory systems, a controller may configure a memory device with a cache. The cache may include a first subset of blocks configured to statically operate in a first mode and a second subset of blocks configured to dynamically switch between operating in the first mode and a second mode. A block operating in the second mode may be configured to store relatively more bits per memory cell than a block operating in the first mode. The controller may track and store, for each block of the second subset of blocks, a respective ratio of cycles performed in the first mode to cycles performed in the second mode. The controller may select a block from the second subset of blocks to switch between modes responsive to a trigger and based on the respective ratio for the block.

Techniques for using erasure coding in a single region to reduce the likelihood of losing objects in a cloud object storage platform are provided. In one set of embodiments, a computer system can upload a plurality of data objects to a region of a cloud object storage platform, where the plurality of data objects including modifications to a data set. The computer system can further compute a parity object based on the plurality of data objects, where the parity object encodes parity information for the plurality of data objects. The computer system can then upload the parity object to the same region where the plurality of data objects was uploaded.

Systems and methods are described for enabling garbage collection on data storage systems. Traditional garbage collection often attempts to track use of data items on an individual level, deleting each item when it is no longer used. In distributed systems, tracking use on an individual level is difficult, and may require centralized knowledge across the system with respect to individual data items. Provided herein is a “coarse-grained” garbage collection mechanism, which divides objects into logical groups referred to as “roots.” Each root has a life cycle. While active, new data can be stored in a root. While inactive, use of data within a root can cause that date to be copied to a different, active root. When the system detects that data hasn't been used in an inactive root for a threshold period, the root can be considered “dead” and data within the root may be deleted.