There is provided a method for managing a solid state storage system with hybrid storage technologies. The method includes monitoring one or more storage request streams to identify operating mode characteristics therein from among a set of possible operating mode characteristics. The set of possible operating mode characteristics correspond to a set of available operating modes of the hybrid storage technologies. The method further includes identifying a current operating mode from among the set of available operating modes responsive to the identified operating mode characteristics. The method also includes predicting a likely future operating mode responsive to variations in workload requirements to generate at least one future operating mode prediction. The method additionally includes controlling at least one of data placement, wear leveling, and garbage collection, responsive to the at least one future operating mode prediction.

A vehicle memory sub-system can be switched from a normal mode to a pre-shutdown mode and initiate a media management operation before shutting down. The mode switch and/or media management operation can be performed in response to receiving a shutdown or pre-shutdown command for the vehicle. After completion of the memory management operation the vehicle and/or memory sub-system can be shutdown.

A memory controller, a memory system and a method of operating a memory controller controlling a memory device are described. The memory controller may include a workload manager in communication with the memory device in which data is written and is read, the workload manager configured to acquire an amount of write data written to the memory device during a preset reference time, calculate a workload parameter indicating a ratio of the amount of write data to a reference write amount, and store the workload parameter for the preset reference time, and a performance manager configured to control, based on the workload parameter, a certain background operation performed by the memory device during a period corresponding to the workload parameter.

Methods, systems, and devices for refresh counters in a memory system are described. In some examples, a memory device may include two or more counters configured to increment a respective count based on refresh operations performed on a memory array. A comparison may be made between two or more of the respective counts, which may include determining a difference between the respective counts or a difference in rate of incrementing. A memory device may transmit an indication to a host device based on determining a difference between counters, and the memory device, the host device, or both, may perform various operations or enter various operational modes based on the determined difference.

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.

Techniques manage a redundant array of independent disks. In such a technique, a response time of a first storage device in the RAID is compared to a first threshold. In response to the response time of the first storage device exceeding the first threshold, the first storage device is configured as a pseudo-degraded storage device, such that the pseudo-degraded storage device is responsive to write requests only.

A system including a stack of two or more layers of volatile memory, such as layers of a 3D stacked DRAM memory, places data in the stack based on a temperature or a refresh rate. When a threshold is exceeded, data are moved from a first region to a second region in the stack, the second region having one or both of a second temperature lower than a first temperature of the first region or a second refresh rate lower than a first refresh rate of the first region.

Techniques involve determining the number of disks in a Redundant Array of Independent Disks (RAID) storage system, and the storage system comprises multiple types of mixed disks. The techniques further involve determining a target number of RAID sets to be allocated in the storage system according to the number of disks and a predetermined threshold, and then allocating the multiple types of disks to the RAID sets according to the target number and types of disks. Such techniques propose a way to allocate mixed disks to the corresponding RAID sets. When the RAID set grouping is performed to mixed disks of the storage system, the same type of disks are allocated in the same RAID set as much as possible, thereby improving the performance of the storage system.

In a storage system such as a SAN, NAS, or storage array that implements hierarchical performance tiers based rated drive access latency, on-drive compression is used on data stored on a first tier and off-drive compression is used on data stored on a second tier. Off-drive compression is more processor intensive and may introduce some data access latency but reduces storage requirements. On-drive compression is performed at or near line speed but generally yields lower size reduction ratios than off-drive compression. On-drive compression may be implemented at a higher performance tier whereas off-drive compression may be implemented at a lower performance tier. Further, space saving realized from on-drive compression may be applied to over-provisioning.

Responsive to a power-on of a memory device, an elapsed power-off time is identified based on a difference between a time at which the power-on occurred and a time at which a previous power-off of the memory device occurred. Responsive to a determination that the elapsed power-off time satisfies the elapsed time threshold criterion, a request to perform a first write operation on a memory unit of the memory device since power on is received, a performance parameter associated with the memory unit of the memory device is changed to a first parameter value that corresponds to a reduced performance level, and the write operation is performed on the memory unit of the memory device in accordance with the first parameter value that corresponds to the reduced performance level. Responsive to completion of the write operation, the performance parameter is changed to a value that corresponds to a normal performance level.