Methods, systems, and devices for distributed caching of encrypted encryption keys are described. Some multi-tenant database systems may support encryption of data records. To efficiently handle multiple encryption keys across multiple application servers, the database system may store the encryption keys in a distributed cache accessible by each of the application servers. To securely cache the encryption keys, the database system may encrypt (e.g., wrap) each data encryption key (DEK) using a second encryption key (e.g., a key encryption key (KEK)). The database system may store the DEKs and KEKs in separate caches to further protect the encryption keys. For example, while the encrypted DEKs may be stored in the distributed cache, the KEKs may be stored locally on application servers. The database system may further support “bring your own key” (BYOK) functionality, where a user may upload a tenant secret or tenant-specific encryption key to the database.

A hybrid memory system provides rapid, persistent byte-addressable and block-addressable memory access to a host computer system by providing direct access to a both a volatile byte-addressable memory and a volatile block-addressable memory via the same parallel memory interface. The hybrid memory system also has at least a non-volatile block-addressable memory that allows the system to persist data even through a power-loss state. The hybrid memory system can copy and move data between any of the memories using local memory controllers to free up host system resources for other tasks.

A data storage system can employ a read destructive memory configured to fill a first cache with a first data set from a data repository prior to populating a second cache with a second data set describing the first data set with the first and second cache each having non-volatile ferroelectric memory cells. An entirety of the first cache may be read in response to a cache hit in the second cache with the cache hit responsive to a data read command from a host and with the first cache being read without a refresh operation restoring the data of the first cache.

A hybrid memory system provides rapid, persistent byte-addressable and block-addressable memory access to a host computer system by providing direct access to a both a volatile byte-addressable memory and a volatile block-addressable memory via the same parallel memory interface. The hybrid memory system also has at least a non-volatile block-addressable memory that allows the system to persist data even through a power-loss state. The hybrid memory system can copy and move data between any of the memories using local memory controllers to free up host system resources for other tasks.

Methods, systems, and devices for using page line filler data are described. In some examples, a memory system may store data within a write buffer of the memory system. The memory system may initiate an operation to transfer the write buffer data to a memory device, for example, due to a command to perform a memory management operation (e.g., cache synchronization, context switching, or the like) from a host system. In some examples, a quantity of write buffer data may fail to satisfy a data size threshold. Thus, the memory system may aggregate the data in the write buffer with valid data from a block of the memory device associated with garbage collection. The memory system may aggregate the write buffer data with the garbage collection data until the aggregated data satisfies the data size threshold. The memory system may then write the aggregated data to the memory device.

Staging data on a storage element integrating fast durable storage and bulk durable storage, including: receiving, at a storage element integrating fast durable storage and bulk durable storage, a data storage operation from a host computer; storing data corresponding to the data storage operation within fast durable storage in accordance with a first data resiliency technique; and responsive to detecting a condition for transferring data between fast durable storage and bulk durable storage, transferring the data from fast durable storage to bulk durable storage in accordance with a second data resiliency technique.

Apparatuses, systems, and methods for hierarchical memory systems are described. A hierarchical memory system can leverage persistent memory to store data that is generally stored in a non-persistent memory, thereby increasing an amount of storage space allocated to a computing system at a lower cost than approaches that rely solely on non-persistent memory. An example method includes receiving a request to access data via an input/output (I/O) device, determining whether the data is stored in a non-persistent memory device or a persistent memory device, and redirecting the request to access the data to logic circuitry in response to determining that the data is stored in the persistent memory device.

The role of a node component of a distributed application may be changed without the need to terminate a current OS process implementing the node component. A first component on a first node of a distributed file server may be designated as a control path master and configured to execute a first group of services defined for the control path master as part of a first OS process. One or more other components on one or more other nodes of the distributed file server may be designated as a control path agent and configured to execute a second group of services defined for the control path agent as part of a respective second OS process. The control path master may be changed to a control path agent, and a control path agent may be changed to a control path master, without having to reboot the control path component in question.

Methods and systems for a networked storage system are provided. One method includes transmitting, by a first node, an invalidation request to a second node to invalidate an entry of a storage location cache of the second node, the entry indicating a storage location to write data in response to a write request received by the first node; updating, by the first node, a memory structure at the first node for sending a heartbeat message to disable use of the storage location cache by the second node; and responding, by the first node, to the write request, after a response to disable the use of the storage location cache is received from the second node or a certain duration, T1, has elapsed since the heartbeat message was sent to the second node and no response was received from the second node.

Reversing deletion of a virtual machine including managing, by a storage system, a repository of virtual machine snapshots on a datastore; receiving, by the storage system, a request to recover a deleted virtual machine from the datastore; accessing, by the storage system, the repository of virtual machine snapshots on the datastore to generate a list of deleted virtual machines associated with virtual machine snapshots in the repository of virtual machine snapshots; receiving, by the storage system, a selection of one of the deleted virtual machines in the list of deleted virtual machines; and recovering, by the storage system, the selected deleted virtual machine using a virtual machine snapshot for the selected deleted virtual machine.