An illustrative method includes receiving a write request to write payload data to a virtual storage volume; transmitting the write request to a plurality of storage nodes each storing a replica of the virtual storage volume; acknowledging the write request only after a quorum of the storage nodes has stored the payload in their respective kernel memory; and flushing the payloads stored in each kernel memory to persistent storage only after a threshold number of outstanding write requests that have been acknowledged, but not yet flushed, has been reached, the flushing configured to optimize performance for synchronous workloads.

An illustrative method includes receiving a write request to write payload data to a virtual storage volume; transmitting the write request to a plurality of storage nodes each storing a replica of the virtual storage volume; acknowledging the write request only after a quorum of the storage nodes has stored the payload in their respective kernel memory; and flushing the payloads stored in each kernel memory to persistent storage only after a threshold number of outstanding write requests that have been acknowledged, but not yet flushed, has been reached, the flushing configured to optimize performance for synchronous workloads.

A data access system including a processor and a storage system including a main memory and a cache module. The cache module includes a FLC controller and a cache. The cache is configured as a FLC to be accessed prior to accessing the main memory. The processor is coupled to levels of cache separate from the FLC. The processor generates, in response to data required by the processor not being in the levels of cache, a physical address corresponding to a physical location in the storage system. The FLC controller generates a virtual address based on the physical address. The virtual address corresponds to a physical location within the FLC or the main memory. The cache module causes, in response to the virtual address not corresponding to the physical location within the FLC, the data required by the processor to be retrieved from the main memory.

A data access system including a processor and a storage system including a main memory and a cache module. The cache module includes a FLC controller and a cache. The cache is configured as a FLC to be accessed prior to accessing the main memory. The processor is coupled to levels of cache separate from the FLC. The processor generates, in response to data required by the processor not being in the levels of cache, a physical address corresponding to a physical location in the storage system. The FLC controller generates a virtual address based on the physical address. The virtual address corresponds to a physical location within the FLC or the main memory. The cache module causes, in response to the virtual address not corresponding to the physical location within the FLC, the data required by the processor to be retrieved from the main memory.

Volume migration among a set of storage systems synchronously replicating a dataset for a volume, where volume migration includes: initiating a transfer of the volume in dependence upon determining that a performance metric for accessing the volume stored on a first storage system would improve if transferred to a second storage system; and during the transfer of the volume: determining status information for the transfer; intercepting an I/O operation directed to the volume; and directing, in dependence upon the status information, the I/O operation to either the first storage system or the second storage system.

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 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.

This disclosure relates to a method for situation-dependent storage of data of a system, in which data of the system is detected, is amalgamated in at least one data block and is stored in a volatile memory, and in which, in response to the occurrence of at least one predefined trigger event in the at least one data block, amalgamated data are transferred from the volatile memory into a read-only memory, and in which a time window, in which the data for the at least one data block is captured, is selected automatically and dynamically according to the at least one trigger event.

This disclosure relates to a method for situation-dependent storage of data of a system, in which data of the system is detected, is amalgamated in at least one data block and is stored in a volatile memory, and in which, in response to the occurrence of at least one predefined trigger event in the at least one data block, amalgamated data are transferred from the volatile memory into a read-only memory, and in which a time window, in which the data for the at least one data block is captured, is selected automatically and dynamically according to the at least one trigger event.

In one aspect of write sort management in accordance with the present disclosure, a sort/no-sort determination is made prior to issuing to a write command to a target storage controller. The write command identifies a write data unit such track write data, for example, of a first write list of write data units to be written to storage locations of storage. The write command further identifies the storage location at which the write data unit of the first write list is to be stored. In one embodiment, the sort/no-sort determination determines whether an insertion point for an entry in a target write list is to be determined as a function of a write list search such as a logarithmic time search for a write list sort. As a result, the write list search for a write list sort, may be selectively either performed or bypassed for insertion of the target write list entry as a function of the sort/no-sort determination Other aspects and advantages are provided, depending upon the particular application.