Systems, methods, and computer program products for mirroring dual writeable storage arrays are provided. Various embodiments provide configurations including two or more mirrored storage arrays that are each capable of being written to by different hosts. When commands to write data to corresponding mirrored data blocks within the respective storage arrays are received from different hosts at substantially the same time, write priority for writing data to the mirrored data blocks is given to one of the storage arrays based on a predetermined criterion or multiple predetermined criteria.

Methods and apparatus for enhancing operating system integrity using non-volatile system memory are described. A computer system includes a system memory coupled to one or more processors. The system memory comprises at least a non-volatile portion. Memory is allocated from the non-volatile portion to store selected metadata associated with an operating system component that supports input-output (I/O) operations. In response to an operation that results in a metadata change at the component, a metadata entry is stored in the non-volatile portion. Subsequent to a failure event, contents of the metadata entry are read from the non-volatile portion to restore a state of the component.

Methods and apparatus for enhancing logging using non-volatile system memory are described. A computer system includes a system memory coupled to one or more processors. The system memory comprises at least a non-volatile portion. A range of memory locations within the non-volatile portion is selected as a low-latency high-durability log staging area. A plurality of log records representing respective events detected by one or more executable programs are generated, and at least a subset of the records is stored in the log persistence area. For analysis subsequent to a failure that results in a loss of data stored in a volatile portion of the system memory, log records written to the staging area within a time window immediately prior to the failure event are provided.

Disclosed herein is an information processing device including a host unit adapted to request data access by specifying a logical address of a secondary storage device, and a controller adapted to accept the data access request and convert the logical address into a physical address using an address conversion table to perform data access to an associated area of the secondary storage device, in which an address space defined by the address conversion table includes a coarsely granular address space that collectively associates, with logical addresses, physical addresses that are in units larger than those in which data is read.

A management method of cache files in storage space, adapted to a storage space storing a plurality of cache files, the management method comprises: forming a cache file status list which records a plurality of file names and a plurality of file status; determining whether a storage condition of the storage space is in a healthy condition; assigning a plurality of corresponding tags to the plurality of file status when the storage condition is not in the healthy condition, and forming a sorted cache file list; and deleting the last file name from the sorted cache file list and the cache file from the storage space corresponding to the file name, wherein the sorted cache file list records the file names which are sorted from a file name of a cache file that should be kept most to another file name of another cache file that should be deleted most.

A cache space management method and apparatus are disclosed. In the method, first, a hit rate of the read cache of the storage system is obtained; and then, a size of the read cache and a size of the metadata cache are adjusted based on the hit rate of the read cache. In the foregoing technical solution, the size of the read cache and the size of the metadata cache are dynamically adjusted by using the hit rate of the read cache as a decision factor. For example, when the hit rate of the read cache is relatively high, the size of the read cache may be increased.

The described technology is generally directed towards fault tolerant cluster data handling techniques, as well as devices and computer readable media configured to perform the disclosed fault tolerant cluster data handling techniques. Nodes in a computing cluster can be configured to generate wire format resources corresponding to operating system resources. A wire format resource can comprise a cache key and a hint information to locate data, such as a file, corresponding to the operating system resource. The wire format resource can be stored in a resource cache along with a pointer that points to the operating system resource. The wire format resource can also be provided to client devices. Nodes in the computing cluster can be configured to receive and process client instructions that include wire format resources, as well as to use hint information to re-allocate data associated with a wire format resource.

Example storage systems, file system interfaces, and methods provide cache commit timing management for aggregated writes. A system includes a data cache configured to aggregate data requests in buffer segments. A cache manager determines a delay threshold for each buffer based on usage values of the data cache. The cache manager monitors a commit time value, determines when the commit time value satisfies the delay threshold, and moves aggregate data elements from the buffer to persistent storage.

An apparatus includes a memory including a shared page cache and program instructions for a distributed virtual file system (VFS) for use in performing input/output (I/O) operations. An operating system of the computing system executes a central VFS in a first thread and executes a first application and the program instructions for the distributed VFS in a second thread. The distributed VFS determines that a first page, including data to which a first application has requested access, is stored in the shared page cache. In response to the determination, the distributed VFS accesses the requested data from the shared page cache without signaling the operating system or the central VFS. The computing system may be implemented in a device including a microkernel operating system.

A system and method for providing dynamic I/O virtualization is herein disclosed. According to one embodiment, a device capable of performing hypervisor-agnostic and device-agnostic I/O virtualization includes a host computer interface, memory, I/O devices (GPU, disk, NIC), and efficient communication mechanisms for virtual machines to communicate their intention to perform I/O operations on the device. According to one embodiment, the communication mechanism may use shared memory. According to some embodiments, the device may be implemented purely in hardware, in software, or using a combination of hardware and software. According to some embodiments, the device may share its memory with guest processes to perform optimizations including but not limited to a shared page cache and a shared heap.