Systems for accessing client data is described. A request to access a first data block is received. The request indicates a first logical address referencing the first data block. First mapping data is employed to identify a first physical addresses corresponding to the first logical addresses. The first mapping data encodes a first LOM transaction ID and candidate local addresses. The first mapping data is employed to identify the candidate local address and the first LOM transaction ID. A usage table is employed to determine the current status of the first LOM transaction ID. The candidate local address is employed to access the first data block. Second mapping data is employed to identify an updated local address of the set of local addresses. The updated local address currently references the first data block. The updated local address is employed to access the first data block.

The present invention provides a method for accessing a secure digital (SD) card, which includes a voltage supply pin for receiving voltage supply from a host, at least one ground pin, a clock pin for receiving a clock signal from a host, a command pin for receiving a command from a host, and four data pins for writing data into the SD card or reading data from the SD card. The method includes receiving, via the command pin, an address extension command including a first address from a host, receiving, via the command pin, an access command including a second address from a host, and accessing, via the data pins, at least a memory location of the SD card indicated by a third address, which is a combination of the first address and the second address. The access command indicates an access operation to be performed on the SD card selected from: a single read operation, a single write operation, a multiple read operation, a multiple write operation and an erase operation.

An enhanced dynamic address translation facility product is created such that, in one embodiment, a virtual address to be translated and an initial origin address of a translation table of the hierarchy of translation tables are obtained. Dynamic address translation of the virtual address proceeds. In response to a translation interruption having occurred during dynamic address translation, bits are stored in a translation exception qualifier (TXQ) field to indicate that the exception was either a host DAT exception having occurred while running a host program or a host DAT exception having occurred while running a guest program. The TXQ is further capable of indicating that the exception was associated with a host virtual address derived from a guest page frame real address or a guest segment frame absolute address. The TXQ is further capable of indicating that a larger or smaller host frame size is preferred to back a guest frame.

A system and method for efficient and secure memory allocation in virtualized systems. A hypervisor receives, from a first virtual machine (VM), a message specifying a page of memory accessible to the first VM. The hypervisor determines that the page is not accessible to other VMs, adds an identifier identifying the page to a set of free page identifiers, and associates the identifier with the first VM. The hypervisor receives a page allocation request from a second VM, and in response attempts to locate an identifier associated with the second VM in the set of free page identifiers. Responsive to a successful attempt, the hypervisor allocates to the second VM a first page of memory corresponding to the located identifier, without clearing the first page. Responsive to an unsuccessful attempt, the hypervisor clears a second page of memory and allocates the cleared second page to the second VM.

Methods, systems, and devices for managing single-level and multi-level programming operations are described. During a first duration, a first set of resources of a memory system may be configured for single-level operations and a second set of resources of a memory system may be configured to multi-level operations. Also, during the first duration, a first set of data may be received and written to a first virtual block that spans the first set of resources in accordance with a single-level programming operation. Additionally, during the first duration, a second set of data may be transferred from the first set of resources or the second set of resources to a second virtual block that spans the second set of resources in accordance with a multi-level programming operation.

Embodiments of the present disclosure relate to method and apparatus for scaling out storage devices, and scaled-out storage devices by establishing a cross-device link between a first storage device and a second storage device; exchanging configuration information of at least one of the first storage device and the second storage via the cross-device link; creating, in the first storage device, a shadow object corresponding to a real object in the second storage device; and creating, in the second storage device, a shadow object corresponding to a real object in the first storage device; wherein each shadow object can expose feature and/or state of a corresponding real object to users without implementing a functioning logic of the corresponding real object.

Example methods are provided to perform disk assignment for multiple distributed computing clusters in a virtualized computing environment. The method may include determining whether disk assignment is required for a host to support a first virtualized computing instance from a first distributed computing cluster and a second virtualized computing instance from a second distributed computing cluster. The method may also include migrating first data placed on one or more second disks to one or more first disks, reassigning the one or more second disks from the first virtualized computing instance to the second virtualized computing instance, and placing second data on the one or more second disks. The first data may be for access by the first virtualized computing instance to execute a first distributed computing application, and the second data may be for access by the second virtualized computing instance to execute a second distributed computing application.

A computer-implemented method for synthesizing virtual hard drives may include (1) identifying a data object as an underlying source for synthesizing a virtual hard drive to store data within the data object, (2) generating hard drive metadata for the synthetic virtual hard drive, (3) synthesizing the virtual hard drive as a representation of a virtual hard drive by associating the generated hard drive metadata with the data object as the underlying source such that a data management system is configured to: (a) direct requests for hard drive metadata of the synthetic virtual hard drive to the generated hard drive metadata, and (b) direct requests for hard drive content of the synthetic virtual hard drive to the data object as the underlying source for the synthetic virtual hard drive. Various other methods, systems, and computer-readable media are also disclosed.

A processing device in a host computer system receives an instruction to write data to a storage device coupled to the host computer system and store a copy of the data in a cache of the host computer system. The processing device initiates a write operation to write the data from the cache to the storage device and detects that the storage device is disconnected from the host computer system during execution of the write operation. In response to detecting that the storage device is disconnected, the processing device may suspend execution of at least one of a virtual machine or a process that issued the first instruction. After determining that the storage device is reconnected to the host computer system, the processing device can resumes the write operation to continue writing the data from the cache to the storage device. The processing device may further cache read data requested from the storage device so that the virtual machine can continue to access the read data from the cache in the event that the storage device is disconnected.

The deterioration of the operational efficiency of an optimal object placement device caused by the degradation in the access speed to the objects is inhibited. An optimal object placement device optimizes, in an information processing system having a storage area in each of a plurality of sites and in which a user can access objects stored in the storage area of all of the sites from each of the sites, placement of each of the objects; and an optimal object placement method is executed by the optimal object placement device, wherein control is executed for detecting an access tendency of the user's access to the objects.