105 results about "Flash file system" patented technology

Reclamation of an Erase Unit of a flash memory is performed concurrently with a file operation on the flash memory by initiating a reclamation operation on the individually erasable portion of the memory, by suspending the reclamation operation for the file operation, by performing the file operation, and by resuming the reclamation operation.

System and method for performing operations in a multi-class file system without requiring split mirrors. For one or more storage classes in the multi-class file system, operations that require stable copies of the storage classes may be performed without using split mirrors. In one embodiment, read-only data may be assigned and / or migrated to lower storage classes, and operations may be performed on the read-only storage classes without using split mirrors. In one embodiment, to perform an operation without using a split mirror, a write lock of a storage class may be examined to determine if the write-locked storage class has been written to during the operation on the storage class and, if so, the operation may be retried for the storage class. In one embodiment, the file system software may be blocked from enabling a storage class for writing for the duration of the operation on the storage class.

A virtual file system and method. The system architecture enables a plurality of underlying file systems running on various file servers to be “virtualized” into one or more “virtual volumes” that appear as a local file system to clients that access the virtual volumes. The system also enables the storage spaces of the underlying file systems to be aggregated into a single virtual storage space, which can be dynamically scaled by adding or removing file servers without taking any of the file systems offline and in a manner transparent to the clients. This functionality is enabled through a software “virtualization” filter on the client that intercepts file system requests and a virtual file system driver on each file server. The system also provides for load balancing file accesses by distributing files across the various file servers in the system, through migration of data files between servers.

A content management system and method are disclosed having one or more shared file systems located on one or more networks having a firewall. The content management system includes an explorer client, a mounting client, and a gateway. The gateway is in communication with both the explorer client and the mounting client. The explorer client forms a profile of a user device by determining the characteristics of the user device. The mounting client determines the capabilities of the one or more file systems and where content resides on each of the one or more file systems. The gateway then creates a virtual abstraction layer based on the profile of the user device and the capabilities of the one or more file systems.

This invention discloses a flash file system management method, which comprises the following steps: to divide the flash memory into FAT area and data memory area; to establish the space mapping form and to write the data block of each file into the block; to write the new file ID, block number, file researching number into the record; then to orderly write each data block into the spare block and to write each data block number into relative positions of the space mapping form; only to operate the file data memory area when updating file data; to identify the place of the data to be read when reading the data for searching the data block.

A shared file system may be updated by a non-native operating system writing information to a change file, while a native operating system is in a suspend or hibernation mode; after writing, the non-native operating system is placed in a suspend or hibernation mode and the native system activates and then retrieves the updated information from the change file and writes the updated information to a shared file system. The native operating system returns to a suspend or hibernate state before the non-native operating resumes operation. The updated information may be written as provided by the non-native operating system, or further updated by the native operating system before being written to the shared file system. The change file is created by the native operating system, and may be a reserved portion of the shared file system or may be a separate portion of non-volatile memory. The native and non-native operating systems operate both concurrently and independent of one another; thereby, preventing conflicts during file system updating.

A shared storage distributed file system is presented that provides applications with transparent access to a storage area network (SAN) attached storage device. This is accomplished by providing clients read access to the devices over the SAN and by requiring most write activity to be serialized through a network attached storage (NAS) server. Both the clients and the NAS server are connected to the SAN-attached device over the SAN. Direct read access to the SAN attached device is provided through a local file system on the client. Write access is provided through a remote file system on the client that utilizes the NAS server. A supplemental read path is provided through the NAS server for those circumstances where the local file system is unable to provide valid data reads.Consistency is maintained by comparing modification times in the local and remote file systems. Since writes occur over the remote file systems, the consistency mechanism is capable of flushing data caches in the remote file system, and invalidating metadata and real-data caches in the local file system. It is possible to utilize unmodified local and remote file systems in the present invention, by layering over the local and remote file systems a new file system. This new file system need only be installed at each client, allowing the NAS server file systems to operate unmodified. Alternatively, the new file system can be combined with the local file system.

Disclosed herein are a flash file system and an address translation method. The flash file system includes a file system, a Flash Translation Layer (FTL), and flash memory. The FTL receives Local Block Addresses (LBAs) from the file system, and translates the LBAs into Physical Block Address (PBAs. The flash memory receives the resulting PBAs. The FTL includes a memory block in which a multi-stage clustered hash table for mapping the LBAs to the PBAs is stored, and performs the address translation using the clustered hash table.

A mirror file systems (MFS) is a virtual file system that links two or more file systems together and mirrors between them in real time. The file systems linked and mirrored through the mirror file system can be a local file system connected to a physical device, or a network file system exported by a remote system on a network. The mirroring mechanism is established by linking a file system to another file system on a single directory through an MFS mounting protocol. User applications perform normal file system operation and file / directory operation system calls like open, read, write and close functions from the pathname of either file system. When updates occur, such as a write operation, the MFS mechanism ensures that all data updates go to both the file systems in real time.

Implicit journaling of a file operation relating to a file stored in a flash memory is performed by locking a semaphore corresponding to the file on which a file operation is to be performed, by initializing journaling of the file operation using the file map, by performing the file operation on the file, by completing journaling of the file operation using a file map corresponding to the file, and unlocking the semaphore. Additionally or alternatively, a file system is placed in a stable state following an interruption occurring during a file operation by scanning File Maps corresponding to the files, determining whether a file operation is incomplete based on validity flags contained in the file maps, and performing remediation so as to eliminate the incomplete file operation.

Reclamation of an Erase Unit of a flash memory is performed concurrently with a file operation on the flash memory by initiating a reclamation operation on the individually erasable portion of the memory, by suspending the reclamation operation for the file operation, by performing the file operation, and by resuming the reclamation operation.

A device driver including a flash memory file system and method thereof and a flash memory device and method thereof are provided. The example device driver may include a flash memory file system configured to receive data scheduled to be written into the flash memory device, the flash memory file system selecting one of a first data storage area and a second data storage area within the flash memory device to write the received data to based upon an expected frequency of updating for the received data, the first data storage area configured to store data which is expected to be updated more often than the second data storage area. The example flash memory device may include a first data storage area configured to store first data, the first data having a first expected frequency for updating and a second data storage area configured to store second data, the second data having a second expected frequency of updating, the first expected frequency being higher than the second expected frequency.

Disclosed herein are a flash file system and an address translation method. The flash file system includes a file system, a Flash Translation Layer (FTL), and flash memory. The FTL receives Local Block Addresses (LBAs) from the file system, and translates the LBAs into Physical Block Address (PBAs. The flash memory receives the resulting PBAs. The FTL includes a memory block in which a multi-stage clustered hash table for mapping the LBAs to the PBAs is stored, and performs the address translation using the clustered hash table.

A flash memory management system for a memory for accessing data from a host, the system including physical units and virtual units of the memory and a mapping mechanism of each virtual unit into one or more physical units, wherein the number of binary bits required for accessing each of the virtual units is less than the number of binary bits required for accessing each of the physical units.

File system restoration is made more flexible through the use of indicators of individual file restoration status throughout the restoration process. Such indicators are particularly useful in the restoration of large file systems where, for example, the number of files may range upwards of several hundred million. Since file system restoration for large systems takes such a relatively long time, the present invention provides various degrees of individual file access even as the restoration process is being carried out. During file system restoration times, file access may be full or limited to a file's attributes. Most advantageously, the present invention is capable of providing full, dynamically driven (on-demand) file access even during file system restoration operations.

Systems and methods are disclosed that track a document within a file system using document identifier (DOCID) that is preserved during safe save operations. The DOCID can be a universally unique identifier (UUID). The DOCID can be generated on a local file system or generated during a synchronization process with a remote synchronization service. Applications can opt in to document tracking. The kernel of the operating system can monitor file system operations on a per-application and per-thread basis and determine when a processing thread is about to perform a safe save. When a sequence of file system operations indicates that a safe save is to be performed, the kernel can generate and store a tombstone record that includes the DOCID and other metadata of the tracked document and pass the DOCID and metadata to the newly saved document.

A read-write snapshot copy facility is constructed from a hierarchical storage management facility. The read-write snapshot copy file system initially comprises stub files pointing to the files in a read-only snapshot copy file system. When an application writes to a file in the read-write snapshot copy, the read-write snapshot copy facility migrates a copy of the file to replace the stub file, and then writes to the migrated file. Because the read-write snapshot copy facility references the files in the read-only snapshot file system in a network namespace using standard protocols such as NFS or CIFS, the read-write snapshot copy facility permits referencing of distributed read-only snapshot file systems in an open (heterogeneous) network environment, and the read-write snapshot copy is scalable by linking the read-write snapshot copy facility to multiple file servers containing read-only snapshot file systems.

A method for initializing and operating a flash memory file system and a computer-readable medium storing a program adapted to perform the method are disclosed. The method includes programming the flash memory file system in order to conceptually divide logical blocks into logical groups, and storing erasure data for one of the logical groups in a first region of a meta block. The method also includes loading erasure data for one logical group into an external memory device and mapping the logical blocks of the current logical group to the physical blocks in accordance with the erasure data loaded into the external memory device. The method also includes storing data of a data file in a data block of a flash memory device in accordance with the mapping of the logical blocks to the physical blocks.

A method for synchronizing a local file system (LFS) and a remote (cloud) file system (RFS) includes the step of storing events indicative of differences between the LFS and the RFS, where the events are associated with file system objects of the LFS and RFS. The method further includes the steps of prioritizing the events, generating file system operations for the events based at least in part on the prioritization of the events, and performing at least some of the file system operations to synchronize the LFS and RFS. Prioritizing the events includes defining a plurality of service classes (e.g., based on type of event, event attribute, etc.), assigning a priority to each of the service classes, and assigning each event to one of said service classes. Systems are also described. The invention allocates limited synchronization resources based on a predefined policy to synchronize important file system objects sooner.

As file systems reach the petabytes scale, users and administrators are increasingly interested in acquiring high-level analytical information for file management and analysis. Two particularly important tasks are the processing of aggregate and top-k queries which, unfortunately, cannot be quickly answered by hierarchical file systems such as ext3 and NTFS. Existing pre-processing based solutions, e.g., file system crawling and index building, consume a significant amount of time and space (for generating and maintaining the indexes) which in many cases cannot be justified by the infrequent usage of such solutions. User interests can often be sufficiently satisfied by approximate (i.e., statistically accurate) answers. A just-in-time sampling-based system can, after consuming a small number of disk accesses, produce extremely accurate answers for a broad class of aggregate and top-k queries over a file system without the requirement of any prior knowledge. The system is efficient, accurate and scalable.

The flash file system includes a flash memory and a subsystem interfacing between the flash memory and a host system. The subsystem includes a hierarchical structure of a host system interface, cache memory system, flash translation layer unit and a flash memory interface. The host system interface interfaces with the host system. The cache memory system has a storage capacity of a predetermined number of data units and stores data for transfer to and from the host system via the host system interface. The flash translation layer unit maps a logical address received from the host system via the host system interface and the cache memory into a physical address of the flash memory. The flash memory interface interfaces with the flash memory to transfer data to the flash memory from the cache memory system based on the physical address received from the flash translation layer unit and to transfer data from the flash memory to the cache memory system based on the physical address received from the flash translation layer unit.

A method, apparatus and computer product wherein means and mechanisms are provided whereby, in a distributed or clustered shared file system, (1) concurrency classes may be defined specifying granularity of locking, whether locks are cached, and whether modified data is written-through at the completion of updates, (2) certain files, file types, or files and / or file types as used by given applications or classes of applications, may be associated with concurrency classes, and (3) for each usage of a file by an application, the associated concurrency class determines a policy for choosing specific concurrency and coherency control mechanisms to be used for accessing the given file.

The invention discloses a file access method of a Linux virtual machine disk under a Windows platform, which comprises a mount program for the Linux virtual machine disk and a drive program for an ext2 / ext3 file system analysis. The file access method is characterized in that the mount program uses a VMware Mount Utility tool provided by the VMware company, creates a virtual volume by using a VMDK (Virtual Machine Disk Format) file in a host operating system and provides a new logic disk letter for a user; the realized ext2 / ext3 file system analysis creates a device object to an I / O manager of a Windows kernel and registers the file system so that the Windows operating system can access file systems besides FAT, NTFS, CDFS and UDF; and the drive program is installed in the catalog of \Windows\system32\drivers and is used by the Windows host (including but not limited to) operating system to analyze a file system in ext2 / ext3 format.

The invention discloses a distributed block device driving method and system for cloud storage. The method comprises the steps that an I / O request transmitted from an upper-layer file system is converted into an access message of a virtual block device, a network card drive is called to send a data packet to a server, and therefore a true physical storage device on the server can be accessed. According to the distributed block device driving method and system, remote loading and running of various operating systems and instruction interfaces of various storage devices can be supported, and data requesting and processing can be efficiently finished.

A shared file system may be updated by a non-native operating system writing information to a change file, while a native operating system is in a suspend or hibernation mode; after writing, the non-native operating system is placed in a suspend or hibernation mode and the native system activates and then retrieves the updated information from the change file and writes the updated information to a shared file system. The native operating system returns to a suspend or hibernate state before the non-native operating resumes operation. The updated information may be written as provided by the non-native operating system, or further updated by the native operating system before being written to the shared file system. The change file is created by the native operating system, and may be a reserved portion of the shared file system or may be a separate portion of non-volatile memory. The native and non-native operating systems operate both concurrently and independent of one another; thereby, preventing conflicts during file system updating.

A method for synchronizing a local file system (LFS) and a remote (cloud) file system (RFS) includes the step of storing events indicative of differences between the LFS and the RFS, where the events are associated with file system objects of the LFS and RFS. The method further includes the steps of prioritizing the events, generating file system operations for the events based at least in part on the prioritization of the events, and performing at least some of the file system operations to synchronize the LFS and RFS. Prioritizing the events includes defining a plurality of service classes (e.g., based on type of event, event attribute, etc.), assigning a priority to each of the service classes, and assigning each event to one of said service classes. Systems are also described. The invention allocates limited synchronization resources based on a predefined policy to synchronize important file system objects sooner.

The invention discloses a realizing method of an embedded Linux large capacity flash file system. The method comprises sectionalized storage, data page distribution, refuse collection, logic structure zoning, file system initialization, directory searching, file displacement location, data reading and data writing. The method realizes the embedded Linux large capacity Nand flash file system and is beneficial for the management of embedded Linux large capacity Nand flash. The realized large capacity Nand flash file system can be applied to the large capacity Nand flash management and is beneficial to the utilization of embedded storing.

Internally, a production file system and each of its related snapshot file systems have a common file system identifier (fid′) and a unique respective file system identifier (fsid′). Externally, the production file system and each of its related snapshot file systems has a common file system identifier (fsid) and a unique respective file identifier (fid). For example, the “fsid” and “fid” for the production and snapshot file systems are interchanged between a client-server protocol layer and a logical volume layer in a file server. Moreover, the file handle for an object indicates whether an object is in either a production file system that is not configured to have related snapshots, a production file system that is configured to have related snapshots, or a snapshot file system. When the object is in a snapshot file system, the file handle also indicates the related production file system.

Disclosed herein are a data update apparatus and method. The apparatus includes an update identification unit, a data storage unit, a block allocation unit, and a data update unit. The update identification unit determines whether the input / output request signal corresponds to an update signal. The data storage unit stores mapping information about the blocks of an arbitrary file in a metadata area. The block allocation unit stores addresses of one or more free blocks, which are selected from among blocks included in the data storage unit and in which data has not been stored. The data update unit acquires the addresses of the free blocks, writes the update data to the free blocks, and updates existing block addresses, which belong to information included in mapping information of the data storage unit and to which the update data has been mapped, with the addresses of the free blocks.

One aspect of the present invention provides an operation for recovering lost space and maintaining data consistency in a storage environment by providing a two-way orphan reconciliation method for extremely large file systems, such as a Hierarchical Storage Management (HSM) system which manages billions of files. This highly scalable and parallelizable orphan identification process may be used in a HSM controlled environment to enable the execution of a two-way file orphan check. In one embodiment, this orphan check identifies file system client orphans and server object orphans in a single pass by comparing a queue containing a list of migrated files on a storage repository server with a queue containing a list of stub files on a file system. If the queue elements do not match, a file system orphan or server object orphan can appropriately be identified.