摘要:
A method and mechanism for managing a time-indexed block map in a file system configured to store multiple versions of file data. A file system includes inodes or other structures corresponding to files in the system. Responsive to creating a file, one or more blocks are allocated for use in storing the file data. A block map is maintained for the file and is updated to include an identification of the blocks storing the file data and a timestamp corresponding to the stored data. In response to creating a file, data corresponding block map is maintained. In addition, a new entry is created in the block map which identifies the newly allocated blocks. Further, an entry of the block map is updated to (i) identify the particular blocks to which the write was directed and (ii) include a timestamp corresponding to the time of the write.
摘要:
A method, system, and computer program product are provided to update file change log data to indicate that a change to a file in a file system has occurred. The file change log data are accessible for read access using a file system-independent operating system function. Applications can read, open, close, and seek data in the file change log using file system-independent operating system functions. The file change log data can be read by multiple applications simultaneously, even when data are being written to the file change log. Operations such as writing data to the file change log and renaming or deleting the file change log file itself are prevented when performed by an application rather than the file system. These prohibitions protect the file change log.
摘要:
A system and method for storing data. In one embodiment, a storage system includes a resource manager and a hierarchical entry tree describing storage entities of the storage system. At each given level of the tree higher than the bottom level, metadata entries summarize storage availability at a level below the given level. The resource manager receives a request to store data of a target size at a target location corresponding to a first portion of the entry tree and scans the entry tree to determine if contiguous, free storage entities of the target size are available at the target location. In response to determining that contiguous, free storage entities of the target size are not available at the target location, the resource manager scans portions of the entry tree outside the first portion to identify contiguous, free storage entities of the target size, where it stores the data.
摘要:
A method and system are provided for partitioning a file system. The system may include one or more server computer systems and a plurality of physical file systems. The physical file systems may be hosted by the one or more server computer systems. The physical file systems may be accessible to clients through a virtual file system having a single namespace. The virtual file system may include metadata which are partitioned across the plurality of physical file systems. The server computer systems may be configured to independently perform file system consistency checks on each of the physical file systems, in order to independently validate each partition of the metadata.
摘要:
A method, system, computer system, and computer-readable medium for maintaining up-to-date, consistent copies of primary data without the need to replicate modified data when the data were modified as a result of an operation that is not an application-driven write operation captured during replication. Selected storage management operations are performed on the primary and secondary data stores at points in time when the data are the same to ensure that the data stored within the data stores remain consistent. These selected storage management operations include operations that produce modified data stored in the primary data store, where a portion of the modified data are not replicated to a secondary node. Other types of storage management operations are selected to be performed on both the primary and secondary data stores, where the operations do not directly change data in the primary data store, but may affect data stored in the primary data store.
摘要:
Various embodiments of systems and methods are disclosed for initially synchronizing redundant data (e.g., a mirror, a replica, or a set of parity information) with an original volume. State information identifies which regions of the original volume are currently valid, and only valid regions of the original volume are used to generate the values of the redundant data during the initial synchronization. For example, if the redundant data is a set of parity information, synchronizing the redundant data involves calculating one or more parity values based on the valid regions of the volume. If the redundant data is a duplicate copy (e.g., a mirror or replica) of the volume, synchronizing the redundant data involves copying the valid regions of the volume to the duplicate copy of the volume. If the original volume includes any invalid regions, unnecessary copying and/or processing for those regions can be avoided during the initial synchronization.
摘要:
A virtual copy of data stored in a first memory is created in a second memory. Creating the virtual copy includes, in one embodiment, creating first and second tables in memory each one of which comprises a plurality of multibit entries. Each entry of the first table corresponds to a respective memory region of the first memory. Each entry of the second table corresponds to a respective memory region of the second memory. The first bit of the first and second tables indicates whether the corresponding memory region of the first and second memories, respectively, contains valid data. The second bit of the first and second tables indicates whether data in the corresponding memory region of the first and second memories, respectively, has been modified since the creation of the first and second tables, respectively.
摘要:
A method, system, and computer program product to enable a user to specify an intended use for a logical volume. The logical volume is configured using an application-specific template (also referred to as a user template) for an application, where the application-specific template satisfies the intended use. Rules from the application-specific template are stored with the logical volume in addition to or as part of the intent.
摘要:
In one embodiment of the method, first and second data volumes are created. Thereafter, a first data portion of the first data volume is overwritten with a first data portion of the second data volume. A second data portion of the first data volume is overwritten with a second data portion of the second data volume. In one embodiment, the first and second data portions of the first data volume are overwritten with the first and second data portions of the second data volume, respectively, in response to a command to restore or synchronize the data contents of the first data volume to the data contents of the second data volume. A virtual point-in-time (PIT) copy of the first data volume is created after overwriting the first data portion but before overwriting the second data portion.
摘要:
A system and method for controlling the creation of stable disk images. Data is transmitted to an application program interface identifying the storage object. The application program interface returns a list with one or more methods appropriate for quiescing or for freezing the storage object.