33 results about "Sparse file" patented technology

Read-only and read-write snapshot copies of a production file in a Unix-based file system are organized as a version set of file inodes and shared file blocks. Version pointers and branch pointers link the inodes. Initially the production file can have all its blocks preallocated or it can be a sparse file having only an inode and its last data block. A protocol is provided for creating read-only and read-write snapshots, deleting snapshots, restoring the production file with a specified snapshot, refreshing a specified snapshot, and naming the snapshots. Block pointers are marked with a flag indicating whether or not the pointed-to block is owned by the parent inode. A non-owner marking is inherited by all of the block's descendants. The block ownership controls the copying of indirect blocks when writing to the production file, and also controls deallocation and passing of blocks when deleting a read-only snapshot.

Sequential media reclamation is usually performed after portions of a sequential access volume's data are no longer needed and the unused portion of the volume exceeds a threshold. Improved sequential media reclamation is provided by using a sequential access disk volume (for example, a volume of a virtual tape library (VTL)) embodied as a sparse file. Reclamation of objects stored in the volume is accomplished by nulling out regions of the sparse file that contain the objects that are no longer needed. A replication method is also provided in which information about the objects stored in the sparse file (such as offset and length) is used during replication to enable the correct portions of a target volume (embodied as a sparse file) to be nulled out to match a source volume (also embodied as a sparse file).

A database view of a database is created which provides a transaction-consistent view of an existing database at a previous time. Each database view contains all the information needed to, along with the primary database, determine the contents of the primary database at a previous time. The database view consists of a side file corresponding to each data file in the primary database. The side files contain a copy of all data from the corresponding data file which has been changed since the database view was created. Sparse files may be used for the side files in order to conserve space. Page table data is kept in order to allow a quick determination as to whether the page from the primary database has been modified and the old version stored in the database view side file.

Embodiments are provided herein for an efficient database storage model, which utilizes sparse file features to efficiently store and retrieve data. The embodiments provide database algorithms that utilize the file system abstraction layer to hide the complexity of managing disk space while providing the database a linear and contiguous logical address space for holding multiple database objects. An embodiment method includes pre-allocating, in a logical sparse file, a plurality of segments fixed in size and contiguous at fixed offsets. Upon receiving a command to write database objects to the segments, the database objects are mapped to the segments in a database catalog. The method further includes interfacing with a file system to initialize storage medium space for writing the data objects to the segments at the fixed offsets.

Examples disclosed herein provide systems, methods, and software for avoiding data replication using sparse files. In one example, a method of using a sparse file to manage modifications to read-only files includes identifying an open file request on a computing system for a read-only file, and generating the sparse file corresponding to the read-only file. The method further includes identifying a modification to the read-only file and, responsive to identifying the modification, initiate a write to the sparse file based on the modification and identifying the write in a region map.

In some embodiments, a cyber security method for preventing unauthorized file modification by malicious software and the like, the file accessible to an authorized handler may include: receiving a first access request from a program, the first access request having a first instruction set for modifying data of the file; determining if the file is associated with the authorized handler; processing the first instruction set to produce first modification data; and generating an initial virtual file object comprising the first modification data. In further embodiments, a cyber security method for preventing unauthorized file modification by malicious software and the like, the file accessible to an authorized handler may include: processing an instruction set for modifying a file to produce modification data; generating a virtual file object comprising the modification data; and associating the virtual file object with the file by identifying the file as a sparse file.

The invention provides a method for edge caching of file data in a cross-domain virtual data space. Aiming at the requirement of efficient access to remote data in the cross-domain virtual data space and the IO bottleneck problem brought by the wide-area environment to upper-layer applications, the edge cache of file data is proposed. caching mechanism. Cache remote data close to the client and establish an edge cache to improve the overall performance of upper-layer applications accessing remote data, and further reduce data redundancy through cache sharing; edge cache establishes a memory-based file cache for small files, and for large files The file establishes a file system cache based on sparse files; the cache strategy based on the central read-write flag of file extension attributes is adopted to improve the consistency of data in the virtual data space; the cache replacement strategy based on file popularity ensures the performance and efficiency of the cache .

The invention provides a method and a device for quickly verifying the consistency of multi-duplicate storage. The method includes S1, judging data writing volumes of head files when systems are in idle states, creating snapshot files by the aid of I / O (input / output) redirection technologies when the volumes of data written into the head files reach 30% of the volumes of integral spare files at least, utilizing new head files with continuously written data as null comparison sparse files, computing hash values of the snapshot files and storing the hash values of the snapshot files as extended attributes; S2, carrying out snapshot operation on the head files once at intervals of preset time and comparing hash values of the new head files to the hash values of the snapshot files when the consistency of multi-duplicate data need to be timely verified. The method and the device have the advantages that characteristics of distributed block storage are combined with one another, the method for quickly detecting the consistency of multiple duplicates on the basis of snapshot technologies is proposed, hash value computation tasks are divided to be carried out in multiple time slots, accordingly, influence on normal reading and writing tasks of the systems can be prevented, and the multi-duplicate storage consistency verification speeds can be increased.

The invention relates to a method for redirecting iSCSI mounted volume to read and write data and a backup recovery system thereof, wherein the method includes 1) creating a temporary sparse file with the same size as the original sparse file; During the write operation, directly write the data to the temporary sparse file described in step 1); 3) when the read operation to the original sparse file is captured, read the data from the original sparse file and merge the data from the temporary sparse file The changed data is read out to obtain the latest data block; the backup recovery system includes a storage module of the native file system and a SCSI protocol analysis module. Compared with the prior art, the invention improves the reading and writing performance of the mounted volume, thereby better meeting the storage performance required by the application on the production system and improving the availability of the iSCSI mounted volume.