摘要:
An architecture and apparatus for atomic operations across multi-volume or multi-LUNs in a data storage environment. It is difficult to manage data storage and replication operations occurring across such multi-LUNs. The architecture and apparatus embodiments of the invention overcome these deficiencies and facilitate data storage management and replication operations through library initializations in response to host I/O requests to complete atomic operations. Accordingly, the invention ensures the integrity of the data being managed without introducing significant cost or overhead.
摘要:
A method system and program product for atomic operations across multi-volume or multi-LUNs in a data storage environment. It is difficult to manage data storage and replication operations occurring across such multi-LUNs. The method system and program product embodiments overcome these deficiencies and facilitate data storage management and replication operations through library initializations in response to host I/O requests. Accordingly, the invention ensures the integrity of the data being managed without introducing significant cost or overhead.
摘要:
A system, device, and method for providing mutual exclusion for computer system resources utilizes a lock mechanism in which a process that does not own a particular resource creates a lock for the resource upon receiving an inquiry from another process. The lock may be a full instantiation of a lock or a partial instantiation of a lock. In either case, the lock indicates, among other things, the owner process for the resource. When the non-owner process requires access to the resource, the non-owner process uses the lock to determine the owner process and sends a request to the owner process requesting access to the resource.
摘要:
Methods, systems, and computer program products for preserving atomic writes to disk arrays are disclosed. According to one method, portions of a file are stored in paired locations on a disk array such that a first location of a location pair for a file portion stores scratch data for the file portion and a second portion of the location pair for the file portion stores valid data for the file portion. A bitmap is stored on the disk array. The bitmap has bits indicating whether valid data for each file portion resides in the first or the second location for its respective location pair. A write request to write data to a portion of the file being less than the entire file is received. The bitmap indicates that valid data for the portion of the file to be written to resides in a first memory location of one of the location pairs on the disk array. In response to the write request, the bitmap is copied to memory, the data for the portion of the file requested to be modified is copied from the first location of the one location pair to a second location of the one location pair on the disk array without copying the entire file and modifying the data in the second location based on the data to be written. The bitmap stored in memory is modified to indicate that valid data for the portion of the file resides in the second location of the one location pair and that scratch data for the portion of the file resides in the first location on the disk array. A request to save the modification is received, and, in response to the request to save the modified data, the bitmap stored on the disk array is replaced with the modified bitmap.
摘要:
A method is used in managing database access. A framework is provided for translating versioned data between memory and persistent storage. Based on the framework, read and write requests that access records in a database are translated. Based on the framework, it is made to appear that the database is a different version of the database.