A portion of the disclosure of this patent document contains command formats and other computer language listings, all of which are subject to copyright protection. The copyright owner, EMC Corporation, has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The invention relates generally to handling of data in a data storage environment, and more particularly to a system and method for performing a restore operation efficiently in such an environment.
As is known in the art, computer systems which process and store large amounts of data typically include a one or more processors in communication with a shared data storage system in which the data is stored. The data storage system may include one or more storage devices, usually of a fairly robust nature and useful for storage spanning various temporal requirements, e.g. disk drives. The one or more processors perform their respective operations using the storage system. To minimize the chance of data loss, the computer systems also can include a backup storage system in communication with the primary processor and the data storage system. Often the connection between the one or more processors and the backup storage system is through a network in which case the processor is sometimes referred to as a xe2x80x9cbackup client.xe2x80x9d
The backup storage system can include a backup storage device (such as tape storage or any other storage mechanism), together with a system for placing data into the storage device and recovering the data from that storage device. To perform a backup, the client copies data from the shared storage system across the network to the backup storage system. Thus, an actual data file may be communicated over the network to the backup storage device.
The shared storage system corresponds to the actual physical storage. For the client to write the backup data over the network to the backup storage system, the client first converts the backup data into file data i.e., the client retrieves the data from the physical storage system level, and converts the data into application level format (e.g. a file) through a logical volume manager level, a file system level and the application level. When the backup storage device receives the data file, the backup storage system can take the application level data file, and convert it to its appropriate file system level format for the backup storage system. The data can then be converted through the logical volume manager level and into physical storage.
A xe2x80x9crestorexe2x80x9d operation is analogous to a backup operation but the flow of data is typically from the backup device to the computer system from where it was backed up originally. For performance improvements, a backup storage architecture in which a direct connection is established between the shared storage system and the backup storage system was conceived. Such a system is described in U.S. Pat. No. 6,047,294, assigned to assignee of the present invention, and entitled Logical Restore from a Physical Backup in Computer Storage System and herein incorporated by reference. However, even with such a system a restore operation consumes a significant amount of time and ties up computer resources, e.g. server. Not insignificant is the amount of time that such an operation makes a resource such as an application inoperable or requires computer professionals to wait for such an operation to be completed.
What is needed is a way to make the restore operation more efficient in terms of time in which resources such as software, servers, and humans have to wait for it to complete its operation. Further it would be an advantage if such an objective could be achieved without adding other cumbersome tasks or significant overhead to computer system""s and computer professional""s existing workload.
The present invention is a system and method for restoring data in a manner that reduces wait time of associated resources.
The method of this invention enables efficient performance of a restore operation is a data storage environment. The method includes the steps of receiving a request to perform an I/O operation on at least one track of data and in response to receiving the request to perform an I/O operation determining whether a restore is in progress. The method further includes the step of determining whether the at least one track of data is indicated as having a protected status from the I/O operation being carried out on the at least one track. And the method includes the step of selectively either carrying out the I/O operation or accounting for the I/O operation separate from the at least one track of data.
In an alternative embodiment, the invention includes a system for carrying out method steps. In another alterative embodiment, the invention includes a program product for carrying out the method steps.