Multi-stream restore system and method

A computer system and process restores files on multiple disk drives from a plurality of backup files on a plurality of media types and at a plurality of locations. The system receives at a processor a restore command, and partitions the restore command into two or more sub-jobs. The system determines a location for each of the plurality of media types, and matches each sub-job with a different media type at a different location. The system then restores the files from each different media type at a different location to the multiple disk drives in parallel.

TECHNICAL FIELD

The present invention relates to a system and method to restore computer files from backups, and in an embodiment, but not by way of limitation, to systems and methods to restore computer files from backups that reside on multiple sources.

BACKGROUND

Backing up computer files and databases many a time is done on multiple targets, thereby resulting in more than one copy of a backup. Such multiple backups can reside on different media such as an inline copy, a disk drive, or a tape. Additionally, the process of backing up files to these different media can include a disk to disk to tape (D2D2T) process, a disk to tape to tape (D2T2T) process, and a grandfather-father-son process.

SUMMARY

In an embodiment, a computerized process restores files on multiple disk drives from a plurality of backup files on a plurality of media types and at a plurality of locations. The computerized process first receives a restore command. The process then partitions the restore command into two or more sub-jobs. The process determines a location for each of the plurality of media types, and matches each sub-job with a different media type at a different location. The files are restored from each different media type at a different location to the multiple disk drives in parallel.

DETAILED DESCRIPTION

Embodiments of the invention include features, methods or processes embodied within machine-executable instructions provided by a machine-readable medium. A machine-readable medium includes any mechanism which provides (i.e., stores and/or transmits) information in a form accessible by a machine (e.g., a computer, a network device, a personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.). In an exemplary embodiment, a machine-readable medium includes volatile and/or non-volatile media (e.g., read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, etc.).

Such instructions are utilized to cause a general or special purpose processor, programmed with the instructions, to perform methods or processes of the embodiments of the invention. Alternatively, the features or operations of embodiments of the invention are performed by specific hardware components which contain hard-wired logic for performing the operations, or by any combination of programmed data processing components and specific hardware components. Embodiments of the invention include digital/analog signal processing systems, software, data processing hardware, data processing system-implemented methods, and various processing operations, further described herein.

A number of figures show block diagrams of systems and apparatus of embodiments of the invention. A number of figures show flow diagrams illustrating systems and apparatus for such embodiments. The operations of the flow diagrams will be described with references to the systems/apparatuses shown in the block diagrams. However, it should be understood that the operations of the flow diagrams could be performed by embodiments of systems and apparatus other than those discussed with reference to the block diagrams, and embodiments discussed with reference to the systems/apparatus could perform operations different than those discussed with reference to the flow diagrams.

In many file backup situations, when a backup is made, the backup is written to more than one location, and the different locations can include different media types such as an inline copy, a disk drive, or a tape copy. An embodiment of the present disclosure determines the best, i.e. fastest, manner in which to restore/retrieve backed up data. In an embodiment, when a user requests that a file be restored, the system will first partition the restore command into two or more sub-jobs. This partitioning can be based on several factors including the size of the backup and/or the target file, disk partitions of the backup and/or target file, and other pertinent factors. The system will then determine all of the available media types and the locations of those media types for the particular file to be restored. This can be determined by reading a database that maintains this information. The sub-jobs are then each matched with a particular media type at a particular location, and the file is restored by each sub-job working in parallel.

An embodiment of the present disclosure also creates a cyclical redundancy check (CRC), or some other type of check, when a volume and/or file is backed up. This check includes a timestamp or indicator, and is maintained in the database for each file and for each volume (such as C drive, D drive, etc.) for every file that is backed up. A check indicator is also appended to each backup file and/or volume on the actual backup media. Then, when a file is restored, the check indicator from the volume level to the file level is compared on the files and/or volumes in the database to the check indicator on the files and/or volumes from the backup media. In this manner it can be determined which backup is the correct one to use for a restore. Also, if a file and/or volume needs to be restored from a past history, that is, not the latest backup, the check indicator that indicates that particular version of the file and/or volume is compared with the check indicators on the backup media to locate the correct backup. This provides the capability to restore a history file and/or volume using a multi-stream restore since different backup media can be used in parallel fashion.

FIG. 1is a flowchart of an example process100for restoring computer files from backup files that are resident on multiple sources and/or locations.FIG. 1includes a number of process blocks105-192that are identified by unique numbers. Though arranged serially in the example ofFIG. 1, other examples may reorder the blocks, omit one or more blocks, and/or execute two or more blocks in parallel using multiple processors or a single processor organized as two or more virtual machines or sub-processors. Moreover, still other examples can implement the blocks as one or more specific interconnected hardware or integrated circuit modules with related control and data signals communicated between and through the modules. Thus, any process flow is applicable to software, firmware, hardware, and hybrid implementations.

Referring now toFIG. 1, the computerized process100is a process for restoring files on multiple disk drives from a plurality of backup files on a plurality of media types and at a plurality of locations. At105, a restore command is received at a processor. At110, the restore command is partitioned into two or more sub-jobs. At115, a location is determined for each of the plurality of media types. At120, each sub-job is matched with a different media type at a different location. After the matching, at125, the files are restored from each different media type at a different location to the multiple disk drives. The restoration of the files is performed in parallel.

Continuing with the process100inFIG. 1, at130, the plurality of media types on which a backup or backups can be found includes an inline copy, a disk copy, and a tape copy. The backups can be found at these different media types because many a time, during a normal back procedure, as indicated at135, the backup copies are as a matter of course written to one or more of an inline copy, a disk copy, and a tape copy. The writing of a backup to these different media can be accomplished using one or more of a disk to disk to tape (D2D2T) process, a D2T2T (disk to tape to tape) process, and a grandfather-father-son (GFS) process. Since these backup protocols are ubiquitous in data processing environments, the multiple copies from which to restore files are readily available.

At140, a user interface is generated to permit a user to supply parameters to control the restoring of the files. At145, it is noted that the parameters can include a logical location, a size, and a partition of a disk drive to be restored, a size of one or more files to be restored, and one or more media types and logical locations of backup files to be restored. At150, the multiple disk drives are restored based on the user-supplied parameters.

At155, a previous backup copy is accessed when a current backup copy is not available. A current backup copy may not be available for example because it is opened by another process, or because a backup tape has been misplaced or lost. A previous backup copy may also be accessed because an earlier history backup is required. At160, a cyclical redundancy check (CRC) or other check is performed to determine if the data on the previous backup copy and the data on the current backup copy are the same. That is, is this backup version the one that is required. Then, at165, the data is restored using the previous backup copy when the cyclical redundancy check or other check indicates that the data on the previous backup copy and the data on the current backup copy are the same (indicating this is the correct version to restore).

At170, input relating to the formation of the sub-jobs is received, and at175, the sub-jobs are partitioned based on the input. At180, a cyclical redundancy check (CRC) is performed on a backup file on a logical location of a media type, and at182, data from a different logical location of a media type is restored when the CRC fails.

At184, a first sub-job is assigned to a backup location. At186, a cyclical redundancy check or other check is performed on the backup location and a previous backup of the backup location. At188, a second sub-job is assigned to the previous backup when the cyclical redundancy check or other check of the backup location and the previous backup are the same. In some instances, as indicated at190, the second sub-job is assigned to the previous backup when the previous backup location is the only backup of a particular file. This could occur if the backup tape is misplaced or lost, and the only option is to access the previous backup. At192, other backup locations are searched when the cyclical redundancy check or other check of the backup location and the previous backup location are not the same.

FIG. 2illustrates a block diagram of an example embodiment of a process200to restore data files onto a multi-drive system from a plurality of backup locations. As illustrated at205, a plurality of files are to be restored on a multi-drive system. The multiple drives are identified as the C, D, E, F, and G drives. At210, several restore sub-jobs are created. In the example ofFIG. 2, these sub-jobs are created based on parameters or options supplied by a user. As noted previously, these parameters generally relate to the size and location of the disk drives and the size and location of the backup sources. These parameters can also include a specific version of a file and/or volume to be restored.

As illustrated inFIG. 2, at215, sub-job1is created to restore the C drive data. In the example ofFIG. 2, the data to restore is located on a tape media that is referred to as Media A. At220, sub-job2is created to restore data to the D drive. According toFIG. 2, this data can be found on a disk staging device B. At225, sub-job3is created to restore data to the E drive. This data is retrieved from a tape copy media A′, which is a copy or previous backup of the backup Media A.

At230, sub-job4is created to restore data to the F drive. As indicated at230, the user has specified that the backup for the F drive be taken from a previous backup of the F drive. However, before this can be done, a CRC or other check is performed on the backup and previous backup to verify that there are no differences between the two backups. A user can also specify a previous backup simply because that is the version of the file that the user would like to restore. In such a case, the CRC or other check must indicate that this previous backup is the version that the user is seeking. If the CRC check fails at230, then as indicated at235, a makeup sub-job is created that will search other media for the same file or files. At240, sub-job5is created to restore data to the G drive. As indicated at240, this data is retrieved from a related snapshot. As indicated at245, a makeup job is created if a CRC check of the related snapshot failed, and other media will be searched for the needed files.

When restoring, if a volume check is correct, then every file in the volume is the correct version for the restore, and the entire volume can be restored. However, if the check at the volume level fails, each file in the volume will be checked. If a file's check is correct, then that file can be restored. If a file's check fails, a makeup job is created for this file and all other files in the volume that failed the check. The makeup job is only for the files that did not pass the check; the makeup job is not for the entire volume. In an embodiment, since individual file checks can consume a good deal of time (when the volume check fails), the file check can be bypassed. When the bypass of the file check is enabled, the makeup job will simply search other media when the volume check fails.

In the embodiment shown inFIG. 3, a hardware and operating environment is provided that is applicable to any of the servers and/or remote clients shown in the other Figures.

As shown inFIG. 3, one embodiment of the hardware and operating environment includes a general purpose computing device in the form of a computer20(e.g., a personal computer, workstation, or server), including one or more processing units21, a system memory22, and a system bus23that operatively couples various system components including the system memory22to the processing unit21. There may be only one or there may be more than one processing unit21, such that the processor of computer20comprises a single central-processing unit (CPU), or a plurality of processing units, commonly referred to as a multiprocessor or parallel-processor environment. In various embodiments, computer20is a conventional computer, a distributed computer, or any other type of computer.

The system bus23can be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory can also be referred to as simply the memory, and, in some embodiments, includes read-only memory (ROM)24and random-access memory (RAM)25. A basic input/output system (BIOS) program26, containing the basic routines that help to transfer information between elements within the computer20, such as during start-up, may be stored in ROM24. The computer20further includes a hard disk drive27for reading from and writing to a hard disk, not shown, a magnetic disk drive28for reading from or writing to a removable magnetic disk29, and an optical disk drive30for reading from or writing to a removable optical disk31such as a CD ROM or other optical media.

The hard disk drive27, magnetic disk drive28, and optical disk drive30couple with a hard disk drive interface32, a magnetic disk drive interface33, and an optical disk drive interface34, respectively. The drives and their associated computer-readable media provide non volatile storage of computer-readable instructions, data structures, program modules and other data for the computer20. It should be appreciated by those skilled in the art that any type of computer-readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs), redundant arrays of independent disks (e.g., RAID storage devices) and the like, can be used in the exemplary operating environment.

A plurality of program modules can be stored on the hard disk, magnetic disk29, optical disk31, ROM24, or RAM25, including an operating system35, one or more application programs36, other program modules37, and program data38. A plug in containing a security transmission engine for the present invention can be resident on any one or number of these computer-readable media.

A user may enter commands and information into computer20through input devices such as a keyboard40and pointing device42. Other input devices (not shown) can include a microphone, joystick, game pad, satellite dish, scanner, or the like. These other input devices are often connected to the processing unit21through a serial port interface46that is coupled to the system bus23, but can be connected by other interfaces, such as a parallel port, game port, or a universal serial bus (USB). A monitor47or other type of display device can also be connected to the system bus23via an interface, such as a video adapter48. The monitor47can display a graphical user interface for the user. In addition to the monitor47, computers typically include other peripheral output devices (not shown), such as speakers and printers.

The computer20may operate in a networked environment using logical connections to one or more remote computers or servers, such as remote computer49. These logical connections are achieved by a communication device coupled to or a part of the computer20; the invention is not limited to a particular type of communications device. The remote computer49can be another computer, a server, a router, a network PC, a client, a peer device or other common network node, and typically includes many or all of the elements described above I/0 relative to the computer20, although only a memory storage device50has been illustrated. The logical connections depicted inFIG. 3include a local area network (LAN)51and/or a wide area network (WAN)52. Such networking environments are commonplace in office networks, enterprise-wide computer networks, intranets and the internet, which are all types of networks.

When used in a LAN-networking environment, the computer20is connected to the LAN51through a network interface or adapter53, which is one type of communications device. In some embodiments, when used in a WAN-networking environment, the computer20typically includes a modem54(another type of communications device) or any other type of communications device, e.g., a wireless transceiver, for establishing communications over the wide-area network52, such as the internet. The modem54, which may be internal or external, is connected to the system bus23via the serial port interface46. In a networked environment, program modules depicted relative to the computer20can be stored in the remote memory storage device50of remote computer, or server49. It is appreciated that the network connections shown are exemplary and other means of, and communications devices for, establishing a communications link between the computers may be used including hybrid fiber-coax connections, T1-T3 lines, DSL's, OC-3 and/or OC-12, TCP/IP, microwave, wireless application protocol, and any other electronic media through any suitable switches, routers, outlets and power lines, as the same are known and understood by one of ordinary skill in the art.