阅读说明：本技术 存储无关的应用程序一致性快照和复制 (Storage independent application consistent snapshots and replication ) 是由 R·戈温丹 于 2018-03-30 设计创作，主要内容包括：提供存储无关的应用程序一致性快照和复制。在各种实施方案中,向卷快照服务发出快照命令。由此指示所述卷快照服务将一个或多个应用程序置于备份模式。从所述卷快照服务检索将要快照的LUN的清单。向所述清单上的LUN下层的一个或多个存储系统发出快照命令。在对所述一个或多个存储系统完成所述快照命令之后,将控制交还给所述卷快照服务。(Storage independent application consistent snapshots and replication are provided. In various embodiments, a snapshot command is issued to a volume snapshot service. Thereby instructing the volume snapshot service to place one or more applications in backup mode. A list of LUNs to be snapshotted is retrieved from the volume snapshot service. And issuing a snapshot command to one or more storage systems underlying the LUN on the manifest. Returning control to the volume snapshot service after the snapshot command is completed to the one or more storage systems.)

1. A method, the method comprising:

issuing a snapshot command to a volume snapshot service and thereby instructing the volume snapshot service to place one or more applications in a backup mode;

retrieving a list of LUNs to be snapshotted from the volume snapshot service;

issuing a snapshot command to one or more storage systems underlying the LUN on the manifest;

returning control to the volume snapshot service after the snapshot command is completed to the one or more storage systems.

2. The method of claim 1, wherein the one or more applications comprise a database application.

3. The method of claim 1, wherein the LUN to be snapshotted corresponds to one or more volumes supporting the one or more applications.

4. The method of claim 1, further comprising:

the LUN is copied from the one or more storage systems to a secondary storage device by a point-in-time copy.

5. A system, the system comprising:

one or more storage systems;

a computing node comprising a computer-readable storage medium having program instructions embodied therein, the program instructions being executable by a processor to cause the processor to perform a method comprising:

issuing a snapshot command to a volume snapshot service and thereby instructing the volume snapshot service to place one or more applications in a backup mode;

retrieving a list of LUNs to be snapshotted from the volume snapshot service;

issuing a snapshot command to the one or more storage systems that underlie the LUN on the manifest;

returning control to the volume snapshot service after the snapshot command is completed to the one or more storage systems.

6. The system of claim 1, wherein the one or more applications comprise a database application.

7. The system of claim 1, wherein the LUN to be snapshotted corresponds to one or more volumes backed up for the one or more applications.

8. The system of claim 1, further comprising:

the LUN is copied from the one or more storage systems to a secondary storage device by a point-in-time copy.

9. A computer program product for snapshots, the computer program product comprising a computer-readable storage medium having program instructions embodied therein, the program instructions being executable by a processor to cause the processor to perform a method comprising:

issuing a snapshot command to a volume snapshot service and thereby instructing the volume snapshot service to place one or more applications in a backup mode;

retrieving a list of LUNs to be snapshotted from the volume snapshot service;

issuing a snapshot command to one or more storage systems underlying the LUN on the manifest;

returning control to the volume snapshot service after the snapshot command is completed to the one or more storage systems.

10. The computer program product of claim 9, wherein the one or more applications comprise a database application.

11. The computer program product of claim 9, wherein the LUN to be snapshotted corresponds to one or more volumes backed up for the one or more applications.

12. The computer program product of claim 9, the method further comprising:

the LUN is copied from the one or more storage systems to a secondary storage device by a point-in-time copy.

Technical Field

Embodiments of the present disclosure relate to snapshots, and more particularly, to storage independent application consistent snapshots and replication.

Disclosure of Invention

According to embodiments of the present disclosure, methods and computer program products for snapshots are provided. In various embodiments, a snapshot command is issued to a volume snapshot service. Thereby instructing the volume snapshot service to place one or more applications in backup mode. A list of LUNs to be snapshotted is retrieved from the volume snapshot service. And issuing a snapshot command to one or more storage systems underlying the LUN on the manifest. Returning control to the volume snapshot service after the snapshot command is completed to the one or more storage systems.

In some embodiments, the one or more applications include a database application. In some embodiments, the LUN to be snapshot corresponds to one or more volumes supporting the one or more applications. In some embodiments, the LUN is copied from the one or more storage systems to the secondary storage system by a point-in-time copy.

Drawings

Fig. 1 illustrates a system for providing snapshots according to an embodiment of the present disclosure.

FIG. 2 illustrates agent interactions within a system according to the present disclosure.

Fig. 3 illustrates a system for providing snapshots according to an embodiment of the present disclosure.

Fig. 4 illustrates a snapshot method according to an embodiment of the present disclosure.

Fig. 5 depicts a compute node according to an embodiment of the present disclosure.

Detailed Description

The Windows VSS framework can be used to provide application consistent snapshots on Windows. In such cases, the VSS snapshot provider is used to take the snapshot. Windows may provide native software snapshot functionality where each storage system vendor is responsible for taking snapshots of its storage system. Various storage system vendors may provide providers for taking snapshots on a primary storage system. However, to create secondary copies, the same functionality is not supported in the various storage systems. Some storage systems may allow copying of the primary snapshots to the secondary storage system. However, many vendors only support volume replication, and do not replicate the snapshot. This limits the ability to create on-site, application-consistent copies on the secondary storage system.

The present disclosure addresses this limitation as well as other limitations of alternative solutions for storage arrays. The present disclosure provides systems and methods that work with any storage system to generate in-place, application-consistent snapshots on primary and secondary storage systems.

In various embodiments, application consistency snapshots are created and replication of in-place copies on primary and secondary storage systems is provided regardless of their underlying replication technology. Various alternative storage system solutions only support the creation of primary copies on the storage system and are not designed to create secondary copies.

The snapshot provides a read-only copy of the data set that was frozen at some point in time while allowing the application to continue writing its data. This allows high data availability systems to perform backups without stopping. Some snapshot implementations may create a snapshot at O (1) time. Thus, the time and I/O required to create a snapshot does not increase with the size of the data set. The time and I/O required to make a direct backup is proportional to the size of the data set. In some systems, once an initial snapshot of a data set is taken, subsequent snapshots will copy only the changed data and reference the initial snapshot using a pointer system. This pointer-based snapshot method consumes less disk capacity than repeatedly cloning a data set.

In NTFS, access to snapshots is provided by volume shadow copy service (VSS) in Windows XP and Windows Server 2003 and by shadow copy in Windows Vista. VSS allows taking manual or automatic backup copies or snapshots of a computer file or volume even though the file or volume is in use. This is implemented as a Windows service called a shadow copy service. Shadow copies may be created on local and external (removable or network) volumes by any Windows component using this technology.

The core component of shadow copying is the volume shadow copy service, which starts and monitors the snapshot creation process. The component that performs all necessary data transfers is called the provider. Software and hardware providers may thus be provided and registered with the shadow copy service. Each provider has a maximum time for completing snapshot creation, which in some embodiments is 10 seconds.

The shadow copy service also accommodates pluggable writers. As described above, the goal of shadow copies is to create consistent, reliable snapshots. In some cases, it may not be sufficient to complete all pending file change operations. It may be necessary to complete a series of interrelated changes to several related files. For example, when a database application transfers a piece of data from one file to another, it needs to delete the piece of data from the source file and create the piece of data in the target file. Thus, to maintain consistency, a snapshot must not be created between the first deletion and subsequent creations. The application-specific writer is responsible for enforcing this semantic consistency. In some embodiments, the pluggable writer has 60 seconds to establish the backup security state before the provider starts snapshot creation.

In a computer storage system, a logical unit number or LUN is a number used to identify a logical unit, which is a device addressed by a SCSI protocol or a storage area network protocol that encapsulates SCSI, such as fibre channel or iSCSI. A LUN may be used for many devices that support read/write operations, such as tape drives, but is mostly used to refer to a logical disk as created on a SAN. The term LUN may also be used to refer to the logical disk itself.

Systems and methods according to the present disclosure provide a general-purpose, in-place snapshot provider that can support any storage system. Further, the systems and methods provided herein enable storage independent snapshot-in-place providers.

Referring now to fig. 1, a system for providing snapshots in accordance with an embodiment of the present disclosure is shown. Application 101 (application a) includes database 102 (database a). Database 102 maintains its files on LUN A103 and LUN B104. Specifically, the database file is stored on LUN A103, while the log file is stored on LUN B104. LUN A103 is mapped from storage system A105, and LUN B104 is mapped from storage system B106. In this example, storage system A105 is from vendor X, while storage system B106 is from vendor Y. Thus, the application database is hosted on two volumes supported by LUNs provided by different storage system vendors.

During copy creation, data protection software (e.g., ECX) according to the present disclosure injects VSS requesters and VSS snapshot providers into the Windows VSS system. The data protection software discovers the application configuration and storage system layout and issues snapshot commands to the VSS requester. The VSS requestor on the Windows system in turn requests the VSS framework to take a snapshot of the application database. The VSS framework will contact the writer of the application and place the application in backup mode and request the VSS snapshot provider to take a snapshot.

The VSS snapshot provider contacts the data protection software to inform it of the list of LUNs that a snapshot or copy is to be taken. At this point, the data protection software will issue a snapshot or copy command to storage system A105 for LUN A103 and a snapshot or copy command to storage system B106 for LUN B104, depending on the storage workflow defined as part of the policy. After the snapshot creation or the establishment of the copy relationship is successfully completed, the data protection software will transfer control back to the VSS snapshot provider. The process ensures that this will be done within the 10 second window enforced by Windows.

The VSS will request the writer to take the application out of backup mode and return control to the requester. The requestor forwards this back to the data protection software.

Referring now to FIG. 2, there is shown an agent interaction within a system according to the present disclosure, specifically between data protection software, a VSS requester and a VSS snapshot provider. This figure presents how the communication and layout between data protection software 201 (e.g., ECX) and Windows (or other operating systems) makes application snapshots and duplicate copies for LUNs from two storage systems (e.g., a105 and B106).

In general, the Volume Snapshot Service (VSS) allows for taking manual or automatic backup copies or snapshots of computer files or volumes even though the files or volumes are in use. The volume snapshot service may be implemented as a Windows service or comparable component on another operating system. In general, VSS operates at the block level volume. However, it will be appreciated that the present disclosure may be applied to file level backups. In general, a snapshot is a read-only point-in-time copy of a volume. Snapshots allow a consistent backup of volumes to be created, ensuring that the contents do not change and are not locked when the backup is performed.

Within the VSS architecture 202, the components that perform all necessary data transfers are referred to as providers. A software or hardware provider 204 may register with the VSS 202, which starts and monitors the snapshot creation process. The VSS writer 205 may also register with VSS 202. In some cases, a consistent, reliable snapshot cannot be generated by completing all pending file change operations. Thus, it may be necessary to complete a series of interrelated changes to several related files. For example, when a database application transfers a piece of data from one file to another, the database application may delete the piece of data from the source file and create the piece of data in the target file. Thus, a snapshot will not occur between the first deletion and subsequent creation. The snapshot should be taken before deletion or after creation. The task of enforcing this semantic consistency is handed over to the VSS writer 205. Each writer is application specific and has a fixed time for establishing a backup security state before the provider starts snapshot creation. In some embodiments, the time limit is 60 seconds. If VSS does not receive an acknowledgement of success from the corresponding writer within this time, the operation fails.

According to various embodiments of the present disclosure, data protection software 201 (e.g., ECX) sends a snapshot request to VSS 202 via VSS requester 203. In some embodiments, the request includes an application and a volume identifier. The VSS snapshot provider 204 returns LUN data, including a LUN identifier. The above process establishes an application consistent copy point on the primary or secondary storage system that can be used for recovery, DevOp, or logical analysis using native array capabilities, for example.

Referring now to fig. 3, a system for providing snapshots in accordance with an embodiment of the present disclosure is shown. In various embodiments, a data protection software/management server (e.g., ECX)301 creates an application consistency snapshot by communicating with a database server 302 … 303. In some embodiments, database server 302 … 303 may be a SQL server. In this example, database server 302 … 303 supports application 304. Database server 302 … 303 is in turn supported by one or more source volumes or snapshots 305 located on a primary physical storage system 306. At 311, VSS as described above places application 304 in backup mode. At 312, the VSS hardware provider calls the management server 301 to take a storage snapshot or duplicate point-in-time copy. As described above, in some embodiments, the underlying operating system provides a10 second window for this operation. At 313, the management server 301 calls the primary physical storage system 306 to create a snapshot. At 314, the management server 301 calls the secondary physical storage system 307 to replicate the volume from the primary storage system through point-in-time copy. The replicated volumes and snapshots 308 are supported by the physical secondary storage system 307.

Once a snapshot is created or replication is initiated, control is handed back to the VSS hardware provider. The VSS hardware provider will hand the call back to the VSS requester (e.g., ECX agent). The management server 301 catalogs the master snapshot or the replicated volume snapshots.

The management server (e.g., ECX) as set forth above simplifies SQL server copy management by enabling administrators to schedule application-consistent copy creation, cloning, and recovery by minutes rather than hours or days. This copy management takes advantage of the snapshot and replication features of the underlying storage platform to efficiently and quickly create, replicate, clone, and restore copies of a database (e.g., SQL server) in time and space.

Referring now to fig. 4, a snapshot method is shown, according to an embodiment of the present disclosure. At 401, a snapshot command is issued to a volume snapshot service. Thereby instructing the volume snapshot service to place one or more applications in backup mode. At 402, a list of LUNs to be snapshot is retrieved from the volume snapshot service. At 403, a snapshot command is issued to one or more storage systems underlying the LUN on the manifest. At 404, after the snapshot command is completed to the one or more storage systems, control is returned to the volume snapshot service.

Referring now to FIG. 5, a schematic diagram of an example of a compute node is shown. The computing node 10 is only one example of a suitable computing node and is not intended to suggest any limitation as to the scope of use or functionality of the embodiments described herein. Regardless, the computing node 10 is capable of being implemented and/or performing any of the functionality set forth above.

In the computing node 10, there is a computer system/server 12 that may be used in many other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with computer system/server 12 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, distributed cloud computing environments that include any of the above systems or devices, and the like.

The computer system/server 12 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer system/server 12 may be implemented in a distributed cloud computing environment where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.

As shown in FIG. 5, the computer system/server 12 in the computing node 10 is shown in the form of a general purpose computing device. The components of computer system/server 12 may include, but are not limited to, one or more processors or processing units 16, a system memory 28, and a bus 18 that couples various system components including the system memory 28 to the processors 16.

Bus 18 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

Computer system/server 12 typically includes a variety of computer system readable media. Such media can be any available media that is accessible by computer system/server 12 and includes both volatile and nonvolatile media, removable and non-removable media.

The system memory 28 may include computer system readable media in the form of volatile memory, such as Random Access Memory (RAM)30 and/or cache memory 32. The computer system/server 12 may also include other removable/non-removable, volatile/nonvolatile computer system storage media. By way of example only, a storage system 34 may be provided for reading from and writing to non-removable, non-volatile magnetic media (not shown and commonly referred to as a "hard drive"). Although not shown, a magnetic disk drive for reading from and writing to a removable, nonvolatile magnetic disk (e.g., a "floppy disk") and an optical disk drive for reading from and writing to a removable, nonvolatile optical disk such as a CD-ROM, DVD-ROM, or other optical media may be provided. In such cases, each may be connected to bus 18 by one or more data media interfaces. As will be further depicted and described below, memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the disclosure.

A program/utility 40 having a set (at least one) of program modules 42 may be stored in memory 28, for example and without limitation, an operating system, one or more application programs, other program modules, and program data may also be stored in the memory. Each of the operating system, one or more application programs, other program modules, and program data, or some combination thereof, may include an implementation of a network environment. Program modules 42 generally implement the functions and/or methodologies of the embodiments described herein.

The computer system/server 12 may also communicate with: one or more external devices 14, such as a keyboard, pointing device, display 24, etc.; one or more devices that enable a user to interact with the computer system/server 12; and/or any device (e.g., network card, modem, etc.) that enables computer system/server 12 to communicate with one or more other computing devices. Some communication may occur via input/output (I/O) interfaces 22. Further, the computer system/server 12 may communicate with one or more networks, such as a Local Area Network (LAN), a global Wide Area Network (WAN), and/or a public network (e.g., the internet) via a network adapter 20. As depicted, the network adapter 20 communicates with the other components of the computer system/server 12 via the bus 18. It should be understood that although not illustrated, other hardware and/or software components may be used in conjunction with the computer system/server 12. Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archive storage systems, among others.

The present disclosure may include systems, methods, and/or computer program products. The computer program product may include a computer-readable storage medium (or media) having computer-readable program instructions thereon for causing a processor to implement aspects of the disclosure.

The computer readable storage medium may be a tangible device that can hold and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic memory device, a magnetic memory device, an optical memory device, an electromagnetic memory device, a semiconductor memory device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer-readable storage medium includes the following: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a Static Random Access Memory (SRAM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanical coding device such as a punch card or a raised structure with instructions recorded in a trench, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be construed as an essentially transient signal, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., optical pulses propagating through an optical cable), or an electrical signal propagating through a wire.

The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium to a corresponding computing/processing device or to an external computer or external storage device via a network (e.g., the internet, a local area network, a wide area network, and/or a wireless network). The network may include copper transmission cables, transmission fiber, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. The network adapter card or network interface in each computing/processing device receives computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium within the respective computing/processing device.

Computer-readable program instructions for carrying out operations of the present disclosure may be assembler instructions, Instruction Set Architecture (ISA) instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider). In some embodiments, an electronic circuit, including, for example, a programmable logic circuit, a Field Programmable Gate Array (FPGA), or a Programmable Logic Array (PLA), may execute the computer-readable program instructions by customizing the electronic circuit with state information of the computer-readable program instructions to perform aspects of the present disclosure.

Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.

These computer-readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer-readable storage medium having stored therein the instructions comprises an article of manufacture including instructions which implement an aspect of the function/act specified in the flowchart and/or block diagram block or blocks.

The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer, other programmable apparatus or other devices implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions described in the blocks may occur out of the order in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

The description of the various embodiments of the present disclosure is presented for purposes of illustration only and is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the described embodiments, the practical application, or technical improvements over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.