WO2015020636A1

WO2015020636A1 - Method and apparatus of storage system which stores information for relationship between logical volumes and operations

Info

Publication number: WO2015020636A1
Application number: PCT/US2013/053754
Authority: WO
Inventors: Akio Nakajima
Original assignee: Hitachi, Ltd.
Priority date: 2013-08-06
Filing date: 2013-08-06
Publication date: 2015-02-12

Abstract

Exemplary embodiments provide a way for the storage system to store and manage the information for relationship between logical volumes and operations. According to one aspect, a storage system comprises: a plurality of storage devices storing data; and a controller being operable to manage a plurality of logical units on the plurality of storage devices, and having a memory to store information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation. In some embodiments, the controller is operable, in response to an IO (Input/Output) request from a host computer, to use the stored information to identify one or more logical units involved in performing the IO request. The relationship type may be one of (i) task to logical unit, (ii) logical unit to task, or (iii) task to task.

Description

METHOD AND APPARATUS OF STORAGE SYSTEM WHICH STORES INFORMATION FOR RELATIONSHIP BETWEEN LOGICAL VOLUMES

AND OPERATIONS

BACKGROUND OF THE INVENTION [0001] The present invention relates generally to storage systems and, more particularly, to method and apparatus of a storage system which stores and manages information for relationship between logical volumes and storage operations.

[0002] Currently, storage administrators manually manage storage logical unit types such as backup, remote replication, and snapshot volume. For example, storage administrators manually manage the relationship, timing, or purpose of backup, since the storage controller does not have relationship information between internal volumes.

[0003] When the server administrator restores data, the server administrator does not have the necessary information to find backup volume. Hence, the server administrator communicates with the storage administrator to find the applicable backup volume. The storage administrator manages the relationship and volume attributes for many volumes to keep the relationship of volumes using the host server, backup volume for restore, etc.

BRIEF SUMMARY OF THE INVENTION [0004] Exemplary embodiments of the invention provide a way for the storage system to store and manage the information for relationship between logical volumes and operations. A storage array has relationship information between Logical Unit (LU) and storage operation or between storage operations. A storage array program records the relationship information in connection with a storage operation. The operation involves, for instance, a volume being created or deleted by the host or a volume being copied or replicated by the host or admin console. When the host wishes to access an internal volume which is not used by the host, the storage program provides the volume relationship information to the host and the host chooses to restore volume based on the operation-based volume relationship information. In this way, the server administrator has the relationship information of backup or LU configuration operation based on the volume and task operation. The server administrator can prevent mis-operation using the relationship information which includes alerts or messages when the operation involving one host affects 10 (input/output) of another host.

[0005] In accordance with an aspect of the present invention, a storage system comprises: a plurality of storage devices storing data; and a controller being operable to manage a plurality of logical units on the plurality of storage devices, and having a memory to store information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation.

[0006] In some embodiments, the controller is operable, in response to an 10 (Input/Output) request from a host computer, to use the stored information to identify one or more logical units involved in performing the 10 request. The information includes information of the host computer. The operation is one of create a logical unit, delete a logical unit, replicate a logical unit, create backup of a logical unit, create snapshot of a logical unit, or restore a logical unit. The relationship type is one of (i) task to logical unit, (ii) logical unit to task, or (iii) task to task.

[0007] In some embodiments, the operation for task to logical unit relationship type is one of create a logical unit, delete a logical unit, replicate to a destination logical unit, create snapshot to a destination logical unit, create backup to a destination logical unit, or restore to a destination logical unit. The operation for logical unit to task relationship type is one of replicate from a source logical unit, create snapshot from a source logical unit, create backup from a source logical unit, or restore from a backup logical unit. The operation for task to task relationship type is one of a backup operation task to a create backup logical unit task or a backup operation task to a replicate logical unit task.

[0008] In specific embodiments, the controller is operable, in a restore operation to restore backup data from a backup logical unit to a destination logical unit, to find one or more candidate backup logical units of the plurality of logical units from which to restore backup data based on the stored information, and store a list of the one or more candidate backup logical units found. The controller is operable, in a delete operation to delete a logical unit, to find one or more candidate logical units of the plurality of logical units to delete based on the stored information, and to notify alert to one or more host computers when deleting the one or more candidate logical units will affect 10 (input/output) requests involving the one or more host computers based on the stored information.

[0009] Another aspect of the invention is directed to a method of operating a storage system which includes a plurality of storage devices storing data. The method comprises: managing a plurality of logical units on the plurality of storage devices; and storing information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation.

[0010] Another aspect of this invention is directed to a computer program for operating a storage system which includes a plurality of storage devices storing data. The computer program comprises: code for managing a plurality of logical units on the plurality of storage devices; and code for storing information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation.

[0011] Another aspect of the invention is directed to a computer- readable storage medium storing a plurality of instructions for controlling a data processor to operate a storage system which includes a plurality of storage devices storing data, the plurality of instructions comprising:

instructions that cause the data processor to manage a plurality of logical units on the plurality of storage devices; and instructions that cause the data processor to store information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation.

[0012] These and other features and advantages of the present invention will become apparent to those of ordinary skill in the art in view of the following detailed description of the specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 illustrates an example of a hardware configuration of a computer system in which the method and apparatus of the invention may be applied.

[0014] FIG. 2 shows models of relationship diagrams between storage task and logical unit.

[0015] FIG. 3 shows an example of the configuration of the storage system.

[0016] FIG. 4 shows an example of the configuration of the host server.

[0017] FIG. 5 shows an example of a Logical Unit table.

[0018] FIG. 6 shows an example of a host table.

[0019] FIG. 7 shows an example of an operation table.

[0020] FIG. 8 shows an example of a LU relationship DB (Database) table.

[0021] FIG. 9 shows diagrams of create LU, delete LU, or configuration changed LU operation relationship from the host server or management console.

[0022] FIG. 10 shows diagrams backup, snapshot, or replicate LU operation relationship from the host server or management console.

[0023] FIG. 1 1 shows a diagram of a repeated or cascading backup operation.

[0024] FIG. 12 shows a diagram of a child operation relationship of a backup operation.

[0025] FIG. 13 shows an example of a flow diagram illustrating a storing operation task. [0026] FIG. 14 shows an example of a flow diagram illustrating a searching operation task.

[0027] FIG. 15 shows an example of a flow diagram illustrating a delete operation task.

DETAILED DESCRIPTION OF THE INVENTION

[0028] In the following detailed description of the invention, reference is made to the accompanying drawings which form a part of the disclosure, and in which are shown by way of illustration, and not of limitation, exemplary embodiments by which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. Further, it should be noted that while the detailed description provides various exemplary embodiments, as described below and as illustrated in the drawings, the present invention is not limited to the embodiments described and illustrated herein, but can extend to other embodiments, as would be known or as would become known to those skilled in the art. Reference in the specification to "one embodiment," "this embodiment," or "these

embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, and the appearances of these phrases in various places in the specification are not necessarily all referring to the same embodiment. Additionally, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details may not all be needed to practice the present invention. In other circumstances, well-known structures, materials, circuits, processes and interfaces have not been described in detail, and/or may be illustrated in block diagram form, so as to not unnecessarily obscure the present invention.

[0029] Furthermore, some portions of the detailed description that follow are presented in terms of algorithms and symbolic representations of operations within a computer. These algorithmic descriptions and symbolic representations are the means used by those skilled in the data processing arts to most effectively convey the essence of their innovations to others skilled in the art. An algorithm is a series of defined steps leading to a desired end state or result. In the present invention, the steps carried out require physical manipulations of tangible quantities for achieving a tangible result.

Usually, though not necessarily, these quantities take the form of electrical or magnetic signals or instructions capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, instructions, or the like. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as

"processing," "computing," "calculating," "determining," "displaying," or the like, can include the actions and processes of a computer system or other information processing device that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system's memories or registers or other information storage, transmission or display devices.

[0030] The present invention also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may include one or more general- purpose computers selectively activated or reconfigured by one or more computer programs. Such computer programs may be stored in a computer- readable storage medium including non-transitory medium, such as, but not limited to optical disks, magnetic disks, read-only memories, random access memories, solid state devices and drives, or any other types of media suitable for storing electronic information. The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs and modules in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform desired method steps. In addition, the present invention is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein. The instructions of the programming language(s) may be executed by one or more processing devices, e.g., central processing units (CPUs), processors, or controllers.

[0031] Exemplary embodiments of the invention, as will be described in greater detail below, provide apparatuses, methods and computer programs for a storage system which stores and manages information for relationship between logical volumes and storage operations.

[0032] Embodiment 1

[0033] FIG. 1 illustrates an example of a hardware configuration of a computer system in which the method and apparatus of the invention may be applied. The computer system includes storage systems 2 (2a, 2b), physical servers 3, and a network 4. The physical servers 3 each have a plurality of virtual machines (VMs) 5. The storage systems 2 each have a plurality of Logical Units (LUs) 21 (e.g., 21 a, 21 b, 21 w, 21 x, 21 y, 21 z). The physical server 3 or VM 5 is mapped to LU(s) 21 for relationship between host OS (Operating System) and data. The LU 21 is mapped to one or more other LUs 21 for relationship between copy source and copy destination for local backup, remote replication, snapshot, or migration.

[0034] FIG. 2 shows models of relationship diagrams between storage task and logical unit. FIG. 2a shows that a storage task 22 is dependent on a logical unit 21 (e.g., a task to LU relationship for creating, deleting, or copying a LU). FIG. 2b shows that a logical unit 21 is dependent on a storage task 22 (e.g., a LU to task relationship in which the LU is a source LU for the task). FIG. 2c shows that a storage task 22 is dependent on a storage task 22 (e.g., a task to task relationship in which a backup operation to a backup LU is dependent on a task of creating the backup LU).

[0035] FIG. 3 shows an example of the configuration of the storage system 2. FIG. 3a shows the hardware configuration. The physical storage system 2 includes a host l/F (Interface) which connects to the host, a CPU, a

Memory 33, a Disk l/F, HDDs (Hard Disk Drives) providing Logical Units 21 , and a Bus l/F (such as PCI, DDR, SCSI) which is connected to the above components. The controller of the storage system 2 includes the host l/F,

CPU, Memory 33, Disk l/F, and Bus l/F. FIG. 3b shows an example of the storage memory 33. It includes storage program 34, Logical Unit table 50,

Host table 60, Operation table 70, and LU relationship database 80.

[0036] FIG. 4 shows an example of the configuration of the host server

3. FIG. 4a shows the hardware configuration. The physical host 3 includes a

CPU, a Memory, a Disk l/F which connects to the storage system, HDD(s), and a Bus l/F (such as PCI, DDR, SCSI) which is connected to the above components. FIG. 4b shows an example of the host memory 43. It includes virtual machines 5 having application software 45 and OS (Operating System)

47, and a virtual machine manager (VMM) or hypervisor 46.

[0037] FIG. 5 shows an example of a Logical Unit table 50. The

Logical Volume table 50 includes columns of Logical Unit WWN (World Wide

Name) field 51 , Logical Unit number field 52, Storage Functionality field 55, and Destination LU type field 56. The Logical Unit WWN field 51 is for the identification name of Logical Unit 21 in the world wide unique name. The

Logical Unit number field 52 is for the identification number of Logical Unit 21 in the storage system. The Storage Functionality field 55 is for the storage function to be applied to the Logical Unit 21 . The Destination LU type field 56 is for identification name of Logical Unit 21 in the world wide unique name for a destination LU (i.e., target) of the storage functionality 55.

[0038] FIG. 6 shows an example of a host table 60. The host table 60 includes columns of host name field 61 , UUID (Universally Unique Identifier) field 62, host port ID field 63, hypervisor type field 64, and Guest OS type field 65. The host name field 61 contains the host server, virtual machine, or management host name. The UUID field 62 contains the UUID of the host. The host port ID field 63 contains identifiers of the host port(s) of the host server, virtual machine, or management host. The hypervisor type field 64 contains the type of the hypervisor of the host server, virtual machine, or management host. The Guest OS type field 65 contains the Guest OS type of the host server, virtual machine, or management host.

[0039] FIG. 7 shows an example of an operation table 70. The operation table 70 includes columns of operation ID field 71 and operation description field 72. The table is used to describe the relationship between a LU and a storage operation.

[0040] FIG. 8 shows an example of a LU relationship DB (Database) table 80. The LU relationship DB table 80 includes columns of index number field 81 , relationship type field 82, LU WWN field 83, host UUID field 84, Operation ID field 85, and timestamp field 86. The index number field 81 is for the task identifier. The relationship type field 82 is for the model of relationship type described above in connection with FIG. 2a (task to LU), FIG. 2b (LU to task), and FIG. 2c (task to task). The LU WWN field 83 is for identifying the LU using the LU WWN. The host UUID field 84 is for identifying the host using the host UUID. The Operation ID field 85 is for identifying the operation using the operation ID (see 71 in FIG. 7). The timestamp field 86 is operation time.

[0041] FIG. 9 shows diagrams of create LU, delete LU, or configuration changed LU operation relationship from the host server or management console. FIG. 9a shows that a storage task 22 is dependent on a logical unit 21 (task to LU). As an example, FIG. 9b shows that a create LU or delete LU task is dependent on a logical unit 21 x.

[0042] FIG. 10 shows diagrams of backup, snapshot, or replicate LU operation relationship from the host server or management console. FIG. 10a shows that a first logical unit 21 is dependent on a storage task 22 (LU to task) which is dependent on a second logical unit 21 (task to LU). As an example, FIG. 10b shows that a source logical unit 21 b is dependent on a copy task 80 (replicate, snapshot, or backup data from source LU to destination LU), which is dependent on a destination logical unit 21 x.

[0043] FIG. 1 1 shows a diagram of a repeated or cascading backup operation. A first logical unit 21 a is dependent on a first storage task 22w (backup operation such as writable snapshot) (LU to task) which is dependent on a second logical unit 21 b (task to LU), to back up data from the first logical unit 21 a to the second logical unit 21 b. The first logical unit 21 a is also dependent on a second storage task 22x (backup) (LU to task) which is dependent on a third logical unit 21 c (task to LU) which is dependent on a third storage task 22y (LU to task) which is dependent on a fourth logical unit 21 d (task to LU), to back up data from the first logical unit 21 a to the third logical unit 21 c and to back up data from the third logical unit 21 c to the fourth logical unit 21 d in a cascading manner.

[0044] FIG. 12 shows a diagram of a child operation relationship of a backup operation. A first storage task 22a (backup) is dependent on a second storage task 22b (create LU as the child operation of the backup operation) which is dependent on a first logical unit 21 a (destination LU), to create a destination LU for the backup operation. The backup task 22a is further dependent on a third storage task (replicate LU) 22c and a second logical unit (source LU) 21 b is also dependent on the replicate LU task 22c which is dependent on the destination LU, to replicate data from the source LU 21 b to the destination LU 21 a.

[0045] FIG. 13 shows an example of a flow diagram 1300 illustrating a storing operation task. In step S1301 , the storage system has received an operation task which involves LU creation, deletion, backup, restore, or the like. In step S1302, the storage program stores the operation task

relationship of the host, LU, and task type to the LU relationship database 80 (see FIG. 8).

[0046] FIG. 14 shows an example of a flow diagram 1400 illustrating a searching operation task. In step S1401 , the storage system has received a restore operation task whereby the server admin seeks to restore a LU from the backup LU. In step S1402, the storage program searches for a candidate backup LU which is dependent on the operated host ID from the LU graph based on the LU relationship database 80. In step S1403, the storage program returns the candidate backup LUs list.

[0047] FIG. 15 shows an example of a flow diagram 1500 illustrating a delete operation task. In step S1 501 , the storage system has received a delete operation task whereby the server admin seeks to delete a LU. In step

S1502, the storage program searches for related LUs that are dependent on the operated host ID from the LU graph based on the LU relationship database 80. In step S1503, the storage program notifies alert to the host or management client. The alert is sent, for example, when the operation affects some other host IO due to the operation by this host, such as a case in which the operation of one host affects the restore or backup operation of another host. For example, a recent UUID operation performed by one host may mean that the current UUIDs are mismatched in another operation to be performed. In this way, the server administrator can prevent mis-operation using the relationship information which includes alerts or messages when the operation involving one host affects the 10 of another host.

[0048] Of course, the system configuration illustrated in FIG. 1 is purely exemplary of information systems in which the present invention may be implemented, and the invention is not limited to a particular hardware configuration. The computers and storage systems implementing the invention can also have known I/O devices (e.g., CD and DVD drives, floppy disk drives, hard drives, etc.) which can store and read the modules, programs and data structures used to implement the above-described invention. These modules, programs and data structures can be encoded on such computer-readable media. For example, the data structures of the invention can be stored on computer-readable media independently of one or more computer-readable media on which reside the programs used in the invention. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include local area networks, wide area networks, e.g., the Internet, wireless networks, storage area networks, and the like.

[0049] In the description, numerous details are set forth for purposes of explanation in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that not all of these specific details are required in order to practice the present invention. It is also noted that the invention may be described as a process, which is usually depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged.

[0050] As is known in the art, the operations described above can be performed by hardware, software, or some combination of software and hardware. Various aspects of embodiments of the invention may be implemented using circuits and logic devices (hardware), while other aspects may be implemented using instructions stored on a machine-readable medium (software), which if executed by a processor, would cause the processor to perform a method to carry out embodiments of the invention.

Furthermore, some embodiments of the invention may be performed solely in hardware, whereas other embodiments may be performed solely in software.

Moreover, the various functions described can be performed in a single unit, or can be spread across a number of components in any number of ways.

When performed by software, the methods may be executed by a processor, such as a general purpose computer, based on instructions stored on a computer-readable medium. If desired, the instructions can be stored on the medium in a compressed and/or encrypted format.

[0051] From the foregoing, it will be apparent that the invention provides methods, apparatuses and programs stored on computer readable media for a storage system which stores and manages information for relationship between logical volumes and storage operations. Additionally, while specific embodiments have been illustrated and described in this specification, those of ordinary skill in the art appreciate that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments disclosed. This disclosure is intended to cover any and all adaptations or variations of the present invention, and it is to be

understood that the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with the established doctrines of claim interpretation, along with the full range of equivalents to which such claims are entitled.

Claims

WHAT IS CLAIMED IS:

1 . A storage system comprising:

a plurality of storage devices storing data; and

a controller being operable to manage a plurality of logical units on the plurality of storage devices, and having a memory to store information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation.

2. The storage system according to claim 1 ,

wherein the controller is operable, in response to an IO (Input/Output) request from a host computer, to use the stored information to identify one or more logical units involved in performing the IO request.

3. The storage system according to claim 2,

wherein the information includes information of the host computer.

4. The storage system according to claim 1 ,

wherein the operation is one of create a logical unit, delete a logical unit, replicate a logical unit, create backup of a logical unit, create snapshot of a logical unit, or restore a logical unit.

5. The storage system according to claim 1 , wherein the relationship type is one of (i) task to logical unit, (ii) logical unit to task, or (iii) task to task.

6. The storage system according to claim 5,

wherein the operation for task to logical unit relationship type is one of create a logical unit, delete a logical unit, replicate to a destination logical unit, create snapshot to a destination logical unit, create backup to a destination logical unit, or restore to a destination logical unit;

wherein the operation for logical unit to task relationship type is one of replicate from a source logical unit, create snapshot from a source logical unit, create backup from a source logical unit, or restore from a backup logical unit; and

wherein the operation for task to task relationship type is one of a backup operation task to a create backup logical unit task or a backup operation task to a replicate logical unit task.

7. The storage system according to claim 1 ,

wherein the controller is operable, in a restore operation to restore backup data from a backup logical unit to a destination logical unit, to find one or more candidate backup logical units of the plurality of logical units from which to restore backup data based on the stored information, and store a list of the one or more candidate backup logical units found.

8. The storage system according to claim 1 , wherein the controller is operable, in a delete operation to delete a logical unit, to find one or more candidate logical units of the plurality of logical units to delete based on the stored information, and to notify alert to one or more host computers when deleting the one or more candidate logical units will affect 10 (input/output) requests involving the one or more host computers based on the stored information.

9. A method of operating a storage system which includes a plurality of storage devices storing data, the method comprising:

managing a plurality of logical units on the plurality of storage devices; and

storing information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation.

10. The method according to claim 9, further comprising:

in response to an IO (Input/Output) request from a host computer, using the stored information to identify one or more logical units involved in performing the IO request.

1 1 . The method according to claim 1 0,

wherein the information includes information of the host computer.

12. The method according to claim 9, wherein the operation is one of create a logical unit, delete a logical unit, replicate a logical unit, create backup of a logical unit, create snapshot of a logical unit, or restore a logical unit.

13. The method according to claim 9,

wherein the relationship type is one of (i) task to logical unit, (ii) logical unit to task, or (iii) task to task.

14. The method according to claim 1 3,

15. A computer program for operating a storage system which includes a plurality of storage devices storing data, the computer program comprising: code for managing a plurality of logical units on the plurality of storage devices; and code for storing information indicating, for each logical unit to which an operation has been applied, the operation applied to the logical unit and a relationship type between the logical unit and the operation.

16. The computer program according to claim 15, further comprising:

code for, in response to an IO (Input/Output) request from a host computer, using the stored information to identify one or more logical units involved in performing the IO request.

17. The computer program according to claim 16,

wherein the information includes information of the host computer.

18. The computer program according to claim 15,

19. The computer program according to claim 15,

20. The computer program according to claim 19,