MANAGING STORAGE AND MIGRATION OF BACKUP DATA

• US 20090282203A1
• Filed: 05/09/2008
• Published: 11/12/2009
• Est. Priority Date: 05/09/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Haustein, Nils, Troppens, Ulf, Krick, Frank
• Granted Patent: US 8,090,917 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1461 Backup scheduling policy

Abstract

A method and system for client backup data management and storage using virtual tape libraries (VTLs). A VTL controller executing a software method receives metadata that distinguishes among a plurality of different versions of backup data. The VTL controller determines a latest version of the backup data. The VTL controller determines a migration set of zero or more versions of the backup data. The latest version and any version included in the migration set are included in the plurality of different versions. The VTL controller determines that a storage of the latest version in a first storage medium (e.g., magnetic disk) of the VTL is complete. The VTL controller migrates the migration set to a second storage medium (e.g., magnetic tape) of the VTL if the migration set includes at least one version of the backup data.

Claims

1. A computer-implemented method of managing storage and migration of backup data, said method comprising:

receiving, by a virtual tape library (VTL) controller included in a VTL, and via an execution of a first software method and in response to a receipt of a request from a client computing system for a backup of a set of data to generate backup data, metadata that distinguishes among a plurality of different versions of said backup data;

determining, by said VTL controller, a latest version of said backup data, wherein said latest version is included in said plurality of different versions of said backup data;

determining, by said VTL controller, a migration set of zero or more versions of said backup data, wherein any version of said backup data included in said migration set is included in said plurality of different versions of said backup data, and wherein said migration set is selected from the group consisting of a set of one or more versions of said backup data and an empty set including no version of said backup data;

determining, by said VTL controller and subsequent to said determining said latest version, that a storage of said latest version in a first storage medium of said VTL is complete; and

migrating, by said VTL controller and subsequent to said determining said migration set, said migration set to a second storage medium of said VTL if said migration set is said set of one or more versions of said backup data.

2. The method of claim 1, wherein said receiving said metadata includes receiving a client name, a backup type, and a timestamp included in said metadata, wherein said client name is an identifier of said client computing system, wherein said backup type is a type of said backup of said set of data, and wherein said timestamp includes a date and a time of said backup of said set of data.

3. The method of claim 2, wherein said migration set is said set of one or more versions of said backup data, and wherein said method further comprises:

identifying a first virtual tape identifier that identifies said first storage medium;

updating a record of a database table with said client name, said backup type, said timestamp and said first virtual tape identifier;

identifying a second virtual tape identifier that identifies said second storage medium; and

removing from said database table any record in which an identifier of a virtual tape matches said second virtual tape identifier.

4. The method of claim 2, wherein said migration set is said set of one or more versions of said backup data, and wherein said determining said migration set includes:

determining that said backup type is a full backup of said set of data;

selecting one or more records of a database table, wherein said one or more records include one or more identifiers of one or more virtual tapes of said VTL and one or more old timestamps, and each record of said one or more records includes said client name and any type of a backup of a version of said set of data, wherein each old timestamp indicates a time of a backup of a version of said set of data that occurred prior to said backup of said set of data; and

identifying said migration set as said one or more virtual tapes.

5. The method of claim 2, wherein said migration set is said set of one or more versions of said backup data, and wherein said determining said migration set includes:

determining that said backup type is a differential backup of said set of data;

selecting one or more records of a database table, wherein said one or more records include one or more identifiers of one or more virtual tapes of said VTL and one or more old timestamps, and each record of said one or more records includes said client name and a type of a backup that indicates an incremental backup, wherein each old timestamp indicates a time of a backup of a version of said set of data that occurred prior to said backup of said set of data; and

identifying said migration set as said one or more virtual tapes.

6. The method of claim 2, wherein said migration set is said empty set, and wherein said determining said migration set includes:

determining that said backup type is not a full backup of said set of data and is not a differential backup of said set of data;

selecting no records of one or more records of a database table, wherein a record of said one or more records includes said client name, a type of an old backup of a version of said set of data, an old timestamp that indicates a time of said old backup, and an identifier of a virtual tape of said VTL, wherein said old timestamp indicates a time of a backup of a version of said set of data that occurred prior to said backup of said set of data, and wherein said virtual tape stores said version of said set of data; and

determining that a migration of said version of said set of data to said second storage medium is not necessary.

7. The method of claim 2, further comprising:

identifying said backup type as a full backup of said set of data; and

mounting, in response to said identifying said backup type as said full backup, a new virtual tape in said VTL, wherein said new virtual tape stores no data from said plurality of different versions of said backup data.

8. The method of claim 2, further comprising:

identifying said backup type as a differential backup of said set of data;

determining that an amount of data stored in a first virtual tape in said VTL is less than a storage capacity of said first virtual tape, wherein said first virtual tape stores a most recent full backup version of said backup data, and wherein said most recent full backup version is included in said set of one or more versions of said backup data and is a result of a full backup; and

mounting, in response to said determining that said amount of data is less than said storage capacity, said first virtual tape.

9. The method of claim 2, further comprising:

identifying said backup type as a differential backup of said set of data;

determining that an amount of data stored in a first virtual tape in said VTL is greater than or equal to a storage capacity of said first virtual tape, wherein said first virtual tape stores a most recent full backup version of said backup data, and wherein said most recent full backup version is included in said set of one or more versions of said backup data and is a result of a full backup; and

mounting, in response to said determining that said amount of data is greater than or equal to said storage capacity, a new virtual tape in said VTL, wherein said new virtual tape stores no data from said plurality of different versions of said backup data.

10. The method of claim 2, further comprising:

identifying said backup type as an incremental backup of said set of data;

determining that an amount of data stored in a first virtual tape in said VTL is less than a storage capacity of said first virtual tape, wherein said first virtual tape stores a most recent full backup version of said backup data, wherein said most recent full backup version is included in said set of one or more versions of said backup data and is a result of a full backup; and

mounting, in response to said determining that said amount of data is less than said storage capacity, said first virtual tape.

11. The method of claim 2, further comprising:

identifying said backup type as an incremental backup of said set of data;

determining that an amount of data stored in a first virtual tape in said VTL is greater than or equal to a storage capacity of said first virtual tape, wherein said first virtual tape stores a most recent full backup version of said backup data, and wherein said most recent full backup version of said backup data is included in said set of one or more versions of said backup data and is a result of a full backup; and

mounting, in response to said determining that said amount of data is less than said storage capacity, a second virtual tape in said VTL, wherein said second virtual tape stores a most recent differential backup version of said backup data, and wherein said most recent differential backup version of said backup data is included in said set of one or more versions of said backup data and is a result of a differential backup.

12. The method of claim 2, further comprising:

identifying said backup type as an incremental backup of said set of data;

determining that an amount of data stored in a first virtual tape in said VTL is greater than or equal to a storage capacity of said first virtual tape, wherein said first virtual tape stores a most recent full backup version of said backup data, and wherein said most recent full backup version of said backup data is included in said set of one or more versions of said backup data and is a result of a full backup;

determining that an amount of data stored in a second virtual tape in said VTL is greater than or equal to a storage capacity of said second virtual tape, wherein said second virtual tape stores a most recent differential backup version of said backup data, and wherein said most recent differential backup version of said backup data is included in said set of one or more versions of said backup data and is a result of a differential backup; and

mounting, in response to said determining that said amount of data stored in said first virtual tape is greater than or equal to said storage capacity of said first virtual tape and in response to said determining that said amount of data stored in said second virtual tape is greater than or equal to said storage capacity of said second virtual tape, a new virtual tape in said VTL, wherein said new virtual tape stores no data from said plurality of different versions of said backup data.

13. The method of claim 1, wherein said receiving said metadata includes receiving said metadata from a backup server computing system executing a second software method that sends said metadata to said VTL controller via a storage area network.

14. The method of claim 1, wherein said receiving said metadata includes receiving said metadata from said client computing system via a storage area network.

15. The method of claim 1, wherein said method further comprises receiving, by said VTL controller, a Small Computer System Interface (SCSI) mode select command, and wherein said receiving said metadata includes receiving, subsequent to receiving said SCSI mode select command, a mode page that includes an identifier of said client computing system, an identifier of a type of said backup of said set of data, and a timestamp indicating a time of said backup of said set of data.

16. A computing system comprising a processor coupled to a computer-readable memory unit, said memory unit comprising a software application, said software application comprising instructions that when executed by said processor implement the method of claim 1.

17. A computer program product, comprising a computer-usable medium having a computer-readable program code embodied therein, said computer-readable program code comprising an algorithm adapted to implement the method of claim 1.

18. A process for supporting computing infrastructure, said process comprising providing at least one support service for at least one of creating, integrating, hosting, maintaining, and deploying computer-readable code in a second computing system, wherein the code in combination with the second computing system is capable of performing a method of managing storage and migration of backup data, said method comprising:

receiving, by a virtual tape library (VTL) controller included in a VTL, and via an execution of a first software method and in response to a receipt of a request from a client computing system for a backup of a set of data to generate backup data, metadata that distinguishes among a plurality of different versions of said backup data;

determining, by said VTL controller, a latest version of said backup data, wherein said latest version is included in said plurality of different versions of said backup data;

determining, by said VTL controller, a migration set of zero or more versions of said backup data, wherein any version of said backup data included in said migration set is included in said plurality of different versions of said backup data, and wherein said migration set is selected from the group consisting of a set of one or more versions of said backup data and an empty set including no version of said backup data;

determining, by said VTL controller and subsequent to said determining said latest version, that a storage of said latest version in a first storage medium of said VTL is complete; and

migrating, by said VTL controller and subsequent to said determining said migration set, said migration set to a second storage medium of said VTL if said migration set is said set of one or more versions of said backup data.

19. A computer-implemented method of managing storage and migration of backup data, said method comprising:

receiving, by a backup server, from a client computing system, and in response to a receipt of a request from said client computing system for a backup of a set of data to generate backup data, metadata that distinguishes among a plurality of different versions of said backup data, wherein said receiving said metadata includes receiving a client name, a backup type, and a timestamp included in said metadata, wherein said client name is an identifier of said client computing system, wherein said backup type is a type of said backup of said set of data, and wherein said timestamp includes a date and a time of said backup of said set of data;

determining, by said backup server, a latest version of said backup data, wherein said latest version is included in said plurality of different versions of said backup data;

identifying a first virtual tape of a virtual tape library (VTL), wherein said identifying said first virtual tape includes identifying said backup type included in said metadata;

mounting said first virtual tape by said backup server;

determining, by said backup server and based on said backup type, a migration set of zero or more versions of said backup data, wherein any version of said backup data included in said migration set is included in said plurality of different versions of said backup data, and wherein said migration set is selected from the group consisting of a set of one or more versions of said backup data and an empty set including no version of said backup data;

determining, by said backup server and subsequent to said determining said latest version, that a storage of said latest version in a first storage medium of said VTL is complete;

instructing, by said backup server, said VTL to perform a migration of said migration set to a second storage medium of said VTL;

determining, by said backup server, that said migration of said migration set to said second storage medium is complete;

identifying, by said backup server, a first virtual tape identifier that identifies said first storage medium;

updating, by said backup server, a record of a database table with said client name, said backup type, said timestamp and said first virtual tape identifier;

identifying, by said backup server, a second virtual tape identifier that identifies said second storage medium; and

removing, from said database table and by said backup server, any record in which an identifier of a virtual tape matches said second virtual tape identifier.

20. The method of claim 19, wherein said instructing said VTL to perform a migration of said migration set to said second storage medium includes:

sending, by said backup server to said VTL, a modification of a Small Computer System Interface (SCSI) position to element command that includes a command code, a logical unit number, a transport element address, a destination element address, and a migrate field, wherein said logical unit number is a SCSI address of said VTL, and wherein said destination element address specifies an element address of a second virtual tape that includes a version of said backup data included in said migration set;

identifying a predefined migration indicator stored in said migrate field; and

migrating, in response to identifying said predefined migration indicator, said second virtual tape to said second storage medium.