System and method for restriping data across a plurality of volumes

• US 8,578,090 B1
• Filed: 05/18/2007
• Issued: 11/05/2013
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Jernigan, Richard P. IV
• Primary Examiner(s): PATEL, KAUSHIKKUMAR M
• Application Number:
  US11/750,775
• Time in Patent Office: 2,363 Days
• Field of Search: None
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1096 Parity calculation or recalculation after configuration or reconfiguration of the system
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A system and method re-stripes one or more data containers across a striped volume set (SVS) that has been modified by the addition of one or more volumes. The SVS is associated with an existing set of striping rules that define a stripe algorithm, a stripe width and an ordered list of volumes distributed across a plurality of nodes interconnected as a cluster. Each node of the cluster includes (i) a disk element (D-blade) adapted to service a volume of the SVS and (ii) a network element (N-blade) adapted to redirect a data access request to any D-blade of the cluster. Notably, the content of each data container is apportioned among the volumes of the SVS to thereby improve the efficiency of storage service provided by the cluster. To that end, the stripe algorithm specifies the manner in which the data container content is apportioned as stripes across the plurality of volumes, while the stripe width specifies the size/width of each stripe.

Claims

1. A method for restriping data across a striped volume set, comprising:

receiving a command directed to a data container striped across each volume of a plurality of volumes of the striped volume set, wherein each volume includes one or more Redundant Array of Independent Disks (RAID) groups;

determining which volume of the plurality of volumes of the striped volume set stores a stripe associated with the received command by selecting a striping rule of a plurality of striping rules associated with the striped volume set by in response to analyzing a striped volume set identifier in a file handle associated with the received command, wherein the striping rule defines a striping algorithm that specifies a manner in which data of the data container is apportioned as stripes across the plurality of volumes of the striped volume set; and

forwarding the received command to a computer having a processor and serving the volume, of the striped volume set, storing the stripe associated with the command.

2. The method of claim 1 wherein each of the plurality of striping rules comprises a generation value floor that identifies which inodes are associated with each of the plurality of striping rules.

3. The method of claim 1 further comprising:

adding a volume to the striped volume set;

creating a new data container; and

striping the new data container across the striped volume set including the added volume utilizing a new striping rule.

4. The method of claim 1 further comprising using a first striping rule for a first data container of the striped volume set and using a second striping rule for a second data container of the striped volume set.

5. The method of claim 1 wherein the data container is a file.

6. The method of claim 1 wherein the computer is a D-blade.

7. A system for restriping data across a striped volume set, comprising:

one or more storage systems having a processor and a striping module configured to process a command directed to a data container striped across each volume of a plurality of volumes of the striped volume set, wherein each volume includes one or more Redundant Array of Independent Disks (RAID) groups; and

one or more storage operating systems of the one or more storage systems configured to select a striping rule of a plurality of striping rules associated with the striped volume set in response to analyzing a striped volume set identifier in a file handle associated with the received command, to determine which volume of the striped volume set stores a stripe associated with the command, wherein the striping rule defines a striping algorithm that specifies a manner in which data of the data container is apportioned as stripes across the plurality of volumes of the striped volume set, the storage operating system further configured to forward the command to a storage system serving the volume, of the striped volume set, storing the stripe associated with the command.

10. The system of claim 7 wherein at least one storage operating system of the one or more storage operating systems comprises a multi-protocol engine.

11. The system of claim 10 further comprising:

the striped volume set configured to add a volume to the striped volume set;

the striped volume set further configured to store a new data container; and

the striped volume set further configured to stripe the new data container across the striped volume set including the added volume utilizing a new striping rule.

12. The system of claim 10 further comprising one or more processors configured to use a first striping rule for a first data container of the striped volume set and further configured to use a second striping rule for a second data container of the striped volume set.

13. The system of claim 10 wherein the data container is a file.

14. The system of claim 10 wherein the computer is a D-blade.

15. The system of claim 10 wherein the at least one storage operating system of the one or more storage operating systems comprises a cluster fabric interface module configured to select the striping rule of the plurality of striping rules of the striped volume set.

8. A computer system for restriping data across a striped volume set, comprising:

a processor of the computer system configured to execute a storage operating system to perform storage operations of the striped volume set;

means for receiving a command directed to a data container striped across each volume of a plurality of volumes of the striped volume set, wherein each volume includes one or more Redundant Array of Independent Disks (RAID) groups;

means for determining which volume of the plurality of volumes of the striped volume set stores a stripe associated with the received command by selecting a striping rule of a plurality of striping rules associated with the striped volume set in response to analyzing a striped volume set identifier in a file handle associated with the received command, wherein the striping rule defines a striping algorithm that specifies a manner in which data of the data container is apportioned as stripes across the plurality of volumes of the striped volume set; and

means for forwarding the received command to a computer serving the volume, of the striped volume set, storing the stripe associated with the command.

9. A non-transitory computer readable medium containing executable program instructions executed by a processor, comprising:

program instructions that receive a command directed to a data container striped across each volume of a plurality of volumes of a striped volume set, wherein each volume includes one or more Redundant Array of Independent Disks (RAID) groups;

program instructions that determine which volume of the plurality of volumes of the striped volume set stores a stripe associated with the received command by selecting a striping rule of a plurality of striping rules associated with the striped volume set in response to analyzing a striped volume set identifier in a file handle associated with the received command, wherein the striping rule defines a striping algorithm that specifies a manner in which data of the data container is apportioned as stripes across the plurality of volumes of the striped volume set; and

program instructions that forward the received command to a computer serving the volume, of the striped volume set, storing the stripe associated with the command.