Safety for volume operations

• US 9,436,720 B2
• Filed: 10/04/2013
• Issued: 09/06/2016
• Est. Priority Date: 01/10/2013
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Colgrove, John, Miller, Ethan, Hayes, John, Sandvig, Cary, Golden, Christopher, Cao, Jianting
• Primary Examiner(s): Sun, Scott
• Application Number:
  US14/046,878
• Publication Number:
  US 20140195762A1
• Time in Patent Office: 1,068 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: G06F 16/23 Updating
• CPC Class Codes: G06F 2212/1008 Correctness of operation, e.g. memory ordering
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/1032 Reliability improvement, data loss prevention, degraded operation etc
• CPC Class Codes: G06F 2212/1044 Space efficiency improvement
• CPC Class Codes: G06F 2212/154 Networked environment
• CPC Class Codes: G06F 2212/163 Server or database system
• CPC Class Codes: G06F 2212/261 Storage comprising a plurality of storage devices
• CPC Class Codes: G06F 2212/263 Network storage, e.g. SAN or NAS
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0614 Improving the reliability of storage systems
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/0644 : Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/065 : Replication mechanisms
• CPC Class Codes: G06F 3/0652 : Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0655 : Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0664 : at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0665 : at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0667 : at data level, e.g. file, record or object virtualisation
• CPC Class Codes: G06F 3/067 : Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0671 : In-line storage system
• CPC Class Codes: G06F 3/0673 : Single storage device
• CPC Class Codes: G06F 3/0683 : Plurality of storage devices
• CPC Class Codes: G06F 3/0685 : Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 3/0689 : Disk arrays, e.g. RAID, JBOD

Abstract

A system and method for maintaining the safety of volume operations. A storage controller receives a request to delete a first volume. In response to this request, the storage controller can delete a link between the first volume and its anchor medium. The storage controller can also delay the deletion of the first volume'"'"'s anchor medium. Later on, if the user wishes to restore the first volume, the storage controller can reconnect the first volume to its previous anchor medium, effectively restoring the first volume to its former state and undoing the deletion operation.

Claims

1. A computer system comprising:

one or more storage devices; and

a storage controller coupled to the one or more storage devices, wherein the storage controller is configured to;

receive a request to delete a first volume mapped to a first medium, wherein the first medium is a logical grouping of data;

responsive to receiving the request to delete the first volume;

determine the first medium is an anchor medium of the first volume;

store an indication that the first volume was previously linked to the first medium; and

remove any indication that the first volume is valid.

2. The computer system as recited in claim 1, wherein the storage controller is further configured to maintain a volume to medium mapping table to track relationships between volumes and anchor mediums, and wherein removing any indication that the first volume is valid comprises deleting a first entry corresponding to the first volume from the volume to medium mapping table.

3. The computer system as recited in claim 2, wherein after receiving the request to delete the first volume, the storage controller is further configured to:

receive a request to restore the first volume;

responsive to receiving the request to restore the first volume;

retrieve the indication that the first volume was previously linked to the first medium; and

create a new entry in the volume to medium mapping table, wherein the new entry links the first volume to the first medium.

4. The computer system as recited in claim 2, wherein after receiving the request to delete the first volume, the storage controller is configured to:

receive a request to restore the first volume;

responsive to receiving the request to restore the first volume;

retrieve the indication that the first volume was previously linked to the first medium;

create a second medium;

store an indication that the first medium underlies the second medium; and

create a new entry in the volume to medium mapping table, wherein the new entry links the first volume to the second medium.

5. The computer system as recited in claim 1, wherein responsive to receiving the request to delete the first volume, the storage controller is further configured to delay deletion of the first medium for a first period of time.

6. The computer system as recited in claim 5, wherein after the first period of time has elapsed, the storage controller is configured to mark the first medium as ready to be reclaimed.

7. The computer system as recited in claim 6, wherein after the first period of time has elapsed, the storage controller is further configured to mark a second medium as ready to be reclaimed if the second medium underlies the first medium and if no other mediums are linked to the second medium.

8. A method for use in a storage system, the method comprising:

receiving a request to delete a first volume mapped to a first medium, wherein the first medium is a logical grouping of data;

responsive to receiving the request to delete the first volume;

determining the first medium is an anchor medium of the first volume;

storing an indication that the first volume was previously linked to the first medium; and

removing any indication that the first volume is valid.

9. The method as recited in claim 8, further comprising maintaining a volume to medium mapping table to track relationships between volumes and anchor mediums, and wherein removing any indication that the first volume is valid comprises deleting a first entry corresponding to the first volume from the volume to medium mapping table.

10. The method as recited in claim 9, wherein after receiving the request to delete the first volume, the method further comprising:

receiving a request to restore the first volume;

responsive to receiving the request to restore the first volume;

retrieving the indication that the first volume was previously linked to the first medium; and

creating a new entry in the volume to medium mapping table, wherein the new entry links the first volume to the first medium.

11. The method as recited in claim 9, wherein after receiving the request to delete the first volume, the method further comprising:

receiving a request to restore the first volume;

responsive to receiving the request to restore the first volume;

retrieving the indication that the first volume was previously linked to the first medium;

creating a second medium;

storing an indication that the first medium underlies the second medium; and

creating a new entry in the volume to medium mapping table, wherein the new entry links the first volume to the second medium.

12. The method as recited in claim 8, wherein responsive to receiving the request to delete the first volume, the method further comprising delaying deletion of the first medium for a first period of time.

13. The method as recited in claim 12, wherein after the first period of time has elapsed, the method comprising marking the first medium as ready to be reclaimed.

14. The method as recited in claim 13, wherein after the first period of time has elapsed, the method further comprising marking a second medium as ready to be reclaimed if the second medium underlies the first medium and if no other mediums are linked to the second medium.

15. A non-transitory computer readable storage medium storing program instructions, wherein the program instructions are executable by a processor to:

receive a request to delete a first volume mapped to a first medium, wherein the first medium is a logical grouping of data;

responsive to receiving the request to delete the first volume;

determine the first medium is an anchor medium of the first volume;

store an indication that the first volume was previously linked to the first medium; and

remove any indication that the first volume is valid.

16. The computer readable storage medium as recited in claim 15, wherein the program instructions are further executable by a processor to maintain a volume to medium mapping table to track relationships between volumes and anchor mediums, and wherein removing any indication that the first volume is valid comprises deleting a first entry corresponding to the first volume from the volume to medium mapping table.

17. The computer readable storage medium as recited in claim 16, wherein after receiving the request to delete the first volume, the program instructions are further executable by a processor to:

receive a request to restore the first volume;

responsive to receiving the request to restore the first volume;

retrieve the indication that the first volume was previously linked to the first medium; and

create a new entry in the volume to medium mapping table, wherein the new entry links the first volume to the first medium.

18. The computer readable storage medium as recited in claim 16, wherein after receiving the request to delete the first volume, the program instructions are further executable by a processor to:

receive a request to restore the first volume;

responsive to receiving the request to restore the first volume;

retrieve the indication that the first volume was previously linked to the first medium;

create a second medium;

store an indication that the first medium underlies the second medium; and

create a new entry in the volume to medium mapping table, wherein the new entry links the first volume to the second medium.

19. The computer readable storage medium as recited in claim 15, wherein responsive to receiving the request to delete the first volume, the program instructions are further executable by a processor to delay deletion of the first medium for a first period of time.

20. The computer readable storage medium as recited in claim 19, wherein after the first period of time has elapsed, the program instructions are executable by a processor to mark the first medium as ready to be reclaimed.