Replication and intermediate read-write state for mediums

• US 9,817,608 B1
• Filed: 11/11/2015
• Issued: 11/14/2017
• Est. Priority Date: 06/25/2014
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Golden, Christopher, Cao, Jianting, Grunwald, David, Sharpe, Malcolm, Hodgson, Steve
• Primary Examiner(s): Mackes, Kris
• Assistant Examiner(s): Bui, Tiffany
• Application Number:
  US14/938,243
• Time in Patent Office: 734 Days
• Field of Search: 707634
• CPC Class Codes: G06F 11/1658 Data re-synchronization of a redundant component, or initial sync of replacement, additional or spare unit
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 3/06 Digital input from, or digital output to, record carriers , e.g. RAID, emulated record carriers or networked record carriers
• CPC Class Codes: G06F 3/061 Improving I/O performance
• 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 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• 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 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A system and method for exposing volumes with underlying read-write mediums to user operations. When a medium is in the process of being replicated to a storage array, a volume which relies on the medium can be exposed to user operations (e.g., snapshots, read and write operations) once the portions of the medium which underlie the volume have been replicated. The volume can be exposed to user operations while one or more other portions of the medium are unfilled and while the medium is in an intermediate read-write state.

Claims

1. A method comprising:

by computer program instructions on one or more computing devices;

detecting a request to replicate a first volume from a first storage array to a second storage array;

in response to the detecting the request, identifying a plurality of logical groupings of stored data that include a logical portion that underlies the first volume, wherein at least one of the plurality of logical groupings of stored data includes a logical portion that does not underlie the first volume;

in each of the identified logical groupings of stored data, replicating the logical portion that underlies the first volume;

determining for each of the identified logical groupings of stored data, whether the logical portion that underlies the first volume is replicated on the second storage array; and

in response to determining for each of the identified logical groupings of stored data that the logical portion that underlies the first volume is replicated on the second storage array, exposing to user operations the first volume on the second storage array before the logical portion that does not underlie the first volume is replicated on the second storage array.

2. The method of claim 1 further comprising:

by the computer program instructions on the one or more computing devices;

retrieving one or more mappings associated with the first volume, wherein each mapping associates the first volume with a particular logical grouping of stored data that underlies the first volume.

3. The method of claim 1 further comprising by the computer program instructions on the one or more computing devices:

selecting, for replication, in each of the identified logical groupings of stored data, the logical portion that underlies the first volume.

4. The method of claim 1 further comprising:

by the computer program instructions on the one or more computing devices;

for each of the identified logical groupings of stored data;

determining whether all logical portions of the logical grouping of stored data have been replicated; and

responsive to determining that all logical portions of the logical grouping of stored data have been replicated, placing the logical grouping of stored data in a read-only state.

5. An apparatus comprising a computer processor and a computer memory operatively coupled to the computer processor, the computer memory having disposed within it computer program instructions that, when executed by the computer processor, cause the computer processor to carry out the steps of:

detecting a request to replicate a first volume from a first storage array to a second storage array;

in response to the detecting the request, identifying a plurality of logical groupings of stored data that include a logical portion that underlies the first volume, wherein at least one of the plurality of logical groupings of stored data includes a logical portion that does not underlie the first volume;

in each of the identified logical groupings of stored data, replicating the logical portion that underlies the first volume;

determining for each of the identified logical groupings of stored data, whether the logical portion that underlies the first volume is replicated on the second storage array; and

in response to determining for each of the identified logical groupings of stored data that the logical portion that underlies the first volume is replicated on the second storage array, exposing to user operations the first volume on the second storage array before the logical portion that does not underlie the first volume is replicated on the second storage array.

6. The apparatus of claim 5 further comprising computer program instructions that, when executed by the computer processor, cause the computer processor to carry out the steps of:

retrieving one or more mappings associated with the first volume, wherein each mapping associates the first volume with a particular logical grouping of stored data that underlies the first volume.

7. The apparatus of claim 5 further comprising computer program instructions that, when executed by the computer processor, cause the computer processor to carry out the step of selecting, for replication, in each of the identified logical groupings of stored data, the logical portion that underlies the first volume.

8. The apparatus of claim 5 further comprising computer program instructions that, when executed by the computer processor, cause the computer processor to carry out the steps of:

for each of the identified logical groupings of stored data;

determining whether all logical portions of the logical grouping of stored data have been replicated; and

responsive to determining that all logical portions of the logical grouping of stored data have been replicated, placing the logical grouping of stored data in a read-only state.

9. A computer program product, the computer program product disposed upon a non-transitory computer readable medium, the computer program product comprising computer program instructions that, when executed, cause a computer to carry out the steps of:

detecting a request to replicate a first volume from a first storage array to a second storage array;

in response to the detecting the request, identifying a plurality of logical groupings of stored data that include a logical portion that underlies the first volume, wherein at least one of the plurality of logical groupings of stored data includes a logical portion that does not underlie the first volume;

in each of the identified logical groupings of stored data, replicating the logical portion that underlies the first volume;

determining for each of the identified logical groupings of stored data, whether the logical portion that underlies the first volume is replicated on the second storage array; and

in response to determining for each of the identified logical groupings of stored data that the logical portion that underlies the first volume is replicated on the second storage array, exposing to user operations the first volume on the second storage array before the logical portion that does not underlie the first volume is replicated on the second storage array.

10. The computer program product of claim 9 further comprising computer program instructions that, when executed, cause the computer to carry out the steps of:

retrieving one or more mappings associated with the first volume, wherein each mapping associates the first volume with a particular logical grouping of stored data that underlies the first volume.

11. The computer program product of claim 9 further comprising computer program instructions that, when executed, cause the computer to carry out the step of selecting, for replication, in each of the identified logical groupings of stored data, the logical portion that underlies the first volume.

12. The computer program product of claim 9 further comprising computer program instructions that, when executed, cause the computer to carry out the steps of:

for each of the identified logical groupings of stored data;

determining whether all logical portions of the logical grouping of stored data have been replicated; and

responsive to determining that all logical portions of the logical grouping of stored data have been replicated, placing the logical grouping of stored data in a read-only state.