Validation of storage arrays based on information stored in global metadata

• US 10,108,362 B2
• Filed: 09/29/2015
• Issued: 10/23/2018
• Est. Priority Date: 10/18/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Grusy, Ellen J., Lovrien, Kurt A., Nielsen, Karl A., Sheppard, Jacob L.
• Primary Examiner(s): Rahman, Fahmida
• Application Number:
  US14/869,844
• Publication Number:
  US 20160019003A1
• Time in Patent Office: 1,120 Days
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• 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 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A director node of a plurality of nodes determines a plurality of data arrays, where the plurality of data arrays have been discovered at boot time. The director node determines global metadata information, based on reading boot sectors of at least one of the plurality of data arrays discovered at boot time. A determination is made from the global metadata information as to how many data arrays had been previously configured. In response to determining that the plurality of data arrays discovered at boot time is not equal in number to the previously configured data arrays, the director node determines that all configured data arrays have not been discovered.

Claims

1. A method, comprising:

maintaining, via a processor, a current set of three global metadata arrays, wherein a boot sector in each of the three global metadata arrays stores pointer records pointing to the current set of the three global metadata arrays, wherein each of the three global metadata arrays stores global metadata information including a number of previously configured data arrays;

determining, by a director node, based on reading boot sectors of at least one of a plurality of data arrays discovered at boot time, the global metadata information that stores the number of previously configured data arrays; and

in response to determining that the plurality of data arrays discovered by the director node at the boot time is not equal in number to the number of previously configured data arrays, determining that all configured data arrays have not been discovered;

transmitting an error condition, in response to determining that all configured data arrays have not been discovered, wherein one or more of the configured data arrays that have not been discovered have a currently valid global metadata information; and

configuring a computing system, in response to determining that the plurality of data arrays discovered by the director node at the boot time is equal in number to the number of previously configured data arrays and all configured data arrays have been discovered.

2. The method of claim 1, wherein boot sectors of other data arrays besides the global metadata arrays do not store pointer records pointing to the current set of global metadata arrays.

3. The method of claim 2, wherein the three metadata arrays comprise a primary, a secondary, and a tertiary data array.

4. The method of claim 3, wherein the director node synchronizes the global metadata information among the primary, the secondary, and the tertiary data arrays.

5. The method of claim 1, wherein the director node configures components of a computing environment based on the global metadata information.

6. The method of claim 1, wherein a pointer record to global metadata arrays includes serial number indicators of data arrays.

7. A system in communication with a plurality of nodes, the system comprising:

a memory; and

a processor coupled to the memory, wherein the processor performs operations, the operations comprising;

maintaining a current set of three global metadata arrays, wherein a boot sector in each of the three global metadata arrays stores pointer records pointing to the current set of the three global metadata arrays, wherein each of the three global metadata arrays stores global metadata information including a number of previously configured data arrays;

determining, based on reading boot sectors of at least one of a plurality of data arrays discovered at boot time, the global metadata information that stores the number of previously configured data arrays; and

in response to determining that the plurality of data arrays discovered at the boot time is not equal in number to the number of previously configured data arrays, determining that all configured data arrays have not been discovered;

transmitting an error condition, in response to determining that all configured data arrays have not been discovered, wherein one or more of the configured data arrays that have not been discovered have a currently valid global metadata information; and

configuring a computing system, in response to determining that the plurality of data arrays discovered by the director node at the boot time is equal in number to the number of previously configured data arrays and all configured data arrays have been discovered.

8. The system of claim 7, wherein boot sectors of other data arrays besides the global metadata arrays do not store pointer records pointing to the current set of global metadata arrays.

9. The system of claim 8, wherein the three metadata arrays comprise a primary, a secondary, and a tertiary data array.

10. The system of claim 9, wherein the operations further comprise synchronizing the global metadata information among the primary, the secondary, and the tertiary data arrays.

11. The system of claim 7, wherein the director node configures components of a computing environment based on the global metadata information.

12. The system of claim 7, wherein a pointer record to global metadata arrays includes serial number indicators of data arrays.

13. A computer program product, the computer program product comprising a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to perform operations, the operations comprising:

maintaining, via a processor, a current set of three global metadata arrays, wherein a boot sector in each of the three global metadata arrays stores pointer records pointing to the current set of the three global metadata arrays, wherein each of the three global metadata arrays stores global metadata information including a number of previously configured data arrays;

determining, by a director node, based on reading boot sectors of at least one of a plurality of data arrays discovered at boot time, the global metadata information that stores the number of previously configured data arrays; and

in response to determining that the plurality of data arrays discovered by the director node at the boot time is not equal in number to the number of previously configured data arrays, determining that all configured data arrays have not been discovered;

transmitting an error condition, in response to determining that all configured data arrays have not been discovered, wherein one or more of the configured data arrays that have not been discovered have a currently valid global metadata information; and

configuring a computing system, in response to determining that the plurality of data arrays discovered by the director node at the boot time is equal in number to the number of previously configured data arrays and all configured data arrays have been discovered.

14. The computer program product of claim 13, wherein boot sectors of other data arrays besides the global metadata arrays do not store pointer records pointing to the current set of global metadata arrays.

15. The computer program product of claim 14, wherein the three metadata arrays comprise a primary, a secondary, and a tertiary data array.

16. The computer program product of claim 15, wherein the director node synchronizes the global metadata information among the primary, the secondary, and the tertiary data arrays.

17. The computer program product of claim 13, wherein the director node configures components of a computing environment based on the global metadata information.

18. The computer program product of claim 13, wherein a pointer record to global metadata arrays includes serial number indicators of data arrays.