AUTOMATIC REDUNDANT LOGICAL CONNECTIONS

• US 20120120791A1
• Filed: 10/26/2009
• Published: 05/17/2012
• Est. Priority Date: 08/28/2009
• Status: Active Grant

• Current Assignee: Micro Focus LLC (Open Text Corporation)
• Original Assignee: entIT Software LLC (Open Text Corporation)
• Inventors: Ananda Ganesan, Senthil-Kumar, Sagi, Vasavi, Padmanabha, Anuradha Anantha
• Granted Patent: US 9,774,675 B2
• Time in Patent Office: Days
• US Class Current: 370/225
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04W 28/04 Error control

Abstract

A method (600) includes: providing (602) a physical connection topology and a logical connection topology between a host (302) and a logical unit hosted on a storage array (308), the topologies including all network fabrics to which both the host (302) and the storage array (308) belong; determining (604) at least one single point of failure is located between the host (302) and the logical unit within a particular network fabric; attempting (606) to create a fully redundant logical connection between the host (302) and the logical unit within the particular fabric; if a fully redundant logical connection is not possible in the particular fabric, attempting (608) to create a fully redundant logical connection between the host (302) and the logical unit using an alternate fabric; and if a fully redundant logical connection is not possible in the topologies, attempting (610) to create a partially redundant logical connection between the host (302) and the logical unit within the particular network fabric.

Claims

1. A method (600) for creating redundant logical connections, comprising:

providing (602) a physical connection topology and a logical connection topology between a host (302) and a logical unit hosted on a storage array (308), said physical connection topology and said logical connection topology comprising all network fabrics to which both said host (302) and said storage array (308) belong;

determining (604) at least one single point of failure is located between said host (302) and said logical unit within a particular network fabric;

attempting (606) to create a fully redundant logical connection between said host (302) and said logical unit within said particular network fabric;

if a fully redundant logical connection is not possible in said particular network fabric, attempting (608) to create a fully redundant logical connection between said host (302) and said logical unit using an alternate of said network fabrics; and

if a fully redundant logical connection is not possible in any alternate network fabric in said topologies, attempting (610) to create a partially redundant logical connection between said host (302) and said logical unit within said particular network fabric.

2. The method (600) of claim 1, in which said method (600) is performed proactively before encountering a failure at a single point of failure.

3. The method (600) of claim 1, in which said method (600) is performed reactively after encountering a single point of failure.

4. The method (600) of claim 1, in which said method (600) is performed for every host (302) and logical unit having a logical connection that is impacted by said failure.

5. The method (600) of claim 1, in which said fully redundant logical connection comprises:

redundant logical links (318) between a host bus adapter port (310) of said host (302) and a switch port (312);

redundant logical links (318) between said switch port (312) and any other switch ports (312) through inter switch links (316); and

redundant logical links (318) between said switch port (312) and a controller port (314) on said storage array (308), said logical unit being mapped on said controller port (314).

6. The method (600) of claim 1, in which said fully redundant logical connection comprises:

redundant logical links (318) between a host bus adapter port (310) of said host (302) and a switch port (312); and

redundant logical links (318) between said switch port (312) and a controller port (314) on said storage array (308), said logical unit being mapped on said controller port (314),

in which redundant logical links (318) between said switch port (312) and any other switch ports (312) using inter switch links (316) are automatically taken care of as part of a functionality of said network fabric.

7. The method (600) of claim 1, further comprising creating a redundant logical link (318) at said single point of failure if said redundant logical link (318) is possible.

8. A storage automation system connecting a host (302) with a logical unit, comprising:

a physical connection topology and a logical connection topology between said host (302) and said logical unit hosted on a storage array (308), said physical connection topology and said logical connection topology comprising all network fabrics to which both said host (302) and said storage array (308) belong;

at least one switch (304) located in said physical connection topology between said host (302) and said logical unit; and

at least one logical connection through said physical connection topology between said host (302) and said logical unit;

in which said system is configured to automatically establish a redundant logical connection between said host (302) and said logical unit upon discovery of a single point of failure in said at least one logical connection.

9. The system of claim 8, in which said redundant logical connection is a fully redundant logical connection between said host (302) and said logical unit, said fully redundant logical connection comprising redundant logical links (318) between each component of said system.

10. The system of claim 8, in which said redundant logical connection is a partially redundant logical connection between said host (302) and said logical unit, in which said partially redundant logical connection comprises redundant logical links (318) between two components of said system within said particular network fabric.

11. A computer readable storage medium having stored thereon instructions for causing a processor to execute a method for automatically creating redundant logical connections in a network, said method (600) comprising:

determining (604) where a single point of failure is located between a host (302) and a logical unit hosted on a storage array (308) in a particular network fabric having a given physical and logical connection topology comprising all network fabrics to which both said host (302) and said storage array (308) belong,

attempting (606) to create a fully redundant logical connection between said host (302) and said logical unit within said particular network fabric;

if a fully redundant logical connection is not possible within said particular network fabric, attempting (608) to create a fully redundant logical connection between said host (302) and said logical unit using an alternate of said network fabrics; and

if a fully redundant logical connection is not possible in any alternate network fabric in said topologies, attempting (610) to create a partially redundant logical connection between said host (302) and said logical unit within said particular network fabric.

12. The computer readable storage medium of claim 11, in which said fully redundant logical connection comprises:

redundant logical links (318) between a host bus adapter port (310) of said host (302) and a switch port (312);

redundant logical links (318) between said switch port (312) and any other switch ports (312) physically connected using inter switch links (316); and

redundant logical links (318) between said switch port (312) and a controller port (314) on said storage array (308), said logical unit being mapped on said controller port (314).

13. The computer readable storage medium of claim 11, in which said fully redundant logical connection comprises:

redundant logical links (318) between a host bus adapter port (310) of said host (302) and a switch port (312); and

redundant logical links (318) between said switch port (312) and a controller port (314) on said storage array (308), said logical unit being mapped on said controller port (314),

in which redundant logical links (318) between said switch port (312) and any other switch ports (312) using inter switch links (316) are automatically taken care of as part of a functionality of said network fabric.

14. The computer readable storage medium of claim 11, in which said method (600) is applied to every host (302) and each of its logical units.

15. The computer readable storage medium of claim 11, in which said method (600) is applied to every host (302) and logical unit having a logical connection that is impacted by a failure.