Concurrency control in a file system shared by application hosts
First Claim
1. A method, comprising:
- sharing a plurality of logical units in a data storage system among a plurality of hosts, wherein the plurality of logical units are available to be formatted with a file system associated with any of the plurality of hosts to form a logical data storage entity for one of the plurality of hosts, the logical data storage entity including a set of logical units from the plurality of logical units that have been formatted with the file system;
receiving a notification message from a first host indicating an occurrence of an event corresponding to a logical unit of the data storage system, wherein the event relates to use of the logical unit in relation to a logical data storage entity associated with the first host that is identified by a data storage entity identifier and associated with a file system, wherein the logical unit is part of the logical data storage entity and is associated with the file system of the logical data storage entity;
determining whether a second host having access to the data storage system also shares access to the logical unit with the first host; and
sending, by a computing device, a refresh message to the second host that causes the second host to update information relating to the logical data storage entity associated with the first host that includes the logical unit in a cache of the second host to reflect the occurrence of the event, wherein the data storage entity identifier associated with the data storage entity is identified as including the logical unit in the cache to indicate the logical unit is formatted by the file system of the logical data storage entity thereby preventing the second host from performing a second event corresponding to the logical unit that is inconsistent with the event.
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Accused Products
Abstract
A manager program for managing virtual machines includes a process which receives a notification message indicating an occurrence of an event affecting a data storage unit in a data storage system that supports a shared file system. The notification message might have come from a virtual machine host or resulted from a hardware reconfiguration. The manager program then determines whether another virtual machine host is sharing the data storage unit. The manager program might make this determination by polling each of the virtual machine hosts it manages or by checking information previously collected and stored in a database. If another virtual machine host is sharing the data storage unit, the manager program sends a refresh message to that virtual machine host that causes the virtual machine host to update information relating to the data storage unit in a cache associated with the virtual machine host.
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Citations
21 Claims
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1. A method, comprising:
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sharing a plurality of logical units in a data storage system among a plurality of hosts, wherein the plurality of logical units are available to be formatted with a file system associated with any of the plurality of hosts to form a logical data storage entity for one of the plurality of hosts, the logical data storage entity including a set of logical units from the plurality of logical units that have been formatted with the file system; receiving a notification message from a first host indicating an occurrence of an event corresponding to a logical unit of the data storage system, wherein the event relates to use of the logical unit in relation to a logical data storage entity associated with the first host that is identified by a data storage entity identifier and associated with a file system, wherein the logical unit is part of the logical data storage entity and is associated with the file system of the logical data storage entity; determining whether a second host having access to the data storage system also shares access to the logical unit with the first host; and sending, by a computing device, a refresh message to the second host that causes the second host to update information relating to the logical data storage entity associated with the first host that includes the logical unit in a cache of the second host to reflect the occurrence of the event, wherein the data storage entity identifier associated with the data storage entity is identified as including the logical unit in the cache to indicate the logical unit is formatted by the file system of the logical data storage entity thereby preventing the second host from performing a second event corresponding to the logical unit that is inconsistent with the event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A non-transitory computer-readable storage medium containing instructions for controlling a computer system configured to:
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share a plurality of logical units in a data storage system among a plurality of hosts, wherein the plurality of logical units are available to be formatted with a file system associated with any of the plurality of hosts to form a logical data storage entity for one of the plurality of hosts, the logical data storage entity including a set of logical units from the plurality of logical units that have been formatted with the file system; receiving a notification message from a first host indicating an occurrence of an event corresponding to a logical unit of the data storage system, wherein the event relates to use of the logical unit in relation to a logical data storage entity associated with the first host that is identified by a data storage entity identifier and associated with a file system, wherein the logical unit is part of the logical data storage entity and is associated with the file system of the logical data storage entity; determining whether a second host having access to the data storage system also shares access to the logical unit with the first host; and send a refresh message to the second host that causes the second host to update information relating to the logical data storage entity associated with the first host that includes the logical unit in a cache of the second host to reflect the occurrence of the event, wherein the data storage entity identifier associated with the data storage entity is identified as including the logical unit in the cache to indicate the logical unit is formatted by the file system of the logical data storage entity thereby preventing the second host from performing a second event corresponding to the logical unit that is inconsistent with the event. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A method, comprising:
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sharing a plurality of logical units in a data storage system among a plurality of hosts, wherein the plurality of logical units are available to be formatted with a file system associated with any of the plurality of hosts to form a logical data storage entity for one of the plurality of hosts, the logical data storage entity including a set of logical units from the plurality of logical units that have been formatted with the file system; receiving a notification message from a first host indicating an occurrence of an event corresponding to a logical unit of the data storage system, wherein the event relates to use of the logical unit in relation to a logical data storage entity associated with the first host that is identified by a data storage entity identifier and associated with a file system, wherein the logical unit is part of the logical data storage entity and is associated with the file system of the logical data storage entity; determining whether an application program having access to the data storage system also shares access to the logical unit with the first host; and sending, by a computing device, a refresh message to the application program that causes the application program to update information relating to the logical data storage entity associated with the first host that includes the logical unit in a cache of the application program to reflect the occurrence of the event, wherein the data storage entity identifier associated with the data storage entity is identified as including the logical unit in the cache to indicate the logical unit is formatted by the file system of the logical data storage entity thereby preventing the application program from performing a second event corresponding to the logical unit that is inconsistent with the event. - View Dependent Claims (20, 21)
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Specification