Claims
- 1. A method for transparent failover of a root filesystem made unavailable by the failure of an active server node on which the root filesystem is mounted within a computer cluster having a number of other nodes, the method comprising the steps of:placing all application processes currently performing any operations requiring access to the root filesystem in an interruptable sleep state; mounting the root filesystem within a standby server node in the computer cluster; creating a server instance associated with the root filesystem and re-associating the server instance with each of the other nodes in the computer cluster; awakening the application processes placed in an interruptable sleep state and making the root filesystem available on a read-only basis to each of these application processes; checking the integrity of the root filesystem; completing the application processes interrupted by the failure of the active server node; and making the root filesystem available within the computer cluster on a read-write basis to new application processes.
- 2. A method as recited in claim 1 further comprising the step of configuring the server instance to reflect the state of the root filesystem prior to failure of the active server.
- 3. A method as recited in claim 1 wherein the step of configuring the server instance further comprises the steps of:rebuilding token state within the server instance; rebuilding record locks within the server instance; and rebuilding the state of open-unlinked files within the server instance.
- 4. A method as recited in claim 1 further comprising the step of re-associating the server instance with client instances within the computer cluster.
- 5. A method for providing filesystem failover in single system image computer cluster environment having a shared file system mounted to an active server node and a number of alternate nodes which share the file system, with at least one node performing a non-idempotent operation on the filesystem, and where the failover occurs before the non-idempotent operation is complete, the method comprising:registering the non-idempotent operation currently being performed on the filesystem; locking all resources needed to perform the operation; determining an estimated result of the operation and storing the estimated result; detecting the failover before the operation is complete; placing the operation in an interruptable sleep state; mounting the filesystem within a standby server node in the computer cluster; creating a server instance associated with the filesystem and re-associating the server instance with each of the other nodes in the computer cluster; awakening the operation placed in an interruptable sleep state and completing the operation interrupted by the failure of the active server node; and checking an actual result of the operation with the estimated result in order to determine the integrity of the filesystem.
- 6. The method of claim 5, further comprising the steps of:updating the filesystem; and making the filesystem available within the computer cluster on a read-write basis.
RELATED APPLICATIONS
The following application claims the benefit of U.S. Provisional Application Serial No. 60/066,012 entitled “Filesystem Failover in a Single System Image Environment” by Bruce Walker, filed Nov. 4, 1997, the disclosure of which is incorporated in this document by reference.
The following co-pending patent applications, which were filed on Apr. 30, 1998, are related to the subject application and are herein incorporated by reference:
Application Ser. No. 09/070,897, entitled “Filesystem Data Integrity in a Single System Image Environment” of Bruce J. Walker, David B. Zafman and William W. Chow.
Application Ser. No. 09/071,145, entitled “Filesystem Failover in a Single System Image Environment” of Bruce J. Walker, John L. Byrne, William W. Chow, John A. Gertwagen, Laura L. Ramirez and David B. Zafman.
US Referenced Citations (17)
Non-Patent Literature Citations (2)
Entry |
Compaq, Compaq NonStop Clusters for SCO Unix Ware, http://www.tadem.com/prod des/ncunixpd/ncunixpd.htm, pp. 5, Sept. 1999.* |
Sun Microsystems, “The NFS Distributed File Service-Preserving File Intergrity,” NFS White Paper, http://www.sun.com/software/white-papers/wp-nfs/nfs 13.html;$sessionid$IE2QZTIAAYC3JAMUVFZE5YQ#34514, Mar. 1995, pp.1-2. |
Provisional Applications (1)
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Number |
Date |
Country |
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60/066012 |
Nov 1997 |
US |