Chapter 10. The GFS Withdraw Function

The GFS withdraw function is a data integrity feature of GFS file systems in a cluster. If the GFS kernel module detects an inconsistency in a GFS file system following an I/O operation, the file system becomes unavailable to the cluster. The I/O operation stops and the system waits for further I/O operations to error out, preventing further damage. When this occurs, you can stop any other services or applications manually, after which you can reboot and remount the GFS file system to replay the journals. If the problem persists, you can unmount the file system from all nodes in the cluster and perform file system recovery with the gfs_fsck command. The GFS withdraw function is less severe than a kernel panic, which would cause another node to fence the node.

You can override the GFS withdraw function by mounting the file system with the -o errors=panic option specified. When this option is specified, any errors that would normally cause the system to withdraw cause the system to panic instead. This stops the node's cluster communications, which causes the node to be fenced.

For information on the GFS withdraw function, see Global File System: Configuration and Administration.