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| About the vxfenswap utility | ||
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| Prev | Administering I/O fencing | Next |
The vxfenswap utility allows you to add, remove, and replace coordinator points in a cluster that is online. The utility verifies that the serial number of the new disks are identical on all the nodes and the new disks can support I/O fencing.
This utility supports both disk-based and server-based fencing.
The utility uses SSH, RSH, or hacli for communication between nodes in the cluster. Before you execute the utility, ensure that communication between nodes is set up in one these communication protocols.
Refer to the vxfenswap(1M) manual page.
See the Cluster Server Installation Guide for details on the I/O fencing requirements.
You can replace the coordinator disks without stopping I/O fencing in the following cases:
The disk becomes defective or inoperable and you want to switch to a new disk group.
See Replacing I/O fencing coordinator disks when the cluster is online.
See Replacing the coordinator disk group in a cluster that is online.
If you want to replace the coordinator disks when the cluster is offline, you cannot use the vxfenswap utility. You must manually perform the steps that the utility does to replace the coordinator disks.
New disks are available to act as coordinator disks.
See Adding disks from a recovered site to the coordinator disk group.
The keys that are registered on the coordinator disks are lost.
In such a case, the cluster might panic when a network partition occurs. You can replace the coordinator disks with the same disks using the vxfenswap command. During the disk replacement, the missing keys register again without any risk of data corruption.
In server-based fencing configuration, you can use the vxfenswap utility to perform the following tasks:
Perform a planned replacement of customized coordination points (CP servers or SCSI-3 disks).
See Replacing coordination points for server-based fencing in an online cluster.
Refresh the I/O fencing keys that are registered on the coordination points.
See Refreshing registration keys on the coordination points for server-based fencing.
You can also use the vxfenswap utility to migrate between the disk-based and the server-based fencing without incurring application downtime in the VCS cluster.
See Migrating from disk-based to server-based fencing in an online cluster.
See Migrating from server-based to disk-based fencing in an online cluster.
If the vxfenswap operation is unsuccessful, then you can use the -a cancel of the vxfenswap command to manually roll back the changes that the vxfenswap utility does.
For disk-based fencing, use the vxfenswap -g diskgroup -a cancel command to cancel the vxfenswap operation.
You must run this command if a node fails during the process of disk replacement, or if you aborted the disk replacement.
For server-based fencing, use the vxfenswap -a cancel command to cancel the vxfenswap operation.