About the vxfenswap utility
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About the vxfenswap utility

The vxfenswap utility allows you to replace coordinator disks 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 also supports server-based fencing.

Refer to the vxfenswap(1M) manual page.

See Veritas Cluster Server Installation Guide for details on the coordinator disk 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 diskgroup.

  See Replacing I/O fencing coordinator disks when the cluster is online

  See Replacing the coordinator diskgroup 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.

  See Replacing defective disks when the cluster is offline

• You want to switch the disk interface between raw devices and DMP devices.

  See Changing the disk interaction policy in a cluster that is online

• New disks are available to act as coordinator disks.

  See Adding disks from a recovered site to the coordinator diskgroup

• The keys that are registered on the coordinator disks are lost.

  In such case, the cluster might panic when a split-brain 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.

  See Refreshing lost keys on coordinator disks

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

If the vxfenswap operation is unsuccessful, then you can use the -a cancel option 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.