Veritas Storage Foundation 5.1 SP1 Cluster File System Administrator"s Guide (5900-1738, April 2011)

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.
Refer to the vxfenswap(1M) manual page.
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”
on page 88.
See “Replacing the coordinator diskgroup in a cluster that is online” on page 90.
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” on page 182.
■ You want to switch the disk interface between raw devices and DMP devices.
■ 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.
See “Refreshing lost keys on coordinator disks” on page 94.
You can also use the vxfenswap utility to migrate between the disk-based and the
server-based fencing without incurring application downtime in the Storage
Foundation Cluster File System HA cluster.
See “Migrating from disk-based to server-based fencing in an online cluster”
on page 111.
See “Migrating from server-based to disk-based fencing in an online cluster”
on page 113.
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.
87Administering Storage Foundation Cluster File System and its components
Administering I/O Fencing