Problem Summary: After encapsulating the root disk, if you unencapsulate and then reencapsulate the root disk, you might see that a volume called uservol is used for the /global/devices/node@nodeID filesystem. This might cause problems, since the volume name for each node's global devices file system should be unique.
Workaround: After following the documented steps for unencapsulation, kill the vxconfigd daemon before you run scvxinstall again to reencapsulate the root disk.