To create a snapshot of an encapsulated boot disk, use the vxrootadm command. The target disk for the snapshot must be as large (or bigger) than the source disk (boot disk). You must use a new disk group name to associate the target disk.
To create a snapshot of an encapsulated boot disk
# vxrootadm -s srcdisk [-g dg] mksnap destdisk newdg
For example:
# vxrootadm -s disk_0 -g rootdg mksnap disk_1 snapdg
In this example, disk_0 is the encapsulated boot disk, and rootdg is the associate boot disk group. disk_1 is the target disk, and snapdg is the new disk group name