Hello,
vxtool is used to clear the SFW Private Region from a disk and would be used in instances when you were attempting to destroy a Disk Group or remove a problem Disk that has a corrupted private region on it. The resetmbr clears the private region and writes a new signature to the disk.
If you are simply trying to add a disk that is currently in the Basic Group to a Disk Group, vxtool should not be used. If there is no signature on the disk, you can simply right-click the disk in VEA (left-pane view) and choose the 'write signature' option. From there, you can write a signature to one, a selected number of disks, or all of the disks.
Once a signature is written to the disk, the Disk will be available to add to a Disk Group.
If this does not assist you, please provide more detail on the specifics of your issue.
I hope this helps.
- Robert