I just added a DiskGroup

I just added a DiskGroup to VCS, and VCS offlined everything. Why?

The diskgroup you added was probably already imported manually or
through VMSA, and without the "-t" option.

vxdg import {disk group}

VCS imports diskgroups using "-t", which sets the diskgroup's noautoimport
flag to "on".

vxdg -t import {disk group}

So, when you added the diskgroup to VCS, VCS detected the new diskgroup was
imported outside of VCS because the noautoimport flag was set to "off". This
is considered a violation, and the DiskGroup Agent monitor script will then
offline the entire Service Group. This is a precaution to prevent split brain.

You can see a diskgroup's noautoimport flag by doing:

vxprint -at {disk group}

If you've imported a new diskgroup, and have not yet added it to VCS, you
can deport the diskgroup first, and then add it to VCS. You do not need to
import a diskgroup to add it to VCS.