If the public region of the disk is intact (no further filesystems created/mounted), then it can still be recovered.
You will need old "vxdisk_list_<disk>" output of this disk. You can look for this output in any old veritas explorer if you had collected one.
Alternatively you can look for *.diskinfo file in /etc/vx/cbr/bk/<diskgroup>/ directory .. that file should have details as well.
Basically what you should look for is below information from above mentioned outputs
puboffset, privoffset, pubslice,privslice & type. Once you have all this information, you can reinitialize the disk with values found from outputs
# vxdisksetup -i <disk> puboffset= privoffset= pubslice= privslice= format=sliced/cdsdisk
Once above is done, you should be able to restore the old disk config & this diskgroup & volume info. Once this disk is back, you might need to deport & import the diskgroup again.
G
