NetBackup only creates volume names with 6 characters.
It sees all 8 of them. What you need to do is create
media ID generation rules. With these you can specify
which set of 6 characters will be used to create the
volume name (media ID). From the technote
http://seer.support.veritas.com/docs/236271.htm:

Media ID generation rules can be added to the vm.conf
file to specify the robot number and barcode length
with multiple configuration entries for each robot or
for each barcode format. With NetBackup 4.5, media ID
generation rules can also be added to the vm.conf file
via the "Inventory Robot" function of the NetBackup
administration console graphical user interface.

The media ID generation rule has the following syntax:

MEDIA_ID_BARCODE_CHARS <robot_number> <barcode_length>
<c1>:<c2>:<c3>:<c4>:<c5>:<c6>

where robot_number is the robot number, barcode_length
is the number of characters in the media's barcode
format, 
c1 is the first character of the Media ID
c2 is the second character of the Media ID 
c3 is the third character of the Media ID  
c4 is the fourth character of the Media ID
c5 is the fifth character of the Media ID
      c6 is the sixth character of the Media ID

c1-c6 can specify a character from the media barcode
or specify a fixed character by prefixing the
character with a "#".

For example, the rule:

MEDIA_ID_BARCODE_CHARS 0 8 #N:1:3:4:5:6

generates media IDs for robot 0 using the character N
and the 1st, 3rd, 4th-6th characters of the 8
character barcode, and for the barcode, 123456L1
generates media ID N13456.

The rule:

MEDIA_ID_BARCODE_CHARS 0 8 1:2:3:4:5:6

generates media IDs for robot 0 using the 1st-6th
characters of the 8 character barcode,  and for the
barcode 006498L2 generates media ID 006498.

Thanks,

Jeff Redington


"A wise man once said 'Wherever you go, there you are'"
      -Mike Brady