I donlt think you mean volume pool.
Add the the new LTO2 drives as a different density than the LTO1 drives. For example, if the LTO1 drives are type hcart, add the LTO2 drives as hcart2.
Add the LTO2 tapes as the same density, hcart2.
This means the LTO2 tapes will only be allowed to be used in the LTO2 drives.
Next create a hcart2 storage unit, you will see the option to select hcart2 in the drop down, when creating a new storage unit.
Next, select this storage unit in the policy for your 'heavy backups'.
If you wish to select a different volume pool, just create a new one with the name of your choice, and select this in the policy.
If you do not use a scratch pool, you will need to add some tapes to the new volume pool.
Martin
Created: 14 Jul 2012.......NetBackup 5.1.....upgarde to LTO2.... Is topic's date correct? 
WOW - agree with Mike!
Should be looking at LTO5 library with maybe a couple of LTO3 drives do do old restores - and an upgrade to at least 7.1
As Martin says - just set the density of the new drives and tape to a different one than the originals - barcoding is good for that so that you can set a new barcode rule for the new tapes to ensure they get added as the correct density
As I can see from Sun\Oracle Handbook L700 supports LTO 4 drives. I'm not familiar with it but I suggest he can upgrade some drives up to LTO4.
