Great question for the hardware vendor!
On the media server where the drives are attached, add or modify
/netbackup/db/config/SIZE_DATA_BUFFERS
with contents of
262144
Inspect the storage unit defined- number of concurrent drives multiplied by multiplexing number per drive = X
Using factors of 16,24,32, 64
Add or modify
/netbackup/db/config/NUMBER_DATA_BUFFERS
with contents of
next highest number of X- 16,24,32, etc
Out of the box, NBU is tuned to be 'all things to everyone'- great if running old DLT7000 drives. Not so good for most of the higher end drives in the field today.
No restarting need, these files are read are the start of every backup.
Then check the forum for the topic of 'mulitplexing'
