Onkar

• Dec 30th, 2016

 

There is no "fixed" number as such in my view. Whenever the general performance starts to drop, you have overloaded the servers.

One example for illustration only:

1 drive 250MB/sec Combined speed 250

2 drives 240 MB/sec Combined speed 480

3: drives 200MB/sec Combined speed 600

4 drives 140 MB/sec Combined speed 560

5 drives 80 MB/sec Combined speed 400

In this scenario its pretty obvious the sweet spot is 3-4 drives. But its very individual from media server to media servers. Distribution of tape drives amount fibre channel HBA, network and SAN load all contribute to the maximum possible load.

Virtual tape drives are in reality disk, so the "shoe shining" effect does not apply.

If not already done so configure NUMBER_DATA_BUFFERS/SIZE_DATA_BUFFERS in Netbackup. How to do is documented in the symantec . com/docs/DOC7449

Configuration of buffer is the number one teak in Netbackup. Go for 262144 in SIZE_DATA_BUFFERS (default value) and 256 or larger for NUMBER_DATA_BUFFERS