Guidelines for changing NetBackup appliance FT target ports to receive data streams from multiple SAN Client FC initiator ports
|Article:HOWTO94419|||||Created: 2013-11-26|||||Updated: 2014-05-05|||||Article URL http://www.symantec.com/docs/HOWTO94419|
If you want an appliance Fibre Transport (FT) target port to handle data streams from more than two SAN client Fibre Channel (FC) initiator ports concurrently, consider changing the following NetBackup master server setting:
nbftconfig - setconfig - ncp 4
This setting applies to all target ports on all FT media servers in your NetBackup domain. This setting should only be increased from the default (2) when all of the following conditions exist:
All FT target ports on all FT media servers are eight gBit/s link speeds.
The total mix of FT jobs is such that all of the FT media servers have unused FT pipes.
A large number of jobs from other SAN Client machines are waiting for resources.
The back-end storage units have a lot of unused throughput capacity.
If you increase the - ncp setting too high, the load balancing between multiple FT media servers when all SAN Client machines are zoned to all FT media servers could become highly imbalanced.
A mix of SAN Client job loads where some clients use four or more FT pipes concurrently with several other SAN Clients that only attempt to use a single FT pipe at a time increases the odds that a higher - ncp setting may cause FT media server imbalance.
For four gBit/s links, there may be situations where overall throughput can degrade when some or all SAN Clients are using multiple concurrent data streams. This scenario may be especially true for NetBackup 5220 appliances. In those situations, nbftconfig - setconfig - ncp 3 may be a better option.
Article URL http://www.symantec.com/docs/HOWTO94419