Master Serrver Properties - Bandwidth (NBU 7.5.0.7)

[John_Snodgrass]

When you set the Bandwidth throttle setting for a set of hosts, I'm not sure if that is the total amount it will use or is that the limit for each job in a multi-stream policy.  For example:   From Host Master_A to Host Client_1 Bandwidth 100kb/sec.  I have a job with multi-streaming on, with the backup selections all_local_drives.  The parent job starts up and fires off eight child processes.  Four go avtive as the limit per client of four is reached, leaving 4 queued.  Will the 4 active use 100kb each for a total of 400kb/sec pulled from the client interface, or do all four active jobs share the 100kb/sec limit..  I have a customer askimg me as they are seeing higher traffic on their interface then they were expecting.

Thanks in advance to the group.

[RiaanBadenhorst · Accepted solution]

Some info

The bandwidth limits only restrict bandwidth during backups.

Consider the following items about bandwidth limits:

• Certain policy types to do not allow for bandwidth throttling. The following is an example log from NBJM (OID 117) that indicates that throttling is not used:

• 18/01/2012 12:57:44.552 [Debug] NB 51216 nbjm 117 PID:8100 TID:13428 File ID:117 [jobid=679260 parentid=679259] 1 [BackupJob::startThrottle] (02503528) throttling not needed for this job(BackupJob.cpp:2953)

• See www.symantec.com/docs/TECH153326 for a list of affected policy types.

• Bandwidth limits have no effect on a local backup (where the server is also a client and data does not go over the network).

• Bandwidth limits restrict maximum network usage and do not imply required bandwidth. For example, if you set the bandwidth limit for a client to 500 kilobytes per second, the client can use up to that limit. It does not mean, however, that the client requires 500 kilobytes per second.

• You cannot use bandwidth limits to distribute the backup workload of active backups by having NetBackup pick the most available network segment. NetBackup does not pick the next client to run based on any configured bandwidth limits.

[John_Snodgrass]

All good information, but does not address my question.  My gut feeling is it is a limit for all jobs combined, but my customer is telling me they are seeing numbers higher then what we set the limit to.  Hence my question.

[Andy_Welburn · Accepted solution]

This probably doesn't help any (or maybe it does?) but the following is in the 6.5 Admin Guide and the context sensitive help for 'bandwidth' & yet does not appear in the guide for 7.5:

As the number of active backups increase or decrease on a subnet, NetBackup dynamically adjusts the bandwidth limits on that subnet. If additional backups are started, the NetBackup server instructs the other NetBackup clients that run on that subnet to decrease their bandwidth setting. Similarly, bandwidth per client is increased if the number of clients decreases. Changes to the bandwidth value occur on a periodic basis rather than as backups stop and start. The periodic changes reduce the number of bandwidth value changes that are required.

Which indicates it is (was) an overall limit for the sub-net ..... not sure if anything changed in the interim?

[RiaanBadenhorst · Accepted solution]

If the backup type is on the list of ones that adhere to the rules it would be relevant. As for the limit i agree on it being total for the client.