How Does the Media Server Load balancing works?

[Luiz_Prina]

Hello,

I was trying to finger out how the media server load balancing works. I have a fell sug's configured on our environment. But here comes the question:

If I set just one storage unit for a sug,  Will the jobs be balanced using the storage unit configuration? (We can pick all the medias servers, selecting : Only use the following media servers from Storage unit's tab)

or

I must have to pick at least 2 storage units for a proper sug configuartion.

Thanks in advance.

[Marianne]

There is absolutely no point in having only one STU in a STUG.

What do you expect to see with one STU in a STUG?

Have you seen the explanation for media server load balancing in NBU Admin Guide?

Media server load balancing

The Mediaserverloadbalancing option indicates that NetBackup select a storage

unit based on a capacity-managed approach. In this way, NetBackup avoids sending

jobs to busy media servers.

If a storage unit is unavailable, NetBackup examines the next storage unit until

it finds one that is available.

The selection is based on the following factors:

■ The rank of the media server.

NetBackup considers the number of processes that are running on each CPU

along with the memory thresholds on each server to determine the rank of a

media server. If the free memory drops below a determined threshold, or if

the number of running processes per CPU rises over a determined threshold,

then the overall rank of the media server drops.

■ The number of jobs on the media server.

NetBackup considers the number of scheduled jobs on each media server.

■ Whether the media server has enough disk space to accommodate the estimated

size of the image. (Physical and virtual tapes ignore this requirement.)

NetBackup estimates the size of any of the new or any current jobs on each

media server. It then determines whether the jobs fit on a given volume.

NetBackup estimates the amount of space that the job may require, based on

previous backup history. If no history is available, the high water mark for the

storage unit serves as a guide.

The above can obviously only be applied if you have 2 or more STUs, right?

[Luiz_Prina]

Hello Marianne,

Thanks for you replying. I saw that on admin guide as well. But it does not mention the parameters. As an example:

"NetBackup considers the number of processes that are running on each CPU

along with the memory thresholds on each server to determine the rank of a

media server." Which number is it?

Regards

[revarooo]

What do you mean which number? It probably work out % usage when it comes to CPU/Memory and if 1 media server has 10 jobs running and another has 5, it will use the one with 5.

Why the need to worry about it? Let NetBackup just get on with it.

[Marianne · Accepted solution]

Same here... I have no idea what you are asking...

Best to setup a test environment with 2 or more media servers, add them to STUG, 

Add enough jobs to run to the STUG and see what happens...