NDMP backups not making full use of all 16 tape drives

[banjo67xxx]

banjo67xxx

6 hours 59 min ago : Link

Now I have discovered that I need to set max jobs on the STU to make full use of all the virtual drives ...

Next question: I set multiplexing to 16 in the NDMP Schedule but its still only writing to a single drive. Do I need to increase the jobs per client to get NDMP to use all 16 virtual drives, and can this be set on a per client basis? i.e. just for the EMC Data-Mover

Also, as the VTL is a de-dup device should I switch off multiplexing (now I know it doesn't affect the number of jobs started) so jobs only go to a single drive to help the VTL de-dup effeciently?

Marianne van den BergTRUSTED ADVISORPARTNERACCREDITEDCERTIFIED

6 hours 20 min ago : Link

I need to increase the jobs per client to get NDMP to use all 16 virtual drives, and can this be set on a per client basis? i.e. just for the EMC Data-Mover

Max Jobs per Client is a global setting that can be configured in Master Server Host Properties.

You can set this value on a Per Client basis in Host Properties -> Master Server -> Client Attributes.
Add Client if not already in the list, then select Client, change Max Jobs this Client.

PS:

In future - one topic per forum discussion, please!
 

Hi Marianne,

I don't know if it makes a difference, but I'm still running NBU 7.1.0.4. There is no "Max Jobs this Client" in that window (as per attached screenshot)

Please can you help me further on this point?

Thanks.

[Nicolai]

"Max job per client" is in the global attributes. It's a value (call it limitation) that apply to all backup clients.

[Marianne]

The maximum data streams is the correct field.
(I do not have access to NBU installation at the moment - I think 'Max Jobs this Client' is what it was called many moons ago...  )
Did you restart NBU on master server after this config was changed?

We need to see all config parameters to see why only one drive is used.

Please show output of the following:

bpstulist -label <STU-name> -U

bppllist <policy-name> -U

Above will be a good start - we may need more output depending on what we see.

[banjo67xxx]

I tried rebooting but that didn't work, then when you asked me to print out the policy configuration I noticed something ...

Mult. Data Streams:  no

After enabling that I now see 16 jobs start (1 parent, and 15 children 1 for each NFS share)

Device Monitor didn't show it was using all the drives, and because it took a while to login to the EMC and prepare the data streams the SAN wasn't showing traffic distributed between the drives at first. After 10 minutes I could see the traffic distributed between drives.

As its a related question, can you explain the best way to prove that multiple drives are in use from NBU?

SOLUTION: Set "Multiple Data Streams" to Yes

[Marianne]

Glad we could point you in the right direction by asking for policy config!

Not sure why you are saying this?

Device Monitor didn't show it was using all the drives

What did you see in Device Monitor?

Did you try to refresh the screen?

You can try the command line equivalent of Device monitor when backup is running:

'vmoprcmd -d' on the media server or else
'vmoprcmd -d -h <media-server>' on the master server
 

[banjo67xxx]

Thanks. That command displays accurate data but the GUI seems to be way out of date even if refrshed. I'll just use the CLI in future.

[Marianne]

It is because of Device Monitor that I started to use command line!

[Marianne]

Glad we could help you. And that you have solved your own issue.

Correction - there is NO need to reboot the master when you change Host Properties settings - a restart of NBU is all that is needed. See my post above:

Did you restart NBU on master server after this config was changed?

[banjo67xxx · Accepted solution]

I did some further testing after hitting the following issue:

http://www.symantec.com/business/support/index?page=content&id=TECH184788

and discovered that you need the following 3 settings defined ...

1) You need to set Max Data Streams in the Client Attributes (don't forget to restart the NBU master)

2) You need to enable Multiple Streams in the Policy

3) Depending upon the amount of RAM in your EMC Cellera Data Mover you may need to limit Jobs Per Policy in the Policy to either 4 or 8

[banjo67xxx]

I can't remember what the issue is on my NBU master, but I find it needs an OS reboot after an NBU restart, so I just reboot now (its dedicated to NBU so no impact on anything else). I've ammended the solution to show the recommended NBU restart.