Ask the Expert: Networker Server Best Practices

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Regards,

Mark

Hello Mark. Do I have to buy an additional license for adding a new backup client?

Question to Prajith; there is a confusion on the market what is the right approach with number of devices, target sessions and max sessions, especially with recent 7.x and 8.x code.  Can you share more details on that?  For example, traditioally we tried to have 1 session to 1 device as much as possible - even disk.  However, it seems as with DD this has changed and to get best performance you might even have to push multiple sessions onto single device (bare in mind that I refer here to DD). This might be good news for those who wish to scale down their device portfolio.  In such case, is this related to specific DDOS and NW version or both recent codes subscribe to same feature?

Hello, Prajith.

Do I have to buy an additional license for adding a new backup client?

Kevin wrote: Hello, Prajith. Do I have to buy an additional license for adding a new backup client?

Seems like Prajith is sleeping   In short, if you miss license, you do need one.  How it works?  Like this:

- go to backup server and execute nsrcli command... you should see something like this among other things

STANDARD CLIENT LICENSES                      Available: 712                           Used: 197              Loaned to Virtual: 0                      Remaining: 515              Connected Clients                                      VIRTUAL CLIENT LICENSES                      Available: 52           Borrowed from Server: 0                           Used: 51                      Remaining: 1              Connected Clients                                         NDMP CLIENT LICENSES                      Available: 6                           Used: 5                      Remaining: 1

As you can see, Available is your total count and Used is what is used.  With that in mind, and some simpple math, Remaining is what determines if you need new licenses or not.

If you use virtual client licenses, and if your new client belongs to physical host which is already licensed, then no new license is needed (just make sure that virtual client+physical client name is filled in NSR client resource for new client).

Hi Kevin,

Sorry for delayed respose.You need additional license for adding new clients.

Use this license key  :   70f2f2-2a8c02-d8e43a

This is a 25 client license. You can use it for 30 + 15(grace) days.

Regards,

Prajith

Hello Hrvoje,

Thanks for reply to Kevin's post. I was away for a day and was not able to reply to the post.

In general considering normal tape drives and AFTD's, there is no specific recommendation about the target sessions and max sessions. These are determind by the number of save sessions getting generated and how exactly it should be written on to tape.

1 session to 1 is usually used to save the data to single tape. That means you will have data on one tape and restore needs just one tape. This will make restore faster.

Now a days we can see the tape drives like LTO 5 and LTO 6 which can write at a speed of 140 and 160 MBPS respectively. If the client cannot send data at the same speed then the complete drive speed cannot be utilized. In these scenarios its better to multiplex the data from deffrent clients.

In case of DD, please confirm if you are refering to normal DD device or a DD VTL.

I can provide you suggestion accordingly.

Regards,

Prajith

Hi Prajith,

I was referring to DD device type (boost). 

Hello Hrvoje,

However, it seems as with DD this has changed and to get best performance you might even have to push multiple sessions onto single device (bare in mind that I refer here to DD). This might be good news for those who wish to scale down their device portfolio.

Ans:

NetWorker started using DD Boost feature after the release of NetWorker 8.0 in client and storage node. Earlier to this, only NMM 2.3 did had DD Boost feature enabled in it.

NetWorker client and storage node with DD Boost can perform up to 60 concurrent backup and recovery sessions (save streams) per DD Boost device.This high use of sessions reduces the number of devices needed and thereby reduces the impact on the Data Domain system performance and maintenance.

In such case, is this related to specific DDOS and NW version or both recent codes subscribe to same feature?

Ans:

I am not much sure about any recommendation done from DDOS side. We may need to do more research on DDOS part.

Regards,

Prajith

Hi Prajith,

I have second question, also related to stream/performance management - this one is focussed on NW8 solely.  In NW8 we have something as following by default (out of the box):

Above is oob example for one DD dev type device.  I created 4 of those.  In old days, depending if that was tape or aftd, I would have 4 to 8 nsrmmd devices created (one for device and in case of aftd 2 per device).  With nw8, and 8 devices, I did get 32.  The only match which makes sense is that you nsrmmd count to be device x max nsrmmd count.  As per documentation, at least one is always reserved for restore/cloning.  Do you know how the others are being used?  I ask this because I wish to understand how these nsrmmd are utilized and why max nsrmmd count is below target session one. 

Further, if you go step further and try to dynamic nsrmmds, you will end up with even more nsrmmds as dynamic setting will use formula like max/target +4 which gives you 60/6+4=14 nsrmmd processes. Obviously, from 4 to 14 there alot and the only way to make a good call on configuration and tuning is to understand how this nsrmmd processes are utilized and what is the theory of operation behind. Of course, I could not find any document which addresses this part so I'm hoping you can share some wisdom on this.  Thnx.

Hello Hrvoje,

I would recommend you to go through this Document,

https://support.emc.com/docu44910_NetWorker-and-Data-Domain-Release-8.0-SP1-Integration-Guide.pdf?language=en_US

Chapter 1 > Features > DD Boost Integration.

This will provide you more details on NetWorker and Data Domain integration.

Let me know if this helps.

Regards,

Prajith

Hey Prajith,

I read that document and it does not provide anwer to my question.

Hi Prajith,

It is misleading to say that boost feature has started to be used in nw8.  I use boost with Oracle and SAP using both NMDA and NMSAP and NW7. NW8 took it further and brought boost support to level of file system backup too (previously only storage node backup part of file system backup utilized boost).  As for sessions, 60 is max session value when using DD dev type... (and up to 10 is recommended as per NW documentation).

However, what is not clear is what do we do with target sessions - is it 1 as before or more?  That was the purpose of my question - if this can be clearly clariflied and/or researched I would appreacited it as I could not find any documet or white paper giving clear answer on this (thus my question here). For example, table above says it is 6 (which is default value in out-of-the box installation for 8.0.0.x); however same documentation will also claim that default is 1 later on so things are a bit messy in that compartment.  If EMC could have made white paper (just as they did for VTL multiplexing enhacement with DD and NW nsrjobd improvement) showing old and new state with clear test cases and result, it would be more clear I assume. Do you know if such document is planned to be released?

Thanks for letting me know. Let me do some more research on this and get back to you.

Regards,

Prajith