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Share Media Server same Tape Pool

Scott_Thornberr
Level 4

Ok, now I am second questioning something...

to make this simple:

 

1 media server to tape Lt3 Pool A

add a second Media Server to share the drives/robots/ SSO and media license we purchased etc.

Can Media Server 2 also use Tape Pool A?

 

I ask becuase I see for media there is a "media Owner colum" and I cant recall the rules for this.

basically from the past in checking I was told no problem, create a shared storage pool and it does not matter, but when I look at this I am questioning it as to me it seems if Media Server 2 uses a tape it does it become "sole owner of it" and it would make sense to me to separate the pool.

 

Any thoughts?

 

Thanks

Scott

1 ACCEPTED SOLUTION

Accepted Solutions

Marianne
Moderator
Moderator
Partner    VIP    Accredited Certified

The default behaviour across all NBU versions is media ownership. The media server who first writes the tape owns it. Once all images expire, it becomes available and another media can write to it and assume ownership.

NBU 6.5 introduced media sharing that can be done in two ways: Media Server Groups - media servers in a particular group can all write to same media, or Unrestricted Sharing (enabled in Host Properties) where ALL media servers can share ALL tapes. Media Sharing has to be enabled by the backup Admin.

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10 REPLIES 10

J_H_Is_gone
Level 6

I have 4 media servers using the same volume pool.

Yes when a media server takes a tape and buts backups to it that media server is listed as the owner.

If a restore request comes in for data on that tape, that media server will be asked to do the restore ( you can set the fail-over for restores to allow any body to do them if the media server is unavail)

The only real issue here is if media server A has a tape and does backups, and media server B has tapes and does backups.....

and media 1 gets full media server A will take another tape, as it cannot send data to a tape this is currently being backed up to by media Server B.

Once a tape is owned by a media server no other media server will use it, unless it is forced to by a restore.

Dion
Level 6
Certified

By default this is the normal behaviour for NetBackup.  This can amount to a large wastage of tapes, especially if you are vaulting your tapes to offsite.  By default, tapes will not be shared between media server owners and this can translate to a large number of tapes being used, even if you are not backing up much data.

I think it is from version 6.5 where you can set up Server Groups to use media sharing (under Media and Device Management>Devices>Server Group).  Here you can create a server group and assign media servers to that group between which you want to share the same media.  You will then be able to configure the policies to use the shared server group as the Media Owner (under the Attributes tab for the policy).

Hope this helps.

Dion
Level 6
Certified

Hi again

I might have read you question slightly wrong so this is an attempt to redeem myselfsmiley

As J.Hinchcliffe mentioned, media servers can use tapes from the same pool without issues.  If you don't have media sharing enabled (my previous post) the tapes that are in the same pool will be owned by the media server that first writes data to it.  By default this tape will not be loaded by another media server for both writes or restores (again, as J.Hinchcliffe mentioned in his post).

If you want to bypass this behaviour by allow different media servers to share tapes between them, you can enable the media sharing feature (as in my previous post).

Cheers

Scott_Thornberr
Level 4

Hi Guys:

 

Your response is right on, as my thoughts were media server a would own the tape and media server b would now not use it.

Dion:  I am looking into the Server Group item you mention to better understand this, interesting as I sent this question to Symantec and this is thier response:

"

SOLUTION/WORKAROUND:
As long as the storage units are the same density you can have two or more storage units pulling tapes from the same media pool.
Even if the tape is written to by Media server A, if their is free space, then Media server B can also write to the same tape.
The Media Owner is not really important. It is just information and will show the last media server that wrote to the tape."
 
However I am now reading on the Server Group and this explains what your guys were saying about wasting tapes etc, so thanks for pointing me in the right direction, as I was looking at the tapes and my thoughts were hmm, mediaA owns it, now mediaB wont use it
 

Marianne
Moderator
Moderator
Partner    VIP    Accredited Certified

The default behaviour across all NBU versions is media ownership. The media server who first writes the tape owns it. Once all images expire, it becomes available and another media can write to it and assume ownership.

NBU 6.5 introduced media sharing that can be done in two ways: Media Server Groups - media servers in a particular group can all write to same media, or Unrestricted Sharing (enabled in Host Properties) where ALL media servers can share ALL tapes. Media Sharing has to be enabled by the backup Admin.

Scott_Thornberr
Level 4

Hi There:

 

Ok from what Mariannne is saying

sounds like I DONT need Server Groups but only to enable media shareing.

This lead me to look at the tap and here is what I found and sounds like that needs to be done, to simply allow BOTH Meida servers share the media if they need to.

 

I need to also explain, media Server A is on one network

Media Server B is on another network, this is allowing me help improve traffic flow for clients on both sides, but allow clients in either side, should they need a tape write to it which may not be the best ideal, but then it would depend on how I want to keep this clean at which point.

 

From the book, media shareing is actually off by default:

 

 

To allow all NetBackup media servers and NDMP hosts in your NetBackup environment to share media for writing, select this property. Do not configure server groups for media sharing.

To restrict media sharing to specific server groups, clear this property, then configure media server groups and backup policies to use media sharing.

To disable media sharing, clear this property and do not configure media

server groups. By default, media sharing is disabled

 

Scott

Scott_Thornberr
Level 4

One more item if anyone is reading this or cares,

when you enable this, it will apply to media that has not been assigned yet, so

if you have media already assigned, it wont be shared until you clear it or make it a scratch again.

 

Thanks to all of you who got me in the right direction for this, as this question was burning in my head, and I guess I couldnt find the right words to look it up correctly what I was looking for.

 

Andy_Welburn
Level 6

If you're happy that the media sharing option is the way to go & has resolved/will resolve your issue, please come back & mark Mariannes post as the solution. yes

Scott_Thornberr
Level 4

hmmm I thought I did mark them, as thanks to Dion and Marianne

they got me in the area I needed, I do apoligies let me check what I did or did not do.

 

Again thanks for the  feed back as I knew what I needed but didnt know the right combination to look at and this is what I was looking for.

Andy_Welburn
Level 6

That could be my bad - sorry!