NDMP using simultaneous tape drives?

[Rottweiler]

Hello all, I'm currently running a NB 6.0 config. My setup is one adic 100 with 4 tape drives. Two of the drives have been zoned for NDMP backups of the NAS data movers. When running test backup jobs, only one drive is being used, while all other jobs go into 'queue' mode until the job ahead of it is finished. My question is, can the drives be configured to be in use at the same time handling different NDMP jobs? If so, is that a NAS config or something I could do in Netbackup?



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[estech25]

Well, it depends on a lot of things.
1. How have you defined your NDMP Storage Unit? Does it allow for use of two concurrent drives? You may wanna double check the property Maximum Concurrent Drives.

2. How have you defined your NDMP backup policies? If there is only one policy with one NDMP host, then it might not be possible to break the job into concurrent ones. Make sure your policy and backup selections definitions provide for use of two concurrent drives

Let me know if this helped or not.

 

[hpuxrules]

I currently run Netbackup Enterprise 5.1 MP3 and have two direct connected AIT4 tape drives to my EMC NS600 NAS filer.

My NDMP Storage unit is configured with 'max concurrent drives' set to 2.

I have 5 volumes I am backing up (about 2TB total) and had to enable 'Allow Multiple Data Streams' for my NDMP backups to utilize both tape drives simultaneously.

Hope this helps.

 

[Rottweiler]

Well, multiple data streams means that several streams from the same job will write to the drive. I'm told by a Veritas engineer that the simultaneous use of both drives is impossible.



A discussion is ONE topic. A conversation is MANY topics.....

 

[hpuxrules]

The technician you have been speaking with at Symantec is incorrect. I have been using multiple tape drives with NDMP for over a year.

I believe you may be confusing 'multiplexing' with 'Multiple Data Streams'.

'Multiplexing' writes multiple data streams to a single tape drive, meaning that multiple filesystems (i.e. /, /opt, /home) can each have streams running simultaneously, and writing to a single tape drive.

'Multiple Data Streams' writes multiple data streams to multiple tape drives. Hence /VOL1 would go to one tape drive, /VOL2 would go to another tape drive. All other /VOLs would be queued until a tape device became available.

NDMP backups do not support multiplexing, therefore you should not have more than one data stream writing to a single tape device at any given time.

Hope this helps.

 

[Rottweiler]

So the engineer was right when he said that simultaneous NDMP jobs are not allowed. Bottom line is, it can't be done.


A discussion is ONE topic. A conversation is MANY topics.....

 

[hpuxrules]

Are you talking about sharing your NDMP tape drives with another NAS filer (using SSO)?

I.E. Two NAS filers trying to backup to multiple tape drives at the same time?

If so, I have no experience with that.

My tape drives are direct connected to my NAS filer...not zoned through my fabric (yet).

 

[Stumpr]

SSO for ndmp is available with 6.0

Bob Stump
Just because the VERITAS documentation states a certain thing does not make it a fact and that is truth.

 

[Rottweiler]

Let me clarify my question. I have TWO datamovers. Let's call them datamover1 and datamover2. I have an ADIC tape library with 4 tape drives in it. Two of the drives are set up for regular backups over a SAN. The other two drives are zoned exclusively for NDMP backups off of a NAS. When backup up data from datamover1 and datamover2, whichever job started first will use only ONE tape drive while the other datamover job remains in queue until the first datamover job finishes. Since there are TWO drives dedicated for NDMP backups, why doesn't Veritas allow for SIMULTANEOUS use of BOTH tape drives?

A discussion is ONE topic. A conversation is MANY topics.....

 

[GreyWanderer]

zone 1 datamover to one drive, the other datamover to the other drive. Config NBU accordingly.