Question

Aux Copy - how to use all free tape drives unless another job needs a drive?

  • 25 March 2023
  • 2 replies
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I have a library with 2x LTO drives that is used for some direct to tape jobs and for aux copies of some disk jobs.

Ideally what I’d like is for both LTO drives to be free to aux copy data but if another job runs that needs a drive for the aux copy to throttle back down to using one drive.

So for example right now I have 50TB of data to aux copy that is going to a single drive when it could go to both drives (I’ve got them so why not use them) except if I set the aux copy to do that it seems that any new backup jobs to tape pause with “no resources available”.

Thanks 😀


2 replies

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Hello @Paul Hutchings 

 

Thanks for the great question, it is going to be a hard one to achieve on a dynamic level inside the same Aux copy job. The Aux copy job settings around amount of streams and drives to use are set at the beginning of the job and cannot be changed on the fly. 

 

I would recommend killing the active Aux copy job when backup jobs are scheduled to run, submitted a new Aux copy job to run that has the setting to only use the one tape drive and then revert this back once the backup jobs are complete. 

 

The only way to automate this process would be with scheduling and max run time. If you know how long your backup jobs run for you could make it so the Aux copy job kills it self before they start and a new schedule with the new drive settings takes over and then kills its self after X amount of hours. After this the original schedule with 2 drives takes over. 

 

The above process is very messing and overly complex for a simple issue. If this Aux copy data is a one off backlog i would not bother with this and just simply resubmit the job when you are in your backup window. 

 

Please note that killing a Aux copy job has no effect on the data it has processed to that point, it will check point and the next job running will pick up where it left off. 

 

Kind regards

Albert Williams

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Hi Paul,

I have the same situation in my environment. I was also thinking about that.

 

My solution is: I’m suspending the aux copy jobs manually when I’m spotting a backup job which is waiting for free tape drives. In the suspend dialog window (Commcell console), I’ll check the mark for “Auto resume” in 30 minutes. As soon as the aux copy jobs enter the suspended state, the other backup job grabs the tape drive.
The other backup finishes very often in less than 30 minutes, so the aux copy jobs can go back to work automatically.

 

Though, I’d be happy if there would be an option “use a maximum of 4 tape drives, but only use 2 tape drives if there are other jobs”.

 

Regards,

Bernd

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