Backup & Recovery

Introduction

The question is often asked if there is still a use for the Frequency Based Scheduler. Why not simply use the Calendar based scheduler for ‘everything’?

Problems often experienced:

  • Backups being skipped
  • ‘schedule creeping’ – backups kicking off later than they ‘should’

Frequency – good or bad?

Unknown is unloved.

Once Backup Administrators get to know and understand the frequency based scheduler, it becomes the no. 1 choice for regular backups such as daily and weekly schedules.

Understanding the basic test logic of Frequency based scheduling is key.

The older NetBackup Admin Guides contained an excellent flowchart explaining the process.

Extract from NBU 5.1 Admin Guide II:  http://www.symantec.com/docs/TECH32131

Building the Worklist (Queue)

When the backup window opens for an automatic backup schedule, NetBackup proceeds to determine whether or not to add the client backups for that schedule to the worklist (queue). The following figure shows this process:

Frequency.jpg 

Frequency Based Backup Article

Industry expert David Chapa has written an article explaining how to best use Frequency based schedules.  David has kindly shared his article to be published on Connect.

Please find document attached:

Comments

Thank you Marianne for sharing this excellent article. All these days, i've been ignoring this kid as i had no idea on what he is capable of. Now i stand corrected and would like to play with this kid.

Thanks for posting this Marianne.

 

I am very happy so many have found value in this article.

 

-David

-----------------------------

David A. Chapa

CTE, office of CTO

Quantum Corporation

David, thanks for sharing this article. I feel that it is now in its rightful 'home'.

I have in the past often referred Connect Users to the original NetApp blog, e.g
https://www-secure.symantec.com/connect/forums/schedule-backup-frequency-vs-calender-type-backup#comment-4549641
https://www-secure.symantec.com/connect/forums/multiple-data-streams-not-starting#comment-5486571
https://www-secure.symantec.com/connect/forums/full-backups-not-running-schedule#comment-3155981
etc... etc...
just to find that it's been removed in the meantime.

Just a pity that the article is now under my name instead of yours!

quick question, if i wanted to be lazy and keep it simple and set the freq to 1 day for all schedule. What load does it put on the nbpem's worklist?

 

Thanks,

~Rookie

No additional workload...

As explained in the article, you run the risk of 'schedule creeping'. Every 1 day means 24 hours after last successful start time. If previous backup was queued for any reason, the start time for future backups will be moved to a later time.

Thanks for Sharing Marianne.

& thanks for re-"sourcing" it Marianne. I too have referenced it on several occasions & was somewhat disconcerted to find it had disappeared...

Marianne,

Excellent work. I have one question. When determining if the retention levels are the same (for scheduling purposes), does the “scheduler” use the retention level in the policy or in the storage lifecycle policy (assuming one is used)?

Hi Patrick

The SLP determines retention.

Best to create separate SLPs for Daily, Weekly, Monthly, etc. schedules, then select relevant SLP as STU in the schedule.

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