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DB maintenance: Database Index Fragmentation

  • 13 February 2023
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We have a Database Index Fragmentation message in our Health Check. If I want to run a DB maintenance run -full, it is recommended to deactivate the scheduler. Are there any experience reports, how long such a maintenance run could run ? 

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Best answer by Laurent 14 February 2023, 10:17

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Hi @thomas.S 

Depends on your environment and activity, commserve DB size, load on Commserve at the moment..

 

I execute it during the day, where there are almost no activity and right after the last execution of a schedule, and it takes from a few seconds to a few minutes.

But my CS DB is small, and activity at this time is low, my CS VM is big with lots of resources 😀 

 

Regards,

Laurent.

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Hello @Laurent

this is the size of our CommServe DB. 
 

Because of the end of our Companies Fiscal year we should avoid making any changes on our systems if not nessesarry. 
We performed the last maintenance about a year ago.. 
What do you think.. could we wait another 3 weeks or should we do this as soon as possible.

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hi @thomas.S 

Yours is 2x smaller than mine.

My VM executing the CS is 64GB Ram/12vCPUs, full SSDs.

Today at 11:32AM it ran one, and it got complete by 11:39AM, only a few auxcopies and 10 FS backups jobs were running at that moment (which is what has the most impact on your maintenance performance)

How long does it take for your DR backup to perform the 1st phase ? (dr dump to disk)

 

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Hi @Laurent

our DR Backup takes about 4 minutes. 

 

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OK, and do you have 10 to 15 minutes where you have absolutely no running backups? (if you had auxcopys, you could easily suspend them before running the dbmaintenance job)

I would say that you could run this maintenance job during such a timeslot.

As you know, those are best practices, and Commvault must be very careful when providing docs an maintenance constraints, considering all kind of activity that would affect performance or behaviour of such operation. This said, if you are not using that much the scheduler during the timeslot you are targetting, it should perform without issue.

I would also recommend you to perform dbmaintenance on a regular basis, depending (again) on your environment and activity, but from monthly to weekly for recommended, and every quarter to every year for the full maintenance.

Would you run dbmaintenance using command line or from workflow ?

 

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Hello @Laurent

We have already the DB Maintenance Workflow in place but the CommServe DB now still shows a critical state. Therefore I would like to performe a DB Maintenance (Full via cli) and that's why I asked about the duration, because during the maintenance it is recommendet to disable the scheduler.

 

 

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OK, so you may review the duration of the previous dbmaintenance (even this one through your workflow). That should provide you with some pieces of information from start to completion, how long it took. Add a few extra minutes, and this should be the duration.

Honestly and again, IMHO if you don’t have an intense scheduler activity, and backup activity at this time, nor reports (because some can use intensively the database mostly for reading and could slowdown the process), then I would tell you to run it and not wait.

 

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Hello @Laurent 

Thank you very much. 
I will do the maintenance run tomorrow afternoon and think that with the information I have now received there should be no problems. 

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Thanks Thomas !

I’d really like to know how it behaved after your dbmaintenance, so your feedback will be very much appreciated 😉

Regards,

 

Laurent.

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Hello @Laurent

The maintenance was done within 8 minutes. The status is now no longer critical but on warning. I think this will improve if we perform the maintenance regularly. 

Kind Regards

Thomas

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