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SLP - Excessive tape mounts

Hello,

I am using SLP for duplication to tape. There are about 50 consecutive duplication jobs every night. Each duplication job dismounts the tape after duplication. It leads to about 50 tape mounts, tape positionings before writing and tape dismounts every day.

I want to minimize the number of mounts to extend the service life of tape drives and tapes.

Is there any option to force NetBackup to keep the tape mounted between duplication jobs?

Thanks,

Lubos

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1 Solution

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Accepted Solution!

Re: SLP - Excessive tape mounts

I have checked with Veritas support. Unfortunately there is no option in NetBackup to prevent tape dismount within SLP duplication job.

View solution in original post

8 Replies

Re: SLP - Excessive tape mounts

for restores and things like database backups, NBU has the media unmount delay option.

Then in SLP world, those may not be applicable but there is RB_MPX_GROUP_UNLOAD_DELAY nbrb setting that might help

Re: SLP - Excessive tape mounts

hi @LubosDvorak 

Pls see:

https://www.veritas.com/support/en_US/doc/18716246-126559472-0/v84182756-126559472

I would recommend setting "MIN_SIZE_PER_DUPLICATION_JOB" to something like 50-100GB or even higher. Default value is 8GB and is waayyyy to low for my opinion.

Also take a look at the MAX_SIZE_PER_DUPLICATION_JOB at the same time, they go hand in hand.

Best Regards
Nicolai

Re: SLP - Excessive tape mounts

@Mouse Thanks, I tried the RB_MPX_GROUP_UNLOAD_DELAY setting you suggested but unfortunately it had no efect in SLP :(

Re: SLP - Excessive tape mounts

Hi @Nicolai, Thanks, I have already tuned it.

Re: SLP - Excessive tape mounts

hi @LubosDvorak 

Consider the number of volume groups and retentions.

It's more likely a SLP job will re-use a tape already mounted if retention and volume job is the same.  However if volume group and retention are different, Netbackup must unload/load a new tape in order to process the SLP's.

Just a hint :)

Update: also take a look at MAX_TIME_TIL_FORCE_SMALL_DUPLICATION_JOB

Re: SLP - Excessive tape mounts

hey

You can also consider to bump this parameter to a higher value:

 bpgetconfig |grep -i unmount
MEDIA_UNMOUNT_DELAY = 180

like let's say 10 minutes:

echo MEDIA_UNMOUNT_DELAY=600 |bpsetconfig

bpgetconfig|grep -i unmount
MEDIA_UNMOUNT_DELAY = 600

Hope one of these provided ideas will suit you.

Re: SLP - Excessive tape mounts

@LubosDvorakIs the SLP grouping enabled on the master server ? Worth trying to enable it. It will group SLP jobs of same priority and can help reducing in multiple SLP jobs.

Check out the SLP cheat sheet

https://www.veritas.com/support/en_US/article.100032502?profileURL=https%3A%2F%2Fvam-profile.veritas...

Check for SLP Parameter "SLP.DUPLICATION_GROUP_CRITERIA"

Hope it helps.

 

Accepted Solution!

Re: SLP - Excessive tape mounts

I have checked with Veritas support. Unfortunately there is no option in NetBackup to prevent tape dismount within SLP duplication job.

View solution in original post