topic LUN resrevation and LUN move in ONTAP Discussions

LUN resrevation and LUN move

nicholas4704 — Wed, 04 Jun 2025 23:46:09 GMT

I have a question from NSO-506 practice exam available from netapp.com

https://learningcenter.netapp.com/content/public/production/extra/certification/NS0-506-PRACTICE/index.html

You have an empty 50Gb space reserved lun1 in vol1 in aggr1. You run a "lun move" command to move lun1 to vol2 in aggr2.
You notice that the 50GB resrved LUN space is not reflected in the "used%" column for aggr2 in "storage aggregate" show output.
Why is the reserved LUN space missing from aggr2

1-The vol2 fractional reserve is set to 0
2-The vol2 fractional reserve is set to 100
3-The vol2 space guarantee is set to none
4-The vol2 space guarantee is set to volume

I think that the correct answer is Nr 4. If destination volume has already reserved space from aggregate (guarantee=volume) then when you move lun to that volume, aggregate space free space is not reduced, cause it was reduced when volume was created already.

BUT

The correct answer by this website is nr 3, i.e. gurantee set to none.

I tried to reproduce this on my 8.3 system and looks like both answers are correct. I can't understand why lun reserved size is not reflected in aggr2 after lun move if guarantee was set to none? I checked, it does show that volume used size increased after move command, but no used% increase in aggregate.

Why?

Nick

Re: LUN resrevation and LUN move

aborzenkov — Thu, 16 Jul 2015 20:10:37 GMT

Even though 4 may be correct, it is too trivial to be interesting. 3 demonstrates that LUN space reservation is not honored by aggregate if volume guarantee is set to none (and LUN is empty in this case).

Every test I took had some questions where you simply need to know what is expected to be correct answer. So even if you have good experience attending training makes sense - test questions are usually aligned with training materials.

Re: LUN resrevation and LUN move

nicholas4704 — Fri, 17 Jul 2015 06:28:04 GMT

Ok, I see. You are right

This KB explains that

https://kb.netapp.com/support/index?page=content&id=2011404&locale=en_US