Space guarantee VS space available

ESSENTIAL — Thu, 05 Jun 2025 06:21:16 GMT

Hello all ,

I'm totally newbie so sorry for my not-that-smart questions. I will write You case-study of what I was doing:

First I created an aggr containings 6 1g disks with raid-dp:

filer1> aggr create aggr1 6

Creation of an aggregate with 6 disks has completed.

filer1> aggr show_space aggr1 -m

Aggregate 'aggr1'

Total space WAFL reserve Snap reserve Usable space BSR NVLOG A-SIS Smtape

4000MB 400MB 0MB 3600MB 0MB 0MB 0MB

This aggregate does not contain any volumes

Aggregate Allocated Used Avail

Total space 0MB 0MB 3599MB

Snap reserve 0MB 0MB 0MB

WAFL reserve 400MB 0MB 399MB

2. Create a volume and set it to 3g

filer1> vol create vol1 aggr1 3g

Creation of volume 'vol1' with size 3g on containing aggregate

'aggr1' has completed.

filer1> aggr show_space aggr1 -m

Aggregate 'aggr1'

Total space WAFL reserve Snap reserve Usable space BSR NVLOG A-SIS Smtape

4000MB 400MB 0MB 3600MB 0MB 0MB 0MB

Space allocated to volumes in the aggregate

Volume Allocated Used Guarantee

vol1 3089MB 0MB volume

[...]

And at this moment I exported vol1 as a cifs share and mount it to my windows. And I see:

2,84 GB free of 2,84 GB which is correct - the 5% difference because of snapshot reserve - right?

Than I wanted to turn off space guarantee with command:

filer1> vol options vol1 guarantee none

because space guarantee is turned off, even though my aggr has only about 4g space I can add to vol1 500g

filer1> vol size vol1 +500g

vol size: Flexible volume 'vol1' size set to 503g.

This volume is cifs share to windows, and windows now shows me:

737 MB free of 477 GB

First question: How windows "knows" that not all of 477 GB is available... Is there a way to 'hide' from a end-user the real size of space that is available? Of course I did not set any quotas at this point.

Second question: Why the free space "shrinked to" 737 MB even though my aggr has 4GB size (the volume is empty).

and now more interesting stuff, I changed the volume back to 3g:

filer1> vol size vol1 -500g

vol size: Flexible volume 'vol1' size set to 3g.

Third question: Why windows shows me that my cifs share has 737 MB free of 2,84 GB ? What's going on with (about) 2 GB used space right now ?

I'm not able to set the vol quarantee to "volume" unless I shink my volume to 737 MB (or less).

filer1> vol size vol1 500m

vol size: Flexible volume 'vol1' size set to 500m.

filer1> vol options vol1 guarantee volume

and now:

filer1> aggr show_space aggr1 -m

Aggregate 'aggr1'

Total space WAFL reserve Snap reserve Usable space BSR NVLOG A-SIS Smtape

4000MB 400MB 0MB 3600MB 0MB 0MB 0MB

Space allocated to volumes in the aggregate

Volume Allocated Used Guarantee

vol1 3361MB 1MB volume

Aggregate Allocated Used Avail

Total space 3361MB 1MB 238MB

Snap reserve 0MB 0MB 0MB

WAFL reserve 400MB 2MB 397MB

why my vol1 has alocated 3361MB even though the volume size is 500m ? Is this normal behaviour or is it some kind of simulator bug?

Once again, I'm just a newbie, so please don't laugh at me if I don't understand some general basic stuff

Re: Space guarantee VS space available

VKALVEMULA — Thu, 23 Aug 2012 16:12:55 GMT

did you unistall and reinstall the software

and do the same stuff.

Re: Space guarantee VS space available

ESSENTIAL — Fri, 24 Aug 2012 07:52:40 GMT

thanks for the replay

I did a mistake in a first "part" of my post - the aggr created from 4 disks, not 6. But it does not matter

As far as I look into this issue I think it's how it's supposed to be.

I guess making volume larger - space for hm wafl? inods? was extended. And when I make vol smaller again - it just does not change the space reservation for inods?

But I would be really happy if someone could confirm that.

aonther example without thin provisioning:

filer1> vol create proba aggr1 20m

Creation of volume 'proba' with size 20m on containing aggregate

filer1> aggr show_space -m aggr1

VOLUME Allocated Used Guarantee

[...]proba 20MB 0MB volume

filer1>vol size proba aggr1 +1g

vol size: Flexible volume 'proba' size set to 1044m.

filer1> vol size proba -1g

vol size: Flexible volume 'proba' size set to 20m.

filer1> aggr show_space -m aggr1

VOLUME Allocated Used Guarantee

[...]proba 25MB 0MB volume

Where did 5 mb go ?:)

topic Re: Space guarantee VS space available in Simulator Discussions

Space guarantee VS space available

Re: Space guarantee VS space available

Re: Space guarantee VS space available