Recovering 9G of usable space from vol0

[bepresseditor]

On a space restricted filer, I can't help but notice that 9G of usable (post-tax) space is dedicated to vol0, which contains less than .5G of actual data.  I tried an end-run around this:

Marie-NetApp> vol size vol0 -1g

vol size: Volume 'vol1' cannot be resized below 9 GB on this appliance because it is the root volume.

Marie-NetApp> vol copy start vol0 vol1

Marie-NetApp> vol size vol1 1g

vol size: Flexible volume 'vol1' size set to 1g.

Marie-NetApp> vol options vol1 root

vol options: Volume 'vol1' cannot become the root volume after a reboot because it must be at least 9 GB on this appliance.

Obviously this was a spectacular failure.

As a workaround, would there be any downside to expanding vol0 to take the entire aggregate, and then simply storing user data directories in it?  In this particular case this is an FAS2020 with X268_SGLXY750SSX AQJZ 635.5GB 512B/sect drives.  But the identical space reservation appears on other versions of Data OnTAP with other drive geometries.  Is it just 9G no matter what?

[evilensky · Accepted solution]

From the System Administration Guide on root volume recommendations (7.2.7):

Size requirement for root FlexVol volumes

The root volume must have enough space to contain system files, log files, and core files. If a system problem occurs, these files are needed to provide technical support.
In contrast with traditional volumes, it is possible to create a FlexVol volume that is too small to be used as the root volume. Data ONTAP prevents you from setting the root option on a FlexVol volume that is smaller than the minimum root volume size for your storage system model, and prevents you from resizing the root volume below the minimum allowed size.
A root FlexVol volume must have a space guarantee of volume. Data ONTAP prevents you from setting the root option on a FlexVol volume that does not have a space guarantee ofvolume, and prevents you from changing the space guarantee for the root volume.
The minimum size for a root FlexVol volume depends on your storage system model. The following table lists the minimum allowed size for root volumes.




Storage system model
Minimum root FlexVol volume size




FAS250
9 GB


FAS270
10 GB


FAS2020
10 GB


FAS2050
12 GB


FAS920
12 GB


FAS940
14 GB


FAS960
19 GB


FAS980
23 GB


FAS3020
12 GB


FAS3040
16 GB


FAS3050
16 GB


FAS3070
23 GB


FAS3140
16 GB


FAS3170
37 GB


FAS6030
37 GB


FAS6040
37 GB


FAS6070
69 GB


FAS6080
69 GB


R200
19 GB


SA200
12 GB


SA300
23 GB


SA600
69 GB

• It is recommended that you avoid storing user data in the root volume, regardless of the type of volume used for the root volume.