What are the pool selection limitations for containers?

Apps and Virtualization
1

System info
TrueNAS SCALE 25.10.1
3 ZFS pools: fast storage, main storage, surveillance
Pool details / differences
fast storage: SSD raid10 array
main storage: HDD raid10 array
surveillance: single HDD (single-disk pool)
Pool creation history:
fast storage and main storage were created on SCALE 24.10 and later upgraded along with the system
surveillance was added later on SCALE 25.04
All three pools currently have the same/default properties (no special tuning). Each pool only contains datasets.
Important note (feature clarification)
I’m referring to Instances / Virtualization “Containers” (the experimental containers feature), not Apps.

Problem description
In the storage selection UI, I can only select one pool: surveillance.
The other two pools (fast storage, main storage) are never available for selection, even though they appear equivalent in terms of properties.
If I export/offline surveillance, then the UI shows no selectable pools at all.
After I import/add surveillance back, the UI again allows only surveillance (still no option to select the other pools).
What I checked / tried
Verified where the System Dataset is located (fast storage).
Verified where the Apps dataset is located (fast storage).
Checked via zfs list and deleted the hidden virtualization dataset (e.g. .ix-virt). After deletion, the hidden dataset is gone, but the Instances/Virtualization UI still only allows selecting surveillance.
Questions
What are the rules/limitations for which ZFS pools can be selected for Instances (experimental containers) storage in SCALE 25.10?
Could pool creation age/version history (24.10-upgraded pools vs a pool added in 25.04) affect eligibility?
Could the underlying drive type/layout (SSD array vs HDD array vs single-disk HDD pool) affect which pools are selectable?
Is there a recommended way to fully reset/uninitialize the Instances/Virtualization storage configuration so I can select a different pool (e.g. main storage)?

2

After renaming “surveillance” to “sur test” (a name with space), it became unavailable. And renaming “main storage” to “main, it became available. So we can assume that this is a bug that pool with a name include space will be unusable for containers.

2 Likes
3

Well done. Please report the bug, if not done already.
But for your own sake, avoid names with spaces or non-ASCII characters—anything which could cause issues on a command line.

1 Like
4

That’s a known limitation of incus IIRC. But generally spaces in names of datasets and pools should be avoided (save yourself some grief).