How to free up space in my application pool?

Hello, everyone. Recently, I’ve been seeing the following message in my Alerts: "Space usage for pool ‘apps’ is 78%. Optimal pool performance requires used space to remain below 80%.“Optimal pool performance requires used space to remain below 80%.”.
I looked at the pool space and see what is taking up space.

sudo du -h --max-depth=1 /mnt/apps/ix-applications/k3s/agent/containerd
[sudo] password for admin:
1.0K /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.snapshotter.v1.fuse-overlayfs
14M /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.grpc.v1.cri
32G /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.content.v1.content
512 /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.runtime.v1.linux
512 /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.snapshotter.v1.btrfs
6.5K /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.snapshotter.v1.stargz
1.0K /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.snapshotter.v1.native
54G /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.snapshotter.v1.overlayfs
2.8M /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.metadata.v1.bolt
512 /mnt/apps/ix-applications/k3s/agent/containerd/lib
228K /mnt/apps/ix-applications/k3s/agent/containerd/io.containerd.runtime.v2.task
512 /mnt/apps/ix-applications/k3s/agent/containerd/tmpmounts
512 /mnt/apps/ix-applications/k3s/agent/containerd/bin
85G /mnt/apps/ix-applications/k3s/agent/containerd

Is there any way to free up space?

use the datasets page in the webui, find what’s using the space. you also don’t say how big the pool itself is, or if it has any other datasets besides ix-applications (and their descendants)

du will not show space that is used by old snapshots, however the datasets page in the ui shows space consumed by live data and previous snapshots. and there is a seperate webui page for snapshots that you should also pay a visit. \

also that error is an incredibly generic one that happens on any pool. IMO you can safely dismiss/ignore it and fill beyond if any of these apply:

  • you are using SSDs as fragmentation really doesn’t matter.
  • you are using HDDs and the data isn’t being constantly re-written. (media files, etc)
  • you are ok with a potential loss of performance on newly allocated data being slightly fragmented.

The pool itself is small at 120G. It contains only ix-applications and configuration files.
In webui, in the Dataset tab, 86G is occupied by ix-applications.


sudo du -h --max-depth=1 /mnt/apps/ix-applications
512 /mnt/apps/ix-applications/default_volumes
47M /mnt/apps/ix-applications/backups
1.1G /mnt/apps/ix-applications/catalogs
86G /mnt/apps/ix-applications/k3s
443M /mnt/apps/ix-applications/releases
88G /mnt/apps/ix-applications

If you don’t have a lot of snapshots with stale data retained, then perhaps consider growing the size of your pool.