diff --git a/docs/admin/server-setup.md b/docs/admin/server-setup.md
index 5735b41..4432afd 100644
--- a/docs/admin/server-setup.md
+++ b/docs/admin/server-setup.md
@@ -189,8 +189,16 @@ sudo tee /etc/docker/daemon.json > /dev/null <<'EOF'
 }
 EOF
 
+# Configure containerd to use /data as well.
+# containerd runs as a separate daemon from Docker and has its own data root
+# (default: /var/lib/containerd). Without this, /var fills up with image snapshots.
+sudo mkdir -p /etc/containerd
+containerd config default | sudo tee /etc/containerd/config.toml > /dev/null
+sudo sed -i 's|^root = .*|root = "/data/containerd"|' /etc/containerd/config.toml
+
 # Verify
 docker --version
+sudo systemctl enable --now containerd
 sudo systemctl enable --now docker
 ```
 
diff --git a/docs/admin/troubleshooting.md b/docs/admin/troubleshooting.md
index 49b30aa..1efe4aa 100644
--- a/docs/admin/troubleshooting.md
+++ b/docs/admin/troubleshooting.md
@@ -857,6 +857,20 @@ du -sh /coder-workspaces/* | sort -h
 # Delete unused workspaces
 ```
 
+**/var partition full (containerd not in /data):**
+
+containerd runs as a daemon separate from Docker and has its own data root (`/var/lib/containerd` by default). If the server was set up without configuring containerd's root, image snapshots accumulate in `/var` rather than `/data`. Fix:
+
+```bash
+sudo systemctl stop docker containerd
+sudo mv /var/lib/containerd /data/containerd
+sudo sed -i 's|^root = .*|root = "/data/containerd"|' /etc/containerd/config.toml
+sudo systemctl start containerd && sudo systemctl start docker
+docker ps  # verify healthy
+```
+
+New server setups should configure containerd's root during initial setup — see `server-setup.md`.
+
 ## Getting Help
 
 ### Information to Collect