CyberPanel may show a 503 Service Unavailable error if OpenLiteSpeed is down, required ports are blocked, or the server runs out of memory. This guide walks you through the most reliable fixes.
Quick fix for low RAM
Many 503 errors occur when OpenLiteSpeed crashes due to insufficient memory. Create a 2 GB swap file and restart services:
fallocate -l 2G /swapfile \
chmod 600 /swapfile \
mkswap /swapfile \
swapon /swapfile \
echo '/swapfile none swap sw 0 0' >> /etc/fstab \
systemctl restart lsws lscpd
Then open:
https://SERVER_IP:8090
Step 1 — Check services
Verify OpenLiteSpeed and CyberPanel services:
systemctl status lsws lscpd --no-pager
systemctl restart lsws lscpd
Step 2 — Verify listening ports
Check that CyberPanel and OpenLiteSpeed admin ports are listening:
ss -lntp | grep -E ':(8090|7080)'
You should see LISTEN entries on port 8090 (CyberPanel) and 7080 (OpenLiteSpeed admin).
Step 3 — Open firewall ports
Ubuntu (UFW):
Allow port 8090
Allow port 7080
Allow HTTP and HTTPS
ufw allow 8090/tcp
ufw allow 7080/tcp
ufw allow 80,443/tcp
AlmaLinux/Rocky (firewalld):
firewall-cmd --permanent --add-port=8090/tcp \
firewall-cmd --permanent --add-port=7080/tcp \
firewall-cmd --permanent --add-service=http \
firewall-cmd --permanent --add-service=https \
firewall-cmd --reload
Step 4 — Access CyberPanel directly
If you use Cloudflare or another proxy, bypass it to test the origin server:
https://SERVER_IP:8090 https://SERVER_IP:7080
Step 5 — Check logs
Look for errors from OpenLiteSpeed or CyberPanel:
tail -n 200 /usr/local/lsws/logs/error.log \
tail -n 200 /var/log/cyberpanel/error.log \
journalctl -u lsws -u lscpd -n 200 --no-pager
Step 6 — Check for out-of-memory kills
free -h dmesg | grep -i -E 'out of memory|killed process' | tail -n 10
If memory is low, add swap (see Quick fix section).
Step 7 — Check SELinux (Alma/Rocky)
getenforce \
setenforce 0 \
sed -i 's/^SELINUX=enforcing/SELINUX=permissive/' /etc/selinux/config \
systemctl restart lsws lscpd
If CyberPanel works after this, SELinux was blocking processes.
Step 8 — Check for port conflicts
lsof -i :8090 -Pn
If another application is using port 8090, stop or reconfigure it.
Step 9 — Verify OpenLiteSpeed listeners
Open:
https://SERVER_IP:7080
Navigate to Listeners and confirm that *:8090 exists, then restart:
systemctl restart lsws
Step 10 — Repair CyberPanel
Update the OS, then run the CyberPanel installer’s repair option:
apt update && apt -y upgrade || dnf -y update
sh <(curl -s https://cyberpanel.net/install.sh)
Select the repair/upgrade option when prompted.
After it works
You should now be able to access:
CyberPanel:
https://SERVER_IP:8090OpenLiteSpeed Admin:
https://SERVER_IP:7080
Check that ports 80 and 443 are open if you plan to host websites with SSL.
A stable CyberPanel setup works best with at least 2 GB RAM + 2 GB swap. Remember that LumaDock VPS are unmanaged, which means OS, firewalls, and control panels are fully user-managed.