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Applies to: LumaDock Cloud VPS • Ubuntu 20.04/22.04/24.04 • AlmaLinux/Rocky 8/9
If you see a 503 Service Unavailable error after installing CyberPanel, it usually means OpenLiteSpeed or CyberPanel is not running correctly, ports are blocked, or the VPS ran out of memory. Follow this step-by-step guide to fix it.
Quick Fix (Low RAM)
The most common cause is low memory. Add 2 GB swap 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:8090Step 1 — Check Services
systemctl status lsws lscpd --no-pager
systemctl restart lsws lscpdStep 2 — Verify Listening Ports
ss -lntp | grep -E ':(8090|7080)'
# Expect LISTEN on :8090 (CyberPanel) and :7080 (OLS admin)Step 3 — Open Firewall Ports
Ubuntu (ufw):
ufw allow 8090/tcp
ufw allow 7080/tcp
ufw allow 80,443/tcpAlmaLinux/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 --reloadStep 4 — Access Directly
If using Cloudflare or another proxy, test the origin directly:
https://SERVER_IP:8090
https://SERVER_IP:7080Step 5 — Check Logs
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-pagerStep 6 — Check for Out-of-Memory (OOM)
free -h
dmesg | grep -i -E 'out of memory|killed process' | tail -n 10If memory is too low, add swap (see Quick Fix).
Step 7 — Check SELinux (Alma/Rocky)
getenforce
setenforce 0
sed -i 's/^SELINUX=enforcing/SELINUX=permissive/' /etc/selinux/config
systemctl restart lsws lscpdStep 8 — Port Conflicts
lsof -i :8090 -PnIf another service is using port 8090, stop it or change its port.
Step 9 — Verify Listeners in OLS
Open https://SERVER_IP:7080 → Listeners → check *:8090 exists → restart:
systemctl restart lswsStep 10 — Repair CyberPanel
apt update && apt -y upgrade || dnf -y update
sh <(curl -s https://cyberpanel.net/install.sh)Select the Upgrade/Repair option if available.
After It Works
- CyberPanel:
https://SERVER_IP:8090 - OpenLiteSpeed Admin:
https://SERVER_IP:7080 - Ensure ports 80/443 are open for websites and SSL.
Tip: For stable operation, we recommend at least 2 GB RAM + 2 GB swap for CyberPanel. Remember, LumaDock VPS are unmanaged — firewall, OS, and control panels are customer-managed.
