Troubleshooting — Odoo On-Premise

General Diagnostics

When something goes wrong, start with these commands to identify which component is the problem.

bash

# Check all key services at once
sudo systemctl status odoo postgresql nginx --no-pager

# View recent Odoo logs
journalctl -u odoo -n 100 --no-pager

# Check which processes are listening on which ports
sudo ss -tlnp

# Check Nginx configuration validity
sudo nginx -t

DNS Problems

DNS issues are the most common cause of a failed Let's Encrypt challenge and connection timeouts when first setting up the domain.

Symptom	Likely Cause	Resolution
Registrar parking page appears instead of Odoo	Registrar's default DNS records still active	Delete all default A and CNAME records from your registrar, then add your own A record pointing to the Oracle VM IP
Different devices resolve to different IP addresses	DNS cache not yet expired	Test with `dig @8.8.8.8 example.com` to bypass local cache. Wait for the TTL to expire.
HTTP 404 after pointing DNS correctly	Nginx `server_name` does not match the domain	Edit `/etc/nginx/sites-available/odoo` and ensure `server_name` matches your domain exactly, then `sudo nginx -t && sudo systemctl reload nginx`

bash

# Test with a specific DNS resolver to bypass cache
dig @8.8.8.8 +short example.com
dig @1.1.1.1 +short example.com

Nginx Problems

bash

sudo nginx -t
sudo systemctl status nginx --no-pager
sudo journalctl -u nginx -n 50 --no-pager
sudo cat /var/log/nginx/error.log | tail -50

Problem	Cause	Resolution
Default Nginx welcome page appears	Default site is still enabled	`sudo rm /etc/nginx/sites-enabled/default` and reload Nginx
502 Bad Gateway	Odoo is not running or is not listening on port 8069	Run `sudo systemctl status odoo` and check `sudo ss -tlnp \| grep 8069`
WebSocket errors / live chat not working	Missing `Upgrade` and `Connection` proxy headers	Verify the `/websocket` location block in the Nginx config includes `proxy_http_version 1.1` and the `Upgrade`/`Connection` headers
413 Request Entity Too Large on uploads	`client_max_body_size` is too low	Set `client_max_body_size 100M;` (or higher) in the Nginx server block

Enterprise Modules Missing

If Odoo starts but you only see Community modules in the app list, or the Enterprise features are absent, check the following.

Verify addons_path in /etc/odoo/odoo.conf includes the path to the Enterprise repository:
addons_path = /opt/odoo/community/addons,/opt/odoo/custom,/opt/odoo/enterprise
Confirm the Enterprise directory is not empty: ls /opt/odoo/enterprise/
Ensure both repositories are on the same branch: cd /opt/odoo/enterprise && git branch
Restart Odoo after any addons_path change: sudo systemctl restart odoo

Database created before Enterprise was configured

If the Odoo database was created before the Enterprise repository was added to addons_path, you may need to update the module list from the Odoo UI (Settings → Technical → Update Module List) or recreate the database.

HTTPS / Certbot Issues

Problem	Resolution
ACME challenge failed	Confirm DNS resolves to the VM and port 80 is reachable from the Internet. Run `curl -I http://example.com` from an external machine.
HTTPS connection times out	Open TCP 443 in the Oracle Security List and in iptables: `sudo iptables -I INPUT -p tcp --dport 443 -j ACCEPT`
Certificate not renewing automatically	Check `sudo systemctl status certbot.timer`. Run a dry-run: `sudo certbot renew --dry-run`
Too many failed attempts — rate limited	Wait at least 1 hour. Use `--staging` flag during testing: `sudo certbot --nginx --staging`
Browser still shows HTTP (no padlock)	Clear browser cache. Verify the HTTP→HTTPS redirect in the Nginx config: look for a `return 301 https://` directive.

Firewall Issues

bash

sudo iptables -L INPUT -n --line-numbers
sudo ss -tlnp

Problem	Resolution
Port 80 or 443 connection times out	Check both the Oracle Security List (cloud console) and iptables. Both must allow the port.
Rules disappear after reboot	Install `iptables-persistent` and run `sudo iptables-save \| sudo tee /etc/iptables/rules.v4`
Port 8069 accessible from Internet	Delete the ingress rule for TCP 8069 from the Oracle Security List. Ensure `http_interface = 127.0.0.1` in `odoo.conf`.

Keep port 8069 private at all times

Publicly exposing port 8069 bypasses Nginx, disables HTTPS encryption, and exposes Odoo directly to the Internet — this is a serious security risk.

Odoo Service Won't Start

bash

sudo systemctl status odoo --no-pager
journalctl -u odoo -n 100 --no-pager

Error in Logs	Cause	Resolution
`No such file or directory` for ExecStart	Incorrect path to Python or odoo-bin	Verify the paths: `ls /opt/odoo/venv/bin/python3` and `ls /opt/odoo/community/odoo-bin`
`Permission denied`	Files not owned by the `odoo` user	`sudo chown -R odoo:odoo /opt/odoo /etc/odoo`
`ModuleNotFoundError`	Python dependencies not installed in the venv, or wrong interpreter	Confirm ExecStart uses the venv Python, then `sudo -u odoo /opt/odoo/venv/bin/pip install -r /opt/odoo/community/requirements.txt`
PostgreSQL connection refused	PostgreSQL not running or wrong DB user	`sudo systemctl start postgresql` and verify the `odoo` role: `sudo -u postgres psql -c "\du odoo"`

Memory Limit Warnings

On small Oracle Cloud Free Tier instances (1 GB RAM), Odoo workers may be killed when they exceed the configured memory limits. This appears in the log as:

bash

tail -100 /opt/odoo/logs/odoo.log | grep -i "memory\|killed\|limit"

Symptoms: Odoo restarts unexpectedly, pages time out, or you see Worker exceeded memory limit in the logs.

Solutions:

Reduce active background tasks and installed apps to lower memory usage.

If more RAM is available, increase limits in odoo.conf:

bash

limit_memory_soft = 671088640   # 640 MB
limit_memory_hard = 1073741824  # 1 GB

For very small VMs, keep workers = 0 (single-threaded mode) to minimize overhead.

Monitor memory usage

Use free -h to check available RAM and htop or ps aux --sort=-%mem | head -10 to identify memory-heavy processes.