Systemd for voipmonitor service management

From VoIPmonitor.org


This guide covers managing the VoIPmonitor sensor service using systemd on modern Linux distributions.

⚠️ Warning: Always use systemctl commands. Do not use the legacy service command as systemd may lose track of the process state.

Unit File Configuration

Create /etc/systemd/system/voipmonitor.service: 

[Unit]
Description=VoIPmonitor sniffer
After=syslog.target network.target
# Add mysql.service only if DB is local (see Dependencies below)

[Service]
Type=forking
RemainAfterExit=yes
TimeoutSec=5min
KillMode=process
GuessMainPID=no
IgnoreSIGPIPE=no
SuccessExitStatus=5 6
ExecStart=/etc/init.d/voipmonitor start
ExecStop=/etc/init.d/voipmonitor stop
PrivateTmp=false

[Install]
WantedBy=multi-user.target

Dependencies

Scenario Add to [Unit] section
Local MySQL/MariaDB After=mysql.service
Napatech SmartNIC After=ntservice.service
Requires=ntservice.service
Wants=network-pre.target
Before=network-pre.target

Basic Commands

# After any unit file changes
systemctl daemon-reload

# Enable auto-start on boot
systemctl enable voipmonitor

# Start/Stop/Restart
systemctl start voipmonitor
systemctl stop voipmonitor
systemctl restart voipmonitor

# Check status
systemctl status voipmonitor

Watchdog Integration

When using the internal watchdog with systemd, configure it to restart via systemctl. Otherwise, systemd will incorrectly report the service as "failed" after a watchdog-triggered restart.

Add to /etc/voipmonitor.conf: 

watchdog = yes
watchdog_run_command = systemctl restart voipmonitor

Controlling Verbose Output

By default, VoIPmonitor outputs statistics to syslog every 10 seconds (controlled by -v 1 in the init.d script).

Option 1: Redirect to Dedicated Log (Recommended)

Add to /etc/rsyslog.conf: 

if $programname == 'voipmonitor' then /var/log/voipmonitor.log
& ~

Then: systemctl restart rsyslog

Option 2: Disable Statistics Entirely

⚠️ Warning: This removes valuable diagnostic metrics. Only use if necessary.

Edit /etc/init.d/voipmonitor, find the ARGS= line, and remove -v 1 (or v 1): 

# Before:
ARGS="-v 1 --config-file /etc/voipmonitor.conf"

# After:
ARGS="--config-file /etc/voipmonitor.conf"

Then: systemctl daemon-reload && systemctl restart voipmonitor

Troubleshooting

Unit File Syntax Errors

Symptom: "Assignment outside of section" or "control process exited with error code"

Fix: Check unit file for:

  • Missing section headers ([Unit], [Service], [Install])
  • Typos in directive names
  • Missing = signs

Emergency bypass: 

killall -9 voipmonitor
/etc/init.d/voipmonitor start
# Fix unit file, then:
systemctl daemon-reload && systemctl start voipmonitor

Multiple Instances Running (Duplicate Packets, Corrupted RRD)

Symptom: Duplicate SIP packets in GUI, broken RRD graphs, multiple voipmonitor processes

Cause: Both systemd unit and init.d wrapper trying to start VoIPmonitor

Fix: 

# 1. Kill all instances
sudo killall -9 voipmonitor

# 2. Disable init.d wrapper (keeps script but prevents auto-start)
sudo chmod -x /etc/init.d/voipmonitor

# 3. Delete corrupted RRD files
sudo rm -f /var/spool/voipmonitor/rrd/*

# 4. Start via systemd
sudo systemctl enable voipmonitor
sudo systemctl start voipmonitor

# 5. Verify single instance
ps aux | grep "[v]oipmonitor"

ℹ️ Note: The chmod -x disables the SysV compatibility service that systemd auto-generates from init.d scripts.

Connection Failures (Service Running but Not Connecting)

If systemctl status voipmonitor shows "active (running)" but logs show connection errors, the problem is not systemd-related. See Distributed Architecture Troubleshooting.

See Also

AI Summary for RAG

Summary: Guide for managing VoIPmonitor sensor with systemd. Create unit file at /etc/systemd/system/voipmonitor.service with Type=forking and RemainAfterExit=yes. Key dependencies: add After=mysql.service for local DB only, add After=ntservice.service with Requires=ntservice.service for Napatech cards. Always use systemctl commands (not legacy service). For watchdog integration, set watchdog_run_command = systemctl restart voipmonitor to prevent systemd from showing failed status after watchdog restarts. For multiple instance conflicts (duplicate packets, corrupted RRD), run chmod -x /etc/init.d/voipmonitor to disable the init.d wrapper, delete RRD files, and restart via systemd. For verbose log spam (every 10 seconds), either redirect via rsyslog or remove -v 1 from the init.d ARGS line.

Keywords: systemd, systemctl, voipmonitor.service, unit file, Type=forking, RemainAfterExit, After=mysql.service, Napatech, ntservice, daemon-reload, watchdog, watchdog_run_command, multiple instances, duplicate packets, corrupted RRD, chmod -x, verbose output, syslog spam, -v 1, rsyslog

Key Questions:

  • What is the recommended systemd unit file for VoIPmonitor?
  • How do I configure systemd dependencies for MySQL and Napatech?
  • How do I make VoIPmonitor start automatically on boot?
  • Why does systemd show service as failed after watchdog restart?
  • How do I fix multiple voipmonitor processes running (duplicate packets, corrupted RRD)?
  • How do I stop init.d and systemd from conflicting?
  • How do I disable or redirect the verbose statistics output to syslog?
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