Multipass Uncontactable On MacOS: Bug & Fix

Nov 29, 2025 by Alex Johnson 44 views

Multipass Instance Uncontactable on macOS: Troubleshooting and Fixes

Experiencing issues with your Multipass instances on macOS, where they appear to be running but become uncontactable after a period of inactivity? This is a known problem, particularly on M1 Macs, and this article delves into the details of the bug, potential causes, and effective solutions to get your Multipass instances back on track. Let’s explore this frustrating issue and how to resolve it.

Understanding the Multipass Uncontactable Bug on macOS

If you're a macOS user leveraging Multipass for virtualization, you might encounter a frustrating issue: instances are listed as running but become uncontactable after being left idle for several hours. This problem, predominantly observed on M1 Macs, manifests when attempting to connect to an instance via shell, resulting in a hung state during stop or restart attempts, eventually leading to an 'unknown state'.

The root cause appears to be related to how Multipass interacts with the system's sleep functionality, though the exact mechanism remains unclear. While unmounting fuse+sshfs drives before leaving instances unattended has been attempted as a workaround, it hasn't consistently prevented the issue. This suggests a deeper problem within the Multipass service or its interaction with macOS's power management.

Key Symptoms of the Issue

Instances listed as Running in Multipass, but are uncontactable.
Attempts to shell, stop, or restart the instance hang indefinitely.
The instance state transitions to Unknown.
The issue often occurs after the Mac has been sleeping for several hours.

Technical Details

This issue has been reported on macOS Sequoia running on M1 Macs, specifically with Multipass versions 1.16.1+mac and multipassd 1.16.1+mac. Users have noted that the problem arises after leaving their Macs in sleep mode for extended periods, although it's not definitively confirmed if sleep mode is the sole trigger. To further investigate the problem, it is important to gather detailed logs. Examining the multipassd.log file can reveal error messages or unusual activity preceding the uncontactable state, providing clues about the underlying cause. Analyzing these logs often requires a deeper understanding of Multipass internals and system-level interactions.

Diagnosing the Problem

Before diving into solutions, it's crucial to confirm you're facing the specific bug discussed here. Key indicators include:

Environment: macOS (especially on M1 Macs).
Multipass State: Instances marked as "Running" but inaccessible.
Error Symptoms: Shell connection failures, unresponsive stop/restart commands.

To diagnose, you can use the following Multipass commands:

multipass list: This command will show the status of all your Multipass instances. Check if any instances are listed as "Running" but you cannot connect to them.
multipass info <instance-name>: Replace <instance-name> with the name of your instance. This command provides detailed information about the instance, including its state, IP address, and resource usage. If the state is "Running" but you still cannot connect, it might indicate the issue.
multipass shell <instance-name>: Try to connect to the instance using this command. If it hangs or fails to connect, it further confirms the problem.

In addition to these commands, reviewing the Multipass logs can provide valuable insights. The logs are typically located in /var/log/multipassd.log or a similar location, depending on your system configuration. Examining the logs for error messages or unusual activity around the time the instance became uncontactable can help pinpoint the root cause.

Quick Fix: Restarting the Multipass Service

The most reliable immediate solution is restarting the Multipass service. This can be done via the following commands in your terminal:

$ sudo launchctl unload /Library/LaunchDaemons/com.canonical.multipassd.plist
$ sudo launchctl load /Library/LaunchDaemons/com.canonical.multipassd.plist

These commands effectively stop and then restart the Multipass daemon, which manages the instances. This action often restores connectivity to the affected instances, allowing you to resume your work. Keep in mind that restarting the service will temporarily interrupt all running Multipass instances, so it's best to do this when you're not actively using them. After restarting, you may need to reconnect to your instances using multipass shell <instance-name>.

Step-by-Step Guide to Restart Multipass Service

Open Terminal: You can find Terminal in the /Applications/Utilities folder or by searching for it using Spotlight.
Unload Multipass Daemon: Enter the following command and press Enter:
```
sudo launchctl unload /Library/LaunchDaemons/com.canonical.multipassd.plist
```
You'll be prompted for your administrator password. Enter it and press Enter. This command stops the Multipass daemon.
Load Multipass Daemon: Enter the following command and press Enter:
```
sudo launchctl load /Library/LaunchDaemons/com.canonical.multipassd.plist
```
This command starts the Multipass daemon.
Verify Status: You can check the status of the Multipass service by running:
```
launchctl list | grep com.canonical.multipassd
```
If the service is running, you should see an entry with the process ID and the service name.

After completing these steps, your Multipass instances should be accessible again. If the issue persists, you may need to investigate further or consider more permanent solutions.

Potential Root Causes and Long-Term Solutions

While restarting the service provides immediate relief, it's essential to understand the underlying causes to prevent recurrence. The issue may stem from:

macOS Sleep Issues: The interaction between macOS's sleep function and Multipass's virtualization environment might be problematic.
Resource Management: Inadequate resource allocation or contention could lead to instance instability.
Networking Glitches: Problems with network interfaces or Multipass's internal networking configuration might cause connectivity issues.

For long-term solutions, consider the following:

Multipass Updates: Keep Multipass updated to the latest version. Updates often include bug fixes and performance improvements that can address known issues.
macOS Updates: Ensure your macOS is also up to date. System updates can resolve compatibility issues and improve overall system stability.
Power Management Settings: Adjust your Mac's power management settings. You might try preventing the system from sleeping or configuring specific sleep settings to see if it resolves the issue.
Resource Allocation: Review the resource allocation for your Multipass instances. Ensure they have enough CPU and memory allocated to function properly. If you have multiple instances running, consider distributing resources evenly to prevent any one instance from starving others.
Networking Configuration: Check your network configuration. Ensure that Multipass is using the correct network interface and that there are no conflicts with other virtual machines or network services.
Bug Reporting: If the issue persists, consider reporting the bug to the Multipass developers. Provide detailed information about your system configuration, steps to reproduce the issue, and any relevant logs. This helps the developers identify and fix the problem in future releases.

Advanced Troubleshooting Steps

If the basic solutions don't resolve the issue, you might need to delve into more advanced troubleshooting steps. These steps often involve examining system logs, debugging Multipass processes, and potentially modifying system configurations.

Examining System Logs

In addition to the Multipass logs, system logs can provide valuable information about what's happening on your Mac. Use the Console application (found in /Applications/Utilities) to view system logs. Filter the logs by processes related to Multipass (e.g., multipassd, qemu) to identify any errors or warnings that might be contributing to the problem.

Debugging Multipass Processes

If you're comfortable with command-line debugging tools, you can attach a debugger to the multipassd process to inspect its state and identify potential issues. This requires advanced technical knowledge and is typically done by developers or experienced system administrators.

Modifying System Configurations

In some cases, you might need to modify system configurations to resolve the issue. This could involve adjusting network settings, power management settings, or other system-level parameters. However, be cautious when making changes to system configurations, as incorrect modifications can lead to further problems. Always back up your system before making significant changes.

Preventative Measures and Best Practices

To minimize the chances of encountering this issue, consider these preventative measures:

Regular Backups: Regularly back up your Multipass instances. This ensures you can quickly restore your environment if something goes wrong.
Graceful Shutdowns: When possible, gracefully shut down your instances before putting your Mac to sleep. This can help prevent data corruption and other issues.
Resource Monitoring: Monitor the resource usage of your instances. Ensure they're not consuming excessive CPU or memory, which can lead to instability.
Stay Informed: Stay informed about known issues and workarounds. Check the Multipass GitHub repository and community forums for updates and discussions.

Conclusion

While the Multipass uncontactable instance issue on macOS can be disruptive, understanding the potential causes and solutions can help you effectively manage and resolve the problem. By applying the troubleshooting steps outlined in this article, you can restore connectivity to your instances and prevent future occurrences. Remember to keep your Multipass and macOS installations updated, monitor resource usage, and consider reporting any persistent issues to the developers.

For additional information and support, consider visiting the Multipass Documentation.