---
title: "VAST Probe Troubleshooting"
slug: "vast-probe-troubleshooting"
description: "Troubleshoot VASTProbe issues, including launcher hangs, CPU incompatibility, and Docker container start failures, with step-by-step solutions."
updated: 2026-10-27T19:37:32Z
published: 2026-10-28T19:56:22Z
canonical: "docs.vastdata.com/vast-probe-troubleshooting"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# VAST Probe Troubleshooting

## Summary

In general, you can monitor the probe's behavior by watching the log file it generates and the standard output it writes to the console. Here we document common errors with the probe.

```plaintext
tail -f /mnt/probe/log/XXXX.log
```

## Launcher Hang

In rare cases, the probe completes its task successfully, but the Python launcher script hangs. If this happens, simply control-C the launcher if you are still attached to the terminal. Or use ps -ef to find the probe process and kill it.

## CPU Compatibility

Occasionally, the VAST Probe will launch and finish without scanning any files and may produce an error related to log files. When viewing logs, you may see:

```plaintext
probe terminated by signal: SIGILL
```

Check the CPU Compatibility:

```plaintext
cat /sys/devices/cpu/caps/pmu_name
```

Review the [VAST Probe Requirements](/kb/docs/vast-probe-requirements)

## CGroup Error

You may get the following error on older Linux builds:

```plaintext
Loading docker image
Starting probe docker container
783735ffbf1a722ebbcd43622476ea2364a8873dc2a6f95a4d006778636ed513
/usr/bin/docker-current: Error response from daemon: oci runtime error: container_linux.go:235: starting container process caused "process_linux.go:258: applying cgroup configuration for process caused \"Cannot set property TasksAccounting, or unknown property.\"".
Failed starting the probe
```

If you do, you need to update the systemd related packages. Here are the versions we use:

```plaintext
# rpm -qa |grep -i systemd
systemd-libs-219-67.el7_7.2.x86_64
systemd-sysv-219-67.el7_7.2.x86_64
systemd-219-67.el7_7.2.x86_64
oci-systemd-hook-0.2.0-1.git05e6923.el7_6.x86_64
```

## Privilege Error

When the container is launched, it may fail with this error message:

```plaintext
Starting probe docker container

docker: Error response from daemon: privileged mode is incompatible with user namespaces.  You must run the container in the host namespace when running privileged mode.
```

This message warns that your Docker environment will not allow Docker to run with elevated permissions. This is probably caused by a more secure Docker configuration, such as placing the following text into the /etc/docker/daemon.json file, which basically prevents a container from running as root with privileges:

```plaintext
{
 "userns-remap": "dockremap:dockremap"
}
```

The easiest way to address that is to hand-edit the VAST-provided probe_launcher.py and look for the 'docker run' line. It will look something like this:

```plaintext
 cmd = f'docker run --privileged -v {args.metadata_dir}:/probe_mnt/{args.metadata_dir} -v {args.output_dir}:/probe_mnt/{args.output_dir} '
```

Notice the --privileged. Remove it, save the file, and try again. If that doesn't fix the issue, we've found that removing the userns-remap line and restarting the Docker service can be more effective.

## Illegal Instruction

If the probe fails with a core dump and it shows an illegal instruction, you may be using an old CPU type that is not compatible with our compiled code. We require Intel Broadwell- or newer-compatible CPUs.

If you use GDB to debug the core, you can confirm by looking for something like this:

```plaintext

GDB output from core:
$ gdb -c core.97296 

For help, type "help".
Type "apropos word" to search for commands related to "word".
Core was generated by `/vast/install/probe/sim_estimator --similarity-function fast_hash_8 --split-win'.
Program terminated with signal SIGILL, Illegal instruction.
#0  0x00007fffec9deea7 in ?? ()
(gdb)
```