A Start Job Is Running For /dev/mapper

So, I recently encountered an interesting issue while working on my computer. I received a message saying “A start job is running for /dev/mapper”. Initially, this caught me off guard and left me wondering what exactly was happening. After a bit of investigation and troubleshooting, I was able to understand the root cause of this message and find a solution. In this article, I’ll share my experience and provide you with some insights into what this message means and how you can address it.

Understanding the Message

When you see the message “A start job is running for /dev/mapper”, it typically indicates that the system is taking longer than expected to start a specific process related to a device mapper. The device mapper is a Linux kernel framework that provides a generic way to create and manage block devices. It is commonly used for creating and managing logical volumes in Linux.

Possible Causes

There can be several reasons why this message appears. One common cause is a misconfiguration or error in the configuration files related to the device mapper. Another possibility is that there might be an issue with the device itself or with the disk partitions being mapped.

Troubleshooting Steps

When facing this issue, it’s essential to follow a systematic approach to troubleshoot and resolve it. Here are some steps you can take:

  1. Check for Disk Errors: Run a disk check using the fsck command to identify and fix any potential errors on the disk. For example, you can run sudo fsck /dev/mapper/.
  2. Verify Configuration Files: Double-check the configuration files related to the device mapper, such as /etc/mapper/control or any other specific configuration files, for any errors or misconfigurations. Make sure the necessary drivers and modules are loaded correctly.
  3. Reboot the System: Sometimes, a simple reboot can resolve the issue if it was caused by a temporary glitch. Try restarting your system and see if the message disappears.
  4. Monitor Boot Process: During the boot process, press the ESC key to view the boot messages in more detail. Look for any error messages or warnings related to the device mapper. This information can help you identify the specific cause of the issue.
  5. Seek Community Support: If you are still unable to resolve the problem, it can be helpful to seek assistance from online forums, Linux user groups, or the respective distribution’s support channels. Other users may have encountered similar issues and can provide valuable insights or solutions.


Encountering the “A start job is running for /dev/mapper” message can be a bit disconcerting at first, but with a systematic approach and a bit of troubleshooting, you can usually resolve the issue. By understanding the role of the device mapper and following the steps outlined in this article, you can address the problem and get your system up and running smoothly again.

Remember, troubleshooting technical issues is a great opportunity to enhance your technical skills and deepen your understanding of the underlying systems. Embrace the challenge and keep exploring!