How to Fix AIX 7.1 'umount: 1831-015 16 Error - The Requested Resource is Busy'

If you're encountering the 'umount: 1831-015 16 error while unmounting 198.1.1.24:/mnt/backup - The requested resource is busy' message on your AIX 7.1 system, it means the specified network filesystem is currently in use. This guide will walk you through the steps to identify and resolve this issue.

Understanding the Error

The error message indicates that processes or services are actively using the filesystem you're trying to unmount (198.1.1.24:/mnt/backup). Attempting to force the unmount could lead to data loss or corruption.

Troubleshooting Steps

1. Identify Processes Using the Resource:

   • Use the fuser command to list processes accessing the filesystem: fuser -cu /mnt/backup
   • Alternatively, use the lsof command: lsof /mnt/backup
   • Both commands will display the Process IDs (PIDs) of the processes using the resource.

2. Terminate the Processes:

   • Once you have the PIDs, use the kill command to stop them. For example, to forcefully terminate a process, use: kill -9 <PID> (replace <PID> with the actual process ID).
   • Caution: Forcefully terminating processes might lead to data loss. Consider notifying users and saving any work before proceeding.

3. Retry Unmounting:

   • After terminating the processes, attempt to unmount the filesystem again using: umount /mnt/backup

Persistent Issues

If the error persists, it could be due to:

• Network Connectivity: Ensure stable network connectivity between your AIX server and the system hosting the filesystem (198.1.1.24).
• File Locks: Check for any remaining file locks on the filesystem. You can use the lsof command with the +D option to list open files and directories recursively within the mount point.
• Other System Services: Investigate if any system services are using the filesystem and stop them if possible.

If you're unable to resolve the issue, contact your system administrator for further assistance.