deallocvt - Linux


deallocvt is a command used to deallocate a virtual terminal (VT), which is a text-based console on Linux systems. It is primarily used to reclaim memory and system resources when a VT is no longer needed, freeing up space for other processes or tasks.


deallocvt [options] [vt number]


| Option | Description | Default |
| -f | Force deallocation even if processes are still attached to the VT | No |


  • Deallocate VT 5:
deallocvt 5
  • Force deallocate VT 4:
deallocvt -f 4

Common Issues

  • Error: VT is not attached to any processes: Ensure that the VT is not being actively used by any running processes. Close all programs and applications that may be connected to the VT before deallocation.
  • Permission denied: Verify that you have sufficient permissions to deallocate the VT. Typically, only root users can deallocate VTs.


deallocvt can be combined with other commands to manage VTs effectively. For instance:

  • Free all unused VTs:
ls /dev/tty[0-9]* | grep 'console' | xargs -r deallocvt

Related Commands

  • chvt: Change to a specified VT.
  • fgconsole: Bring the specified VT to the foreground.
  • vlock: Lock the keyboard and screen of a VT.