CompTIA Linux+ XK0-006 (V8) Practice Question

The lsof utility enumerates every open file descriptor that a process holds. Using the -p option limits the output to one PID, so lsof -p 4273 lists the exact path of each file, socket, or device the stalled job has open-quickly confirming whether it is blocked on the NFS mount.

Attaching strace might show no new information while the process is stuck inside an uninterruptible I/O syscall, so it often fails to reveal the resource. Sending kill -9 would attempt to terminate the job but does not deliver a signal to a task in the D state and forfeits the chance to collect data. Restarting the systemd unit stops and restarts the service but likewise yields no insight into the file causing the hang. Therefore, lsof -p 4273 is the most effective, non-intrusive diagnostic step.