Disk & Filesystem Management (Du/Df/Lsblk/Fstrim)

Stop guessing why your disk space is still missing

🧩 The Challenge

You know the pain of deleting a massive log file to free up space, but df still insists the partition is 100% full. I’ve wasted hours staring at that, wondering if the filesystem is just straight-up lying to me.

💡 The Fix

Check if a deleted file is still being held open by a zombie process that refuses to let go of the handle. It’s almost always a runaway log-spewing application that didn’t catch a reload signal.

lsof +L1

⚙️ Why It Works

Since the kernel won’t actually reclaim the blocks until the process closes the file descriptor, identifying the specific process holding the dead file allows you to restart it and clear the space immediately.

🚀 Pro-Tip: If the PID is critical, just send it a SIGHUP instead of killing it; most daemons will reopen their log files correctly.

Linux Tips & Tricks | © ngelinux.com | 10/8/2026