DMon is a lightweight terminal-side disk monitoring utility built for watching mounted filesystems grow in real time. Select a connected drive and immediately track capacity, used space, available storage, current growth rate, average growth, peak activity, elapsed monitoring time, and total filesystem expansion without recursively crawling every file on the disk.
DMon does not try to replace a full monitoring platform. It exists for the moment when you plug in a drive, start moving data, and want to know exactly what the filesystem is doing without opening another desktop application or waiting for a recursive directory scan.
DMon automatically discovers mounted real filesystems, filters out loop devices and virtual noise, identifies mount points, labels, filesystems, capacities, and transport information, then presents everything as a numbered terminal menu.
Once a drive is selected, DMon samples filesystem allocation directly and calculates current storage growth, average growth rate, peak activity, total session growth, usage percentage, and elapsed monitoring time.
Traditional du monitoring can become painfully expensive on large directory trees. DMon avoids that entire problem by reading filesystem-level allocation data instead of walking through every directory and file.
$ ./monitor.sh ============================================================ LIVE DRIVE MONITOR ============================================================ Device : /dev/sda1 Label : WOLF Connection : usb Filesystem : vfat Mount Point : /media/user/WOLF ------------------------------------------------------------ Capacity : 932GiB Used : 482GiB Available : 449GiB Usage : 51% ------------------------------------------------------------ Current : +82.3MiB/sec Average : +47.6MiB/sec Peak : 127.8MiB/sec Total Growth : +12.4GiB Elapsed : 00:07:31 Activity : [##################............] Ctrl+C : Return to drive selection
DMon is useful precisely because it stays out of the way. Keep it running beside a backup, archive extraction, disk image operation, large copy, media transfer, build process, or any workload where storage consumption matters.
Watch an external USB disk grow while data is being copied without hammering the same drive with repeated directory scans. Total Growth immediately tells you how much filesystem space has been consumed since the monitoring session began.
When something seems to be chewing through storage, DMon turns vague suspicion into visible numbers. Current and average growth rates make it much easier to see whether disk usage is stable, increasing slowly, or accelerating.
Plug in a USB drive, launch DMon, refresh the device list, choose the numbered filesystem, and monitor it. No configuration file, database, daemon, account, browser window, or telemetry service required.
Sometimes you do not need Grafana, Prometheus, an agent stack, six containers, and an observability manifesto. Sometimes you need Bash, findmnt, df, lsblk, arithmetic, and a blinking terminal next to whatever questionable thing you are currently doing to a disk.
A focused Linux utility packaged for the glorious tradition of downloading a small script, making it executable, and immediately finding a reason to leave it running all afternoon.
Real-time filesystem growth telemetry for Linux. Detect mounted drives, choose one from the terminal, and watch its storage behavior without recursively interrogating every innocent file on the device.