5 Tools for Monitoring Disk Activity in Linux - OpsDash
August 29, 2016 at 1:06:41 PM GMT+2 - permalink - - https://www.opsdash.com/blog/disk-monitoring-linux.html

https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats
October 16, 2014 at 3:13:57 PM GMT+2 - permalink - - https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats

Increase available disk space by decreasing the reserved blocks in extended filesytems ext2/3/4 using tune2fs | Linuxers
June 4, 2014 at 11:00:21 AM GMT+2 - permalink - - http://linuxers.org/quick-tips/increase-available-disk-space-decreasing-reserved-blocks-extended-filesytems-ext234-using-tune2fs

Best Free Disk Space Analyzer
April 7, 2013 at 4:13:51 PM GMT+2 - permalink - - http://www.techsupportalert.com/best-free-disk-space-analyzer.htm#SpaceSniffer