This document has not been formally reviewed for accuracy and is provided "as is" for your convenience.
Summary
Reference
Problem Description:
Differences between DF and DU Linux commands are not always clear, especially when working with SMAX.
Cause:
Not enough knowledge on Linux OS and how the disk volumes works.
Resolution:
DU command gets usage size based on file total size in the disk and DF gets the size at OS level, so for example:
Some file may be already deleted in the disk, but some process still collects its volume information, hence the output difference.
In order to fix that a disk de-fragmentation is needed.
Both commands should match after this.
Rebooting the system may or may not solve the issue, so it is safer to run the disk defragmentation.
Environment:
Tested on SMAX 2019.11.