Outcome: Reported Disk Utilisation % in Traverse is NOT inclusive of 5% disc space reservation for root.
Explanation:
In Linux based machine there is normally 5% disc space reservation for root.
It is observed that Disk Usage % reported by command 'df' will be different from that is reported by snmp.
- explanation of 'Use%' of this command: 'df -h'
[krish.majumder@bigair ~]$ sudo df -h
[sudo] password for krish.majumder:
Filesystem Size Used Avail Use% Mounted on
/dev/xvde 99G 75G 19G 80% /
Use% = (Size - Avail)/Size
80.80% = (99 - 19)/99
Note: Avail does not include 5% disc space reservation for root. This is evidenced by following calculation
(99 - 75 -19) = 5GB
- explanation of 'Use%' by snmp
Use% = Used / Size = 75 / 99 = 75.75% (Traverse will report this)
Further note: Why The Linux df Command Shows Lesser Free Disk Space?
http://www.walkernews.net/2011/01/22/why-the-linux-df-command-shows-lesser-free-disk-space/