Technical Tip: How to interpret the SNMP queries on disk usage and disk capacity

[duenlim]

Description	This article explains how FortiGate performs SNMP queries to check disk usage and capacity.
Scope	FortiGate SNMP.
Solution	The Fortigate MIB file comes with Disk Usage and Capacity OID numbers: fgSysDiskCapacity 1.3.6.1.4.1.12356.101.4.1.7 fgSysDiskUsage 1.3.6.1.4.1.12356.101.4.1.6 The SNMP response to the above query: -----SNMP query started----- 1: fgSysDiskUsage.0 138 -> 138MB is total usage -----SNMP query started----- 1: fgSysDiskCapacity.0 16125 -> 16125MB is total disk space Run the command 'dia sys logdisk usage' to check the total HD usage: dia sys logdisk usage Total HD usage: 144MB(138MiB)/16908MB(16125MiB) -> 16125MB is total disk space | 138MB is total usage Total HD logging space: 12680MB(12093MiB) -> Total free space on log disk  HD logging space usage for vdom "root": 5MB(5MiB)/12680MB(12093MiB) -> Used space on log disk Note: The total HD logging space is 12680MB(12.68GB). This is because FortiGate is using by design only 75% of the disk. For more information refer to Technical Tip: Hard disk utilization by the FortiGate