Technical Tip: Extend log disk FortiGate-VM running on VM ESXi

Description

This article describes how to extend log disk FortiGate running on VM ESXi.

Scope

FortiGate.

Solution

In the previous version, there was an option to add a new virtual disk, format it, and use it as another log disk. In the current version release, there is a behavior change.

When a new virtual disk is added to FortiGate VM and formatted, it will then be partitioned into 3 parts and can only be used as WAN Optimization Storage.

FortiGate-VM64 # execute disk list

Disk Virtual-Disk    ref:  16  30.0GiB    type: SSD [VMware Virtual disk] dev: /dev/sdb
  partition ref:  17  29.5GiB,  29.4GiB free  mounted: Y  label: LOGUSEDXE6E8088D dev: /dev/sdb1 start: 2048

Disk Virtual-Disk2   ref:  32  16.0GiB    type: SSD [VMware Virtual disk] dev: /dev/sdc
  partition ref:  33   4.5GiB,   4.4GiB free  mounted: Y  label: WANOPTXXB278EEE0 dev: /dev/sdc1 start: 2048
  partition ref:  34   4.6GiB,   4.6GiB free  mounted: N  label:  dev: /dev/sdc2 start: 9560064
  partition ref:  35   6.1GiB,   6.1GiB free  mounted: N  label:  dev: /dev/sdc3 start: 19120128

FortiGate-VM64 # c sys storage
FortiGate-VM64 (storage) # edit Virtual-Disk2
FortiGate-VM64 (Virtual-Disk2) # set usage
wanopt    Use hard disk for WAN Optimization.
FortiGate-VM64 (Virtual-Disk2) #

The only officially supported way to extend the log disk is by redeploying the VM with a larger disk size or a larger virtual disk size to the VM, but it is necessary to format the log disk.

execute formatlogdisk   

The above command is used to format or reinitialize the log storage disk on a FortiGate device to ensure the log system operates correctly after disk changes or corruption. 

Any other methods used to extend the log disk and issues caused as a consequence will not be supported by the Fortinet support team.

Related documents:

Logs are not being written to disk 

Technical Tip: Standard procedure to format a FortiGate Log Disk, log backup from disk