Technical Tip: FortiDDoS High Disk Usage on the /var/log Partition

It is important to determine which partition on the disk is full. The command should be used for review:

FortiDDoS# fnsysctl df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 484.2M 220.6M 263.7M 46% /
none 512.0M 91.9M 420.1M 18% /tmp
none 512.0M 14.5M 497.5M 3% /dev/shm
/dev/sdb1 370.3M 132.6M 218.1M 38% /data
/dev/sda1 62.9G 62.7G 0 100% /var/log
/dev/sdb3 945.2M 151.8M 744.5M 17% /home
/dev/sda3 369.1G 242.4G 107.9G 69% /var/intruguard
/dev/sda2 7.7G 32.8M 7.3G 0% /var/spool/crashlog

To resolve the issue of high disk usage on the /var/log partition, follow these steps:

• Enable shell access on the FortiDDoS:

config system global

    set shell-access enable

    set shell-username <username>

    set shell-password <password>

    set shell-timeout 30 

Notes:

The shell-timeout means the shell access will be disabled automatically after 30 minutes.

• Start a new SSH client connection using the credentials from the previous step.

• Then check the disk usage of the /var/log/mysql directory.

FortiDDoS # f sh

/# du -h -d 1 /var/log/mysql/

4.0K    /var/log/mysql/tmp

454.1M  /var/log/mysql/data

454.2M  /var/log/mysql/

• Run the command ls -l /var/log/mysql/ to list the files in the /var/log/mysql directory.

/# ls -l  /var/log/mysql/

drwxr-xr-x    6 root     0             4096 Mar 10 11:00 data

-rw-rw----    1 root     0             3551 Mar 10 11:00 error.log

drwxr-xr-x    2 root     0             4096 Mar  6 16:21 tmp

• Run the command echo "" > /var/log/mysql/error.log to clear the error.log file.

/# echo "" > /var/log/mysql/error.log

/# ls -l  /var/log/mysql/

drwxr-xr-x    6 root     0             4096 Mar 10 11:00 data

-rw-rw----    1 root     0             1 Mar 11 10:25 error.log

drwxr-xr-x    2 root     0             4096 Mar  6 16:21 tmp

• Run the command df -h to check the disk usage of the /var/log partition.