With Greenbone Enterprise TRIAL, as well as Greenbone Community Edition (GCE), I ran into a problem where I could not log into the web interface after several tests. I just get a message:
The Greenbone Vulnerability Manager service is not responding. This could be due to system maintenance. Please try again later, check the system status, or contact your system administrator.
In order to get any information from the running system at all, it is necessary to become the root user. I achieved this as follows:
Open the Shell via the Support Menu and in the shell enter the following commands:
gos-state-manager set superuser enabled
gos-state-manager set superuserpassword y0ur-fuck1ng-c0mpleX-superus3r-p@ssw0rd
gos-state-manager save
Now you can log in directly in the console as the root user (for SSH it would probably be necessary to modify the configuration file /etc/ssh/sshd-config).
After a short investigation, I discovered that the GVMD service (systemctl status gvmd) is not running. This service cannot be started because the PostgreSQL database is not running either (systemctl status postgresql) and PostgreSQL cannot be started because it is always killed by the OOM killer (read from dmesg).
The free command showed that there was 4GB of RAM in the system, but this did not match my VMware setup, which is set to 16GB. Likewise, the number of cores in VMware was 8, while Linux only had 2.
It occurred to me that system resources could be limited directly by the kernel using the GRUB bootloader. Therefore, I looked into the file /etc/default/grub and I really found some limitations here:
GRUB_CMDLINE_LINUX = "$GRUB_CMDLINE_LINUX maxcpus=2"
GRUB_CMDLINE_LINUX = "$GRUB_CMDLINE_LINUX mem=5G"
So I commented out the mentioned lines, applied the changes to the system (update-grub) and restarted the machine. Now the machine has 8 cores and 16GB of RAM (as configured in VMware) and all services are running…