Fixing a 502 Bad Gateway on VMware SDDC Manager by Freeing Up Disk Space (Log Rotation Issue)

Issue

When the root partition of your SDDC Manager VM fills up, critical services — including the web UI — fail to start properly. This often results in browser errors like:

					502 Bad Gateway – nginx

Understanding the Cause

Before diving into updates or configuration changes, the first step is to confirm if disk space is the root cause.

1. SSH Into the SDDC Manager
ssh vcf@<SDDC-Manager-IP>
su root

2. Check Disk Usage
Once logged in as root, check if any partitions, especially /, are at or near 100% capacity:

					df -h

If the root volume (e.g., /dev/mapper/vg_system_lv_root) is full, you’re likely dealing with a large log or journal file.

Solution

Clear Large Log Files

To identify oversized logs in /var/log, run:

					du -ah /var/log | sort -rh | head -n 20

This command shows the largest files for example, messages.1, audit.log, or auth.log. If they are unusually large, log rotation may have failed.

Fix Log Rotation

Now the files have been reset, you need to confirm logrotation configuration is correct, and restart the logrotation service, by using the following command:

					logrotate -f /etc/logrotate.conf

Now reboot the SDDC Manager vm with the following command:

					reboot