Symptoms vCenter Server Appliance root partition filled up 100%.
- Unable to log in through ssh with root and triggering "Access Denied" message.
- Unable to start vPostgresql likely due to unable to generate a single bit of write to postgresql.log and etc.
- Unable to start vCenter Appliance (obviously)
- In an attempt to change the root pass will exhibit the following errors. The following error of " passwd: Authentication token manipulation error." typically means filesystem is read-only. This might explain it that, since the / is filled up 100%, not a single bit can be written to it.
To solve this issue, simply login from the appliance console through GRUB.
https://kb.vmware.com/s/article/2147144?lang=en_US
Instead of at Step # 7, you can navigate around the system and look for big logs (du -h or ls -las) that might have caused the "/" to fill up 100% and remove it.
If all the filesystem growth is legitimate then the only option is to grow the / filesystem.
