When you’re using Proxmox for free without any subscription you may see bash TASK ERROR: command 'apt-get update' failed: exit code 100 The issue here is that by default Proxmox is using subscription only repos, you can remove this “error” by either getting a subscription (duh), or change the repo to pve-no-subscription. This repo is not as stable as the subscription one they claim, but for a home server it should be enough.