vps

BitTorrent and private-tracker clients benefit from accepting inbound connections, but CGNAT prevents that. Your ISP places multiple subscribers behind one public IPv4 address, so there is no inbound mapping for the home server. Port forwarding on the home router does not help because the relevant NAT is upstream at the ISP.

A VPS with a public address and a WireGuard tunnel can relay the traffic. It receives torrent connections on a port range and forwards them through the tunnel to the home server. To peers, the home server is then reachable at the VPS's public address.

The Linux OOM killer runs when the kernel can no longer reclaim memory. If anonymous memory exceeds RAM and has nowhere to go, the kernel scores processes and kills the one with the highest score. On a small VPS, that can be the application, database, or build job you meant to keep alive. A low-priority daemon with a large RSS can lose, but so can one large process when there is no swap.

Swap gives anonymous pages backing storage under memory pressure. The kernel can evict those pages instead of killing the owning process, at the cost of latency when it reads them back. On a VPS, that delay is often preferable to losing the process.

I run two inexpensive OranMe VPS instances: one has 0.1 CPU and 128MB RAM, the other 0.5 CPU and 512MB. They are only suitable for light self-hosted work, so I installed Debian without a desktop environment.

The 0.1 CPU box kept shutting down. In the OranMe control panel, its CPU usage hit the limit shortly before each crash. That looked like the provider's abuse protection killing the VM. /var/log/system.log showed that the spikes matched apt's periodic tasks.