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Troubleshooting

Fixes for refused connections, Permission denied (publickey), changed host keys and problems on the machine, plus booking questions and time zone mix-ups.

On this page

Connecting

Every machine is reached with ssh -p <port> renter@ssh.gputorent.com, where the port is your machine's own: shown on the reservation page while the reservation is live, and in the email we send when it goes live. The examples use 2211.

Connection refused or timed out

text
ssh: connect to host ssh.gputorent.com port 2211: Connection refused
ssh: connect to host ssh.gputorent.com port 2211: Operation timed out

Check, in order:

  1. Is the machine ready? At the start of the reservation the machine restarts once while it's prepared for you. Until the reservation page says Your machine is ready., it shows Preparing your machine… and connections are refused or time out. It usually takes a few minutes; refresh the page to check.
  2. Is it the right port? Each machine has its own port, and it's never 22. A command without -p, or with the port of an earlier reservation, reaches the wrong place. Copy the command from the reservation page. With scp the flag is a capital -P; with rsync, use -e "ssh -p 2211".
  3. Is your network blocking the port? Some office, hotel and public networks only let SSH out on port 22. Try another network, such as a phone hotspot. If the hotspot works, ask your network's administrator to allow outgoing connections to ssh.gputorent.com on your port.

If it still fails once the machine is ready, contact us with the reservation ID.

Permission denied (publickey)

text
renter@ssh.gputorent.com: Permission denied (publickey).

The machine didn't accept any key your SSH client offered. The machines accept keys only, so there's no password to fall back on. Check, in order:

  1. Is the user renter? Every machine's login is renter. Your own user name, root or any other name is refused. Without renter@ in the command, SSH uses the user name of your computer, so keep it in, or set User renter in your SSH config.

  2. Is it the right key? The machine is set up with the key you chose for this reservation; the reservation's page shows its name. Compare fingerprints — the one in SSH Keys in your dashboard and the one of your local key:

    bash
    ssh-keygen -lf ~/.ssh/id_ed25519.pub

  3. Is SSH offering it? If the key isn't the default file, name it with -i:

    bash
    ssh -p 2211 -i ~/.ssh/my_other_key renter@ssh.gputorent.com

    If your agent holds many keys, SSH may give up before reaching the right one ("Too many authentication failures"). Add -o IdentitiesOnly=yes with -i, or set it in your SSH config.

  4. Is the reservation live and the machine ready? Before the start, while the machine is being prepared, and after the end, your key isn't on the machine.

To see exactly which keys SSH tries, add -v:

bash
ssh -v -p 2211 renter@ssh.gputorent.com

Look for lines starting with Offering public key.

WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED

text
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

SSH remembers each machine's host key in ~/.ssh/known_hosts, one entry per [ssh.gputorent.com]:port, and warns when it changes, which could mean someone is intercepting the connection. A machine keeps its host key from one rental to the next, so you'll rarely see this; it happens when a machine has been reinstalled. If the port is exactly the one on your reservation page for a reservation that's live right now, remove the old entry for that port and connect again:

bash
ssh-keygen -R "[ssh.gputorent.com]:2211"

Keep the quotes and square brackets: they name the entry for that port. SSH then asks you to confirm the new fingerprint, which is normal.

If you're not sure why the key changed, don't connect: contact us first.

The connection drops when I'm idle

Add ServerAliveInterval 30 to your SSH config, and run long jobs inside tmux or screen, or with nohup, so they survive a dropped connection. See Connecting.

Preparing takes longer than a few minutes

Refresh the reservation page: it updates when the machine reports that it's ready. If it says that setting up is taking longer than it should, we've already been alerted. If it's still preparing ten minutes after the start, contact us with the reservation ID.

A server on the machine doesn't open in my browser

Only the SSH port reaches the machine from the internet, so an address such as http://ssh.gputorent.com:8888 never works. Open an SSH tunnel and use localhost on your computer instead:

bash
ssh -p 2211 -N -L 8888:localhost:8888 renter@ssh.gputorent.com

Then open http://localhost:8888, and keep the tunnel's window open. See Reaching a server on the machine and VS Code and Jupyter.

On the machine

The remote desktop won't connect

On a Mac Studio, Screen Sharing works only through an SSH tunnel; no VNC port is open to the internet.

  1. Is the tunnel open? Run it in its own window and leave it open while you use the desktop:

    bash
    ssh -p 2211 -N -L 5901:localhost:5900 renter@ssh.gputorent.com

  2. Are you connecting to 5901? Point your viewer at localhost:5901 (on a Mac, open vnc://localhost:5901), not 5900: your own Mac's Screen Sharing may already hold 5900.

  3. Is it this rental's password? It's different for every rental. Read it again with ssh -p 2211 renter@ssh.gputorent.com cat screen-sharing-password.txt, and log in as renter.

See Remote desktop on a Mac Studio.

My startup script didn't run

The script runs once, automatically, as renter, after the machine's restart at the start of the reservation. Look at its output and its state:

bash
cat ~/startup.log
cat /usr/local/var/renter-startup/state

The log starts with a line === Startup script started <time> ===. The state is one of:

  • waiting for first start: it hasn't started yet. Wait until the machine is ready.
  • running since …: it's still running. Follow it with tail -f ~/startup.log.
  • exited (code 0) at …: it finished. Another exit code means a command in it failed; the end of ~/startup.log shows which.
  • stopped: one-hour limit reached at …: it ran into the one-hour limit.
  • stopped: memory limit reached (DGX Spark only): it ran out of memory.

To run it again by hand:

bash
bash /usr/local/var/renter-startup/startup

See How startup scripts run.

sudo is not allowed

sudo refuses because renter is a standard account with no admin rights, by design. You can't change system settings, other accounts or the SSH configuration, and on a Mac Studio you can't brew install new formulae.

Install what you need in your home folder instead: Python packages in a virtual environment, uv, models and your own tools. On a DGX Spark, the docker command runs containers as you. If you need a system-level package, contact us: we can add it between rentals. See What's allowed on the machine.

The GPU isn't visible in a container

On a DGX Spark, give a container the GPU with --device nvidia.com/gpu=all, not --gpus all:

bash
docker run --rm --device nvidia.com/gpu=all nvcr.io/nvidia/cuda:13.0.0-base-ubuntu24.04 nvidia-smi

See DGX Spark environment.

Email sent from the machine doesn't arrive

Outbound email on port 25 is blocked. Send through a service that accepts authenticated email on port 587 or 465.

Booking

Today isn't bookable

That's expected. Daily reservations start at 00:00 UTC and must start at least an hour after you book, so today — which started at 00:00 UTC — can't be booked. Tomorrow can be booked until 23:00 UTC today. See Lead time, window and limits.

Every day in my range is green, but I can't select it

A reservation must fit on one machine, and no single machine is free for every day in your range. Try a shorter range, or other days. Availability explains why.

"You can hold at most 2 current or upcoming reservations on this plan"

You've reached the plan's concurrent limit. You can book again on that plan once one of your reservations has ended. See Concurrent limit.

"Those days were just taken"

Someone else booked the last free machine for those days a moment before you. The calendar has refreshed; pick other days.

"This is still not available in your country"

Sign-up and reservations are open in the EU, the United Kingdom, the United States, Canada, Australia and New Zealand. If you're in one of these and see this message — for example because you're travelling or on a VPN — contact us.

Time zones

My reservation seems to start on the wrong day

All times are UTC. Depending on where you are, 00:00 UTC can be the previous evening (in the Americas) or the next morning (in Asia and Oceania) in your local time. For example, a reservation starting Tue 22 Sep 00:00 UTC starts at 20:00 on Monday 21 September in New York during daylight saving time, and at 10:00 on Tuesday in Sydney. Check the start and end in UTC on the reservation page before you pay.

Convert a UTC time to your time

These print a UTC time in your computer's time zone. On Linux:

bash
date -d "2026-09-22 00:00 UTC"

On macOS:

bash
date -r "$(date -j -u -f "%Y-%m-%d %H:%M" "2026-09-22 00:00" +%s)"

Email

I didn't get the verification or reset email

Check your spam folder and wait a few minutes. Then request it again: Resend verification email, or Forgot password? on the login page. Still nothing? Contact us.