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Jupyter

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What is the HTTPS security warning?

When accessing Jupyter, browsers show a security warning because we use self-signed certificates. To fix:
  1. Download and install our TLS certificate
  2. Windows/Linux: Can bypass by clicking Advanced → Proceed
  3. macOS: Must install certificate in Keychain Access
Installing the certificate removes the warning permanently.

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Why are Jupyter transfers slow?

Jupyter’s upload/download is not optimized for large files. Alternatives:
  • Use SCP/SFTP for large transfers
  • Use cloud storage (S3, GCS)
  • Use the Vast CLI copy commands
  • Zip multiple files before downloading

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How do I delete files in Jupyter to free space?

Jupyter moves deleted files to trash. To permanently delete: 
# In Jupyter terminal
rm -r ~/.local/share/Trash

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How do I run Colab notebooks?

  1. Select the PyTorch template with Jupyter enabled
  2. Start your instance
  3. Download the Colab notebook as .ipynb
  4. Upload to Jupyter
  5. Install any missing dependencies with pip install
For direct Colab connection, see our Colab guide.

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How do I download multiple files from Jupyter?

Jupyter Lab: Shift-click to select multiple files, right-click to download Jupyter Notebook: Must download individually or zip first: 
# Install zip
apt-get install -y zip

# Zip a directory
zip -r all_files.zip /path/to/files/

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Missing library or package errors?

Install dependencies in Jupyter terminal: 
# System packages
apt-get install -y PACKAGE_NAME

# Python packages  
pip install PACKAGE_NAME

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SSH Access

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How do I connect via SSH on Linux/Mac?

  1. Generate an SSH keypair:
ssh-keygen -t rsa
  1. Load the key and verify:
ssh-add
ssh-add -l
  1. Get your public key:
cat ~/.ssh/id_rsa.pub
  1. Copy the entire output (including ssh-rsa prefix and user@host suffix) to your Keys section
Example of complete SSH key: 
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAZBAQDdxWwxwN5Lz7ubkMrxM5FCHhVz... bob@velocity

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How do I connect via SSH from Windows?

Two options:
  1. Windows Subsystem for Linux (WSL) - Follow Linux/Mac instructions above
  2. PuTTY - See our Windows SSH Guide
Make sure to save the key in SSH RSA-2 format when using PuTTY.

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What is tmux and how do I use it?

We connect you to a tmux session by default for reliability. Common commands:
  • Create new terminal: Ctrl+b, c
  • Switch terminals: Ctrl+b, n
  • Split screen: Ctrl+b, % (vertical) or Ctrl+b, " (horizontal)
Search “tmux cheat sheet” for more commands.

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Can I disable tmux?

Not recommended (SSH can be unstable), but if needed, add to your onstart: 
touch ~/.no_auto_tmux

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SSH asks for a password - what’s wrong?

There is no SSH password - Vast.ai uses SSH key authentication only. If SSH asks for a password:
  • Your SSH key wasn’t added correctly to your account
  • You didn’t copy the entire public key (must include ssh-rsa prefix and user@host suffix)
  • Your SSH client is misconfigured
  • The private key isn’t loaded in your SSH agent
Double-check that you copied the complete public key to your Keys section.