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SSH Keys — Troubleshooting

Cannot Download the Private Key After Creating a Keypair​

Symptom: The key creation dialog was closed before you clicked Download, or the downloaded file is corrupted.

Cause: The portal only allows you to download the private key once, immediately at creation time. After the dialog is closed, the private key is not stored on the system and cannot be recovered.

Resolution:

  1. Delete the key you just created from the SSH Keys list (the public key is saved but the private key is gone and the pair is unusable)
  2. Create a new keypair and click Download before closing the dialog
  3. Save the .pem file to the ~/.ssh/ directory and set the correct permissions: chmod 600 ~/.ssh/<key-name>.pem

Import Fails with "Invalid public key format"​

Symptom: You click Import but the system returns a format error.

Common causes:

  • You pasted the private key content instead of the public key
  • The public key is in PuTTY format (.ppk) — this format is not supported
  • The public key content has line breaks due to copy-pasting from an email or document

Resolution:

  1. Ensure you are pasting the content from the .pub file (for example id_ed25519.pub), not id_ed25519
  2. If you are using PuTTY, open PuTTYgen, load the key, select Conversions → Export OpenSSH key, then use the exported file
  3. Verify that the public key is a single continuous line — remove any extra line breaks in the textarea before submitting

SSH Connection Fails Despite Selecting the Correct Key When Creating the Instance​

Symptom: The Instance has started, the correct SSH Key was selected at creation time, but the ssh command returns Permission denied (publickey).

Common causes:

  • Using the wrong username — each image has a different default user (for example ubuntu, centos, cloud-user)
  • The private key file path or permissions are incorrect
  • The Instance had not finished starting when you attempted to connect

Resolution:

  1. Confirm the default username for the image you are using (refer to the image's documentation)
  2. Check the private key file permissions: chmod 600 ~/.ssh/<key-name>.pem
  3. Wait 60–90 seconds after the Instance transitions to Running status, then try again
  4. Try connecting with verbose output to see error details: ssh -vvv -i ~/.ssh/<key>.pem <user>@<ip>

SSH Key Was Deleted but the Instance Is Still Accessible With the Old Key​

Symptom: The key was deleted from the portal but the previous user can still SSH into the Instance using their private key.

Cause: This is the expected behavior. Deleting a key from the portal does not change the ~/.ssh/authorized_keys file inside the Instance.

Resolution:

  1. Connect to the Instance using a different key or via console access
  2. Open the ~/.ssh/authorized_keys file for the user whose access needs to be revoked (typically ubuntu, centos, or root)
  3. Delete the line containing the public key to be revoked
  4. Save the file — the change takes effect immediately, no restart required

SSH Key Field Does Not Appear When Creating an Instance​

Symptom: In the Instance creation form, there is no field or dropdown to select an SSH Key.

Cause: The current project has no SSH Keys saved.

Resolution:

  1. Exit the Instance creation form
  2. Go to Compute Engine → SSH Keys and create or import at least one key
  3. Return to create the Instance — the SSH Key field will appear with the key you just added