DreamCompute instances are created with a specified SSH Key pair which is used for gaining initial access. Here are a couple recommendations to prevent getting locked out of your DreamCompute instance.
Set a password for the default user
By default the ssh configuration file (/etc/ssh/sshd_config) does not allow for password authentication, so it's advised to set a strong password for your default user. Should you become locked out and not able to log in with the Key Pair, you can still log in using the DreamCompute dashboard. Once logged in, you can sudo to fix possible issues, set a new ssh key, and so on. View the following article for instructions on how to create a password for your default user:
Create your own users
It is not required to use the default username provided by the operating system. Once logged in with the default user, additional users can be created.
The default user and its SSH Key can be a backup access option, rather than the only login option.
Being an unmanaged service, the customer is responsible for their own data. If there are important data, configuration files, and so on that you wish to keep safe, please consider installing an S3 CLI client like s3cmd, awscli, or another tool from the DreamObjects applications page.