For backing up your Mac device, ISG has a storage service which integrates with the Time Machine backup software on macOS.
See https://isg.inf.ethz.ch/Main/ServicesBackupTimeMachine.
See https://isg.inf.ethz.ch/Main/ServicesBackupWindowsAndLinux.
If the standard quota you get is not large enough, you can request that ISG increase it by sending an email to support@inf.ethz.ch.