The system disk included with your Lightsail plan is your instance’s root device. If you terminate your instance, the system disk will be deleted as well. If you experience an instance failure, the system disk could be impacted. You also cannot detach your system disk or back it up separately from your instance. Data stored on an attached disk persists independently of the instance. Attached disks can be detached and moved between instances and can be backed up independently from an instance using disk snapshot. To protect your data, we recommend that you use your Lightsail instance’s system disk only for temporary data. For data requiring a higher level of durability, we recommend using attached disks and regularly backing up your disk using disk or instance snapshots.