Protecting data during different connectivity states

A method of backing up a primary storage device for a computing device, the method comprising:

• executing a backup engine that backs files on the primary storage device up to a backup device, the primary storage device comprising a cache, and for a backup comprising one or more backup cycles the backup engine:
• tracks backup statuses of respective target files on the primary storage as either incomplete, in-progress, or complete;
• each time there is a determination that the backup device has become available, responds by:
• initiating copying of any target files in the cache to the backup device and changing corresponding statuses to indicate completion as such target files finish being copied to the backup device, and by initiating copying target files from the primary storage device to the backup device and changing corresponding statuses to indicate completion as such target files finish being copied to the backup device;
• and
• each time there is a determination that the backup device has become unavailable:
• stopping copying any target files in the cache to the backup device and leaving the corresponding statuses indicating in-progress, stopping copying target files from the primary storage device to the backup device, and initiating copying target files from the primary storage device to the cache and changing the corresponding statuses to indicate in-progress.

A method of performing backing up a primary storage device of a computing device, the method comprising:

• monitoring for availability of a backup device during a first and second backup cycle;
• during the first backup cycle, when the backup device becomes unavailable, diverting first backup copies to a cache;
• beginning the second backup cycle while the backup device is unavailable and responsive to determining that the backup device is unavailable diverting second backup copies to the cache;
• and
• during or after the second backup cycle, when the backup device is determined to be available, copying the first and second backup copies from the cache to the backup device.