As part of the Cloud Manager's process for changing a deployment's storage engine via automation, backup files are created. They are not removed at the end of the process, but rather left behind as a precaution.

Assuming a dbpath for the mongod of /data/mongo the backup file will be /data/mongo.bak.UNIQUENAME where UNIQUENAME is a randomly generated string.

Given the unique name, conflicts with future change attempts are not a problems. However, these backups will use up disk space.

Users should be informed of the backups' existence and advised to remove them at the appropriate time.