An image forming system includes a login management unit, a job execution unit, a log management unit, and a mode accepting unit. The login management unit is configured to manage login of a user. The job execution unit is configured to execute a job after the user has logged in. The log management unit is configured to manage a job log of the job. The mode accepting unit is configured to accept a specification of a mode to store the job log. Acceptable modes where the mode accepting unit accepts a specification include a mode where the login management unit does not permit login if the log management unit determines that there is no free space to store the job log.