I have a DB in full recovery mode. The DB makes a full backup every Friday night, then a differential backup all other nights. We perform a log file backup every two hours. I noticed in the maintenance plan that the log file backup is set to expire after seven days. Does it make sense to keep the log file backups that far back if we have Db backups, or is it just wasting space on the drive (which is at a permium at the moment.)
It is generally considered best practice to keep DB backups and log files for as long as you need them. If your business has a need to recover a database to a point in time from backups taken up to a week ago, then you should keep those backups and logs. However, if the business would only need to recover to a point in time within the last 24 hours you can safely retain only the logs and backups for 2 days.
Additionally, there is no reason to maintain the backup files (DB & log) on local SQL Server drives. If space is truly at a premium, consider copying the backups off of the local drive retaining only enough to keep whatever is taking up the available drive space from consuming the space needed for your backups. Otherwise you'll find that the backups are unable to complete due to lack of space