Maintenance

Over time your Mastodon instance will fill up with messages and media requiring you to upgrade to a larger storage.

To prevent this from happening too quickly, you may choose to delete older content.

Local vs Remote

Mastodon distinguishes two types of content:

Content generated locally, by your own users. This content is unique and should probably be stored for a longer period.
Content generated remotely, by users on other instances. This content is essentially redundant can be deleted sooner.

The settings to clean up remote content are found by going to Preferences > Administration > Server Settings > Content Retention.

Our recommendations:

Media cache retention period: 7. Keeping this number low saves a lot of storage and because missing media is re-downloaded on demand, you can safely do so.
Content cache retention period: 730. 730 days equals 2 years. This means all conversation are retained for 2 years. After 2 years, remote messages will disappear from the conversation.
User archive retention period: 7. This affects temporarily generated archives only. It does not affect the actual content of your server.

Mastodon does not provide instance-wide clean-up for local content.

You can encourage your users to enable auto-delete for older posts. They can do this under Preferences > Automated post deletion.