One way to limit the disk space used by messages on an NNTP server is to implement a retention policy. This policy sets a time limit for how long messages are stored on the server before they are automatically deleted. For example, you could set a policy to delete messages after 30 days, or you could set different time limits for different newsgroups.
Another option is to implement quotas for users or newsgroups. This sets a limit on the amount of disk space that can be used for messages. Once the quota is reached, the server will stop accepting new messages until space is freed up.
Some NNTP server software providers may also offer compression options, which can help reduce the disk space used by messages. Additionally, regularly performing maintenance tasks such as archiving old messages or optimizing the database can help keep the disk space usage under control.
