The disqualification can happen because of too many failed audits. Disqualification for downtime can happen only for more than 30 days offline.
Audit can be failed if your node is online, responds on audit requests but:
- did not provide a piece for audit within 5 minutes, did the same two more times for the same piece;
- have provided a corrupted piece;
- is unable to provide a piece, because it’s lost (or the node is lost an access to it).
Too many failed audits in row and node will be disqualified.