Q: in v.1.9.4. How does the attachments works in terms of being saved in the server?A: Like the previous version they are stored in the database.  Unless you change that.Q: Do the need to be manually migrated from version to versions in order to work?A: Not if you upgrade your existing setup.Q: Do the get save in a folder on the server? if not, where?A: No, see answer to your first question.Q: What happens to these attachments when osticket gets updated?A: Nothing.Q: Is it possible to prevent users and staff to upload attachments entirely?A: Yes.  Admin panel -> Settings -> Tickets -> Ticket Attachment Settings.Q: Additionally, what are your thoughts in terms of space that this can take in the database?A: I don't have any, but generally the larger the database the more powerful server (or cluster) is needed to power it adequately.Q: would this lead to some form of database corruption after years of saving attachments?A: no more so than years of using a database, upgrading a database, moving a database, etc.

Sounds like a bug.  Looks like its been reported.:)