Yesterday, one of my WordPress sites started acting REALLY strange. All of my categories and tags disappeared after I made a post, and I started freaking out.
Of course, I had a backup of the database, but it was 6 days old.. Not a huge deal, but more of an inconvenience.
Thankfully, before I did anything drastic, I FTP’d into my account and saw that the php_errors file in my /logs directory was growing. When I peeked inside, I saw a ton of errors that read:
WordPress Database Error: Got Error 28 From Storage Engine
Searching for this error string led me to this post, which told me that this was a MySQL error and has nothing to do with WordPress directly. Apparently I was either out of space on /tmp (wherever tmpdir is), or I had too many files in /tmp (even if there is lots of free space).
So I contacted my hosting company, and 10 minutes later they had taken care of the problem.
Now you know.. If you ever come across a similar issue, check your php_errors file first, and if that’s the message you’re seeing, let your host know and they’ll take care of it for you.