While running a mysqldump of my databases I received an error. Running a check on that specific database told me that the comments.MYD file was not found.

Investigating on the system showed me that due to an error the filesystem containing /var/lib/mysql was mounted read-only. Running a fsck on that specific filesystem solved that error but didn’t fix my corrupted table.

phpMyAdmin showed that the table was in use and while performing a check or repair it complained about the missing file.

The comments.MYD file was indeed missing, but there was a comments.TMD file, which wasn’t there for all the other tables.

Moving this TMD file to MYD solved the issue. I could repair the table and the check is again successful.

During this problem wordpress didn’t complain but it just didn’t show my comments. But I have no clue what caused this problem.