Recently I stumbled over a posting on the German MySQL Forum from a user that accidentally removed all table files from a MySQL Server's data directory with a misbehaving shell script. He was surprised to find out that the server happily continued to serve requests and his web site was still fully operational, even though /var/lib/mysql/<database> was completely emtpy! The reason for this in a nutshell: the rm command only removed the reference to the table files from the database directory, the files itself were not removed from the file system yet as the mysqld process still had the files opened. So as long as a process keeps a file open, the kernel will not release the disk space occupied by the file and it will remain intact, albeit no longer visible.

Of course, the user was now desperate to recover the deleted tables files and was …

Recently I stumbled over a posting on the German MySQL Forum from a user that accidentally removed all table files from a MySQL Server's data directory with a misbehaving shell script. He was surprised to find out that the server happily continued to serve requests and his web site was still fully operational, even though /var/lib/mysql/<database> was completely emtpy! The reason for this in a nutshell: the rm command only removed the reference to the table files from the database directory, the files itself were not removed from the file system yet as the mysqld process still had the files opened. So as long as a process keeps a file open, the kernel will not release the disk space occupied by the file and it will remain intact, albeit no longer visible.

Of course, the user was now desperate to recover the deleted tables files and was …