HowtoMatrix

Release Found: Red Hat Enterprise Linux 3 and Red Hat Enterprise Linux 4

There is a condition in both Red Hat Enterprise Linux 3 and Red Hat
Enterprise Linux 4 where the kernel fails to properly clean up inodes
after an NFS filesystem is unmounted. When this happens, the following
message is printed to the /var/log/messages file:

kernel: VFS: Busy inodes after unmount. Self-destruct in 5 seconds.  Have a nice day...

It is highly likely that after this message is printed the system
will eventually try to access one of these busy inodes, resulting in a
kernel panic. The panic itself could happen right away, or it could
happen at some point in the future - perhaps as much as several days
later.

Read more at Red Hat Magazine