why didn't sync work for me?

[Geoff Kuenning]

I have a single-user desktop machine.  One of my .cshrc aliases is the
following:

	alias	s	sync \; sync

I also run a pseudo-job-control program that gives me four tty ports on my
console.  My standard shutdown procedure is to shift to each suffix in
turn, checking to be sure I don't have an editor running or something, and
typing 's' in each one.  I finish in the suffix I use for superuser work, and
in that I type 's' at least once, and frequently four or five times.  Then I
run a little program that reads a file in /etc, executes a sync(2) primitive,
and runs an ioctl on each disk to move the arm to the shipping position.

All well and good, right?  Well, this morning when I booted, fsck found
an unconnected inode on the root filesystem.  I reconnected it, and checked
it out -- it contained a sort temp file that was at least an hour old at
the time of the boot.  Now /etc/init does a sync every five minutes, not to
mention all the sync's I did before shutdown.  Yet the disk was left in an
inconsistent state.  Why?
-- 

	Geoff Kuenning
	...!ihnp4!trwrb!desint!geoff