RFS - losing disk free space count

[Barry Shein]

From: "Shawn F. Mckay" <shawn at mit-eddie.MIT.EDU>
>When the whole thing started I had about
>600 blocks free on /dev/ra0a. (My root partition). But I soon got messages
>saying I was out of space. In fact, doing a df show'd me being at 102%, 0
>free.

4.x (x>1) reserves 10% (actually, it's settable, but that's the default) of
the disk. Thus you can have a disk up to 110% full. The reason is that the
disk block allocation routines start to slow down excessively with more than
90% of the disk full. The super-user is allowed to allocate this last 10%.

Is this what is causing your "problem"? It's not a bug, it's a...

The fact that you got errors at 102% could be caused by a number of things:

	a) If you were the super-user the other 8% might have been
	eaten up by a tmp file but released when the compile failed
	(ie. before you got a chance to do a 'df'.)

	b) If you weren't root something else was eating blocks
	while you were working, you were denied @100% but some other
	process ate the 2% (I dunno, a print spooler or mail daemon?)
	by the time you did a 'df'.

Solution: free up some disk space on root (c'mon do you really need that
oovmunix and /etc/termcap.orig file :-) or work on another disk.

	-Barry Shein, Boston University