The [tt]-k[/tt] option of [tt]df[/tt] is not reporting all available space on the filesystem. It's reporting space available to unprivileged users. When a filesystem is set up, you define a percentage of the space that is off limits to normal users (see the "[tt]-m free[/tt]" option of [tt]newfs[/tt]). This "off limits" space gets added to the [tt]used[/tt] column, even though it might not actually be used. So, the [tt]used[/tt] column is all of the space actually used, plus all of the "off-limits" space that only privileged users can use.
The off-limits space is so you can hit 0% free on a filesystem like [tt]/[/tt] (as reported by [tt]df[/tt]), but the OS doesn't crash (yet) because the OS still has a little space to use. It gives you a few moments to savor the adrenalin while you hunt for files to kill.
You can see the discrepency within [tt]df[/tt] too. Try both the [tt]-b[/tt] option and the [tt]-k[/tt] option (separately, not together). The [tt]avail[/tt] column for the [tt]-b[/tt] should be ALL available space. The [tt]avail[/tt] column for the [tt]-k[/tt] should be only space that normal users can use.
If you do a "[tt]du -dks /PREPROD[/tt]" and add that to the value given by "[tt]df -b /PREPROD[/tt]", it should come closer to the total filesystem size given by the "[tt]df -k[/tt]" command.
Is this clear or did I just confuse things?
Hope it helps.
