On Sat, 22 Nov 1997, Paul Goyette wrote:

.. On Sat, 22 Nov 1997, Adrian Rollett wrote:
.. 
.. > Please take this as a question from an inexperienced sysad and not an
.. > accusation, but i was curious what reboot -n does, looked it up, and the
.. > man page sez:
.. > 
.. >      -n      If the -n option is specified, the file system cache is not
.. >              flushed.  This option should probably not be used.
.. > 
.. > What is the raison d'etre for reboot -n ?
.. 
.. Well, there are times when you don't want to flush the cache, like just
.. after you've run fsck on a mount disk!  Otherwise, a cache flush might
.. well overwrite the good info that fsck puts on the disk with bad info that
.. had been in the cache.
.. 
.. Personally, I prefer not to run fsck on a mounted disk.  If I have to run
.. fsck against my root partition, I first ``mount -u -o rdonly /'' to make
.. the disk read-only and flush the cache.  Then I can run fsck knowing that
.. a subsequent cache flush won't overwrite anything.  When I'm done, I can
.. remount the root partition with ``mount -u /''

Maybe the time has come to declare the -n option as a mainly historically
relevant option (but still leave it in the system). In the "good old
days", before a single user boot started with / mounted read-only, it was
necessary to be able to reboot with -n after running fsck, but nowadays
I can hardly see any reason for the -n option to be useful.

Anyway, it is an option of the kind that you'll never want (i.e. need) to
use unless you really understand a lot about the file system to see why
it is needed in a given case.

- Erik