Re: mount -o remount

Richard B. Johnson (
Wed, 11 Jun 1997 17:19:31 -0400 (EDT)

On Wed, 11 Jun 1997, Pawel S. Veselov wrote:

> Hello, People !
> Today, I have some problems with BSD, when found out, that they
> disabled "remount" option in mount. But they made "force" option, that can
> directly change attributes for file systems to make it readwrite, readonly,
> etc. I think it's really better than remount, as if there is no need for
> unmounting fs. Can it be implemented for Linux ?
> Bye.
> --

But we don't unmount the fs anyway except for shutdown. The kernel "mounts"
the root file-system once it finds it so it can start init. The root
file-system is read-only so that it can be checked/repaired using fsck
during startup.

Then, when init executes some shell-script, fsck is executed for each
"standard" file system found in /etc/fstab. File-systems like ISO9660
and MS-DOS are not fsck'ed. After any file-system repair, the file
systems are mounted read/write as:

# mount -n -o remount /
| | |______ root
| |________________ option to remount R/W
|___________________ ignore /etc/mtab until mounted.

# mount -t type /dev/disk_partition /where
... for every device found in /etc/fstab.

These devices are not "unmounted" then "remounted".

Changes in syntax in BSD is unfortunate. There are a lot of changes
in semaitics being made for no good reason. This means that learning
"Unix" on a DEC or BSD machine will not qualify you for running any other
machine, learning "Unix" should suffice but for protectionist reasons,
commands that do exactly the same thing on another machine are often
completely different. SGI makes a good machine but you can't change the
netmask! __THEY__ decided that was not a good netmask!
The DEC Alpha has the same problem. It will silently ignore any netmask
it doesn't like.

Why? Because. That's all.

Don't unbreak something that is not broken.

Richard B. Johnson
Analogic Corporation
Email :,
Penguin : Linux version 2.1.42 on an i586 machine (66.15 BogoMips).
Warning : It's hard to stay on the trailing edge of technology.