Filesystem - hiding system folders?

[Colin Watson]

(FWIW, although you may not care:)

On Wed, Mar 29, 2006 at 04:11:49PM +0200, Alan McKinnon wrote:
> /rofs: Dunno

"Read-only filesystem"; this gives you the raw contents of the live CD
you just booted, without the changes that were made in memory in the
process of booting and running it. This is used by the live CD installer
so that it can copy a known, standard image to your hard disk, which
makes installations from live CDs much easier to support.

> /sbin: System programs that normally only root uses like fdisk, mkfs*, 
> netstat. Separate from /bin so it can go in root's $PATH but not a 
> user's

It's actually on the $PATH for regular users in Ubuntu too, because we
got fed up of the million bugs of the form "such-and-such is in /sbin
but I have a use for it as a regular user", although of course you can
still take it off your $PATH if you want.

> /sys: works the same way that /proc works, but shows different stuff

This is a fair summary for new users, but /sys is closer to a view of
your hardware, while /proc is closer to a view of what's happening
inside the operating system kernel.

> /target: dunno

The installer copies files here; this is where the partitions you want
to install on are mounted and the newly-installed system is built.

> /usr: User programs not considered part of the base OS. Gnome goes 
> here for example

I'd describe this as "programs that aren't needed just to get the system
up and running, but are used later".

> /var: Data that is usable by more than one user like databases and the 
> package manager's record of what's installed already

The FHS describes this as "variable data"; my description might be
"system files that change while the system is running".

> You might think that this can be simplified, but it can't. 
> Joining /bin, /lib, /sbin and /usr into one directory is not a good 
> idea as you lose control of how the OS works. 
> Maybe /proc /sys /dev /lost+found /boot /initrd and /tmp could be 
> gathered under one dir called /system and similarly 
> with /mnt /cdrom /media /srv. But all that does is convert a linear 
> row of things into a more complex tree structure with no extra 
> benefit.

/rofs and /target could no doubt be moved somewhere else, but since they
only exist on live CDs and during the installation there's very little
impetus to bother.

Cheers,

-- 
Colin Watson                                       [cjwatson at ubuntu.com]