Re: New Zaurus Wishlist - removable media handling

From: David Golden (
Date: Wed Jun 26 2002 - 19:19:49 EST

> And Unix filesystems were NOT designed for removable media.

(LKML cc'd because this rant *might* be coherent enough to explain it
to Linux kernel hackers)

The main problem I have with the Linux filesystems is this:

Forcing the user to think about which drive he stuck a disk or other
removable medium into each time he wants to access it is silly - people
often think of the disk as an entity independent of whichever drive it
happens to be in at the time.

It drives me crazy^Hier when software insists on its cdrom being /mnt/cdrom,
for example - there should be some way for the software to ask for
"Give me a disk called xyzzy1, and I don't care what drive it is!", and
preferably by just trying to open e.g. /mnt/xyzzy1/

Once you've worked with a system that simply doesn't give a damn
what drive you put a removable disk into, or even lets you pretend an
arbitrary directory in the filesystem is that disk, it's very difficult to be
comfortable on ones that do give a damn.

Accessing the removable medium by the volume name of the medium, _not_
  (or not solely) by the drive it is in is something that the AmigaOS (the
"classic" AmigaOS, not the Intent platform plastered with Amiga-trademarks)
got "right", and Linux and Windows tend to get "wrong". (note the inverted
commas - "right" and "wrong" are merely my opinion as a one-time Amiga
user and now as a desktop linux user)

Amigas handled this with Assigns / amiga-style logical volumes (distinct from
unix/linux LVMs, which are block-level) - if you stuck a CD named xyzzy1 in
drive CD0:, you could access it via "CD0:" - "the volume currently in drive
CD0:, whatever it may be called" , or via "xyzzy1:" - " the volume called
xyzzy1, whatever drive it may be in"

Yes, this could be (fairly) trivially accomplished by a daemon managing a few
symlinks, or (better) the kernel automounter combined with the Linux vfs's
support for multiple mounts of the same filesystem in different places.

Unfortunately, there's no standard for it, and no desktop distros implement
one, preferrring to have half-assed ad-hoc code in installers. (AFAIK on
windows too, installers and individual applications for the most part write
ad-hoc code to retreive the volume name, after scanning for drives. That's
not general or scaleable...)
obZaurus: The Zaurus, of course, inherits just the same problem, as far as I
can tell - /mnt/cf is whatever compact flash card happens to be in at the
time, there's no direct way to ask the linux filesystem for a particular
removeable medium.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Sun Jun 30 2002 - 22:00:11 EST