click-click in floppy disk drive

Polytropon freebsd at
Wed Oct 23 11:46:38 UTC 2013

On Tue, 22 Oct 2013 19:56:37 -0600 (MDT), Warren Block wrote:
> Some background things like HAL may poll removable media devices to 
> detect new media, and this might cause a floppy to click.  Could depend 
> on the manufacturer of the drive.  That would be my first guess, anyway.

That's what I tought in the first place. It's very unlikely
that the system's default periodic scripts could trigger a
continuous activity of the drive (even though I can imagine
that a pending umount or something comparable could have
caused this). Systems like HAL that commonly belong to GUI
desktop environments can, if they are set to polling the
drive's state, cause such activity, but it depends on _how_
they do it and _how_ the drive acts.

For example, I've tried with my external USB drive. As long
as there is no floppy in it, it cannot be encouraged to show
any activity with a typical null command. But if a floppy is
in the drive (unmounted of course), the drive will light up
and buzz. This only works as long as there's a floppy in the
drive, so I assume the drive already contains some "logic"
of reporting a _possible_ disk to the firmware. Of course,
other manufacturers might handle this very differently, and
maybe even rely on a proprietary driver to show the _desired_
way of operation (instead of annoying clicking for evey poll).

At least, the classic Amiga floppy drive wasn't that annoying
when determining if there's a floppy disk in the drive - much
more advanced than what the PC usually did ("Press ENTER for
next disk!"). ;-)

> If that is the cause, it may be possible to tell whatever is doing the 
> polling to skip the floppy device.

The OP should have a look a HAL configuration and maybe remove
the floppy drive's device from the list for polling.

There might be other mechanisms than HAL, maybe also tied to a
desktop environment, that could cause that kind of polling. It
could even be a user program - but as far as I know, no such
thing is part of the FreeBSD OS...

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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