[PC-BSD Testing] Automounting of USB drives - Why is it a problem?

Kris Moore kris at pcbsd.com
Thu Apr 16 06:24:31 PDT 2009

Arthur wrote:
>>> Hello List,
>>> For some time now, I have been baffled by one thing: Mac OS X somehow 
>>> has FreeBSD under the hood. When you connect a USB stick (flash disk, 
>>> external drive) to a Mac, it gets automounted, yet the same does not 
>>> happen on FreeBSD.
>>> I have seen several questions being asked on this list about this 
>>> feature, but the answer is neither here nor there.
>>> There is even a port (sysutils/automounter) that I believe is 
>>> supposed to help towards this, but again it's not as easy as it seems 
>>> to be.
>>> Now my question is just one: Why should it be this difficult for 
>>> FreeBSD to have the automount feature within the base system?
>>> If OS X is doing it, Linux is doing it, FreeBSD can do it.
>> Mount usb dev, work with it somehow ( copy there or from), and then 
>> NOT umounted it, remove it.
>> You'll probably get kernel panic and system crash. This happen in 
>> almost all cases.
>> While BSD -Stable didn't merge new USB stack, which would behave 
>> normal in such situation, auto-mount not good idea.
>> That's my IMHO :)
>> Sure, but you haven't seen a Mac OS X panic so far, right? Perhaps you 
>> haven't seen/used any Mac, so you are not to blame:-)
>> All I am wondering about is why it cannot happen in FreeBSD world?
> I have not had any issues with USB drives auto-mounting on my PC-BSD 
> installs ever.
> Arthur

I have seen my Wife's system crash once in a blue moon, after removing 
an unmounted USB stick. I think the long-term solution is going to be 
when we switch over to the new USB2 stack in 8.0. Its being actively 
developed now, and I know it fixes a lot of issues with my USB keyboard 
/ mice working on some of the latest GigaByte motherboards.


Kris Moore
PC-BSD Software

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