removing external usb hdd without unmounting causes reboot?
kris at pcbsd.com
Wed Jul 18 20:34:22 UTC 2007
Jeremy Chadwick wrote:
> On Wed, Jul 18, 2007 at 11:54:19AM -0700, Kris Moore wrote:
>> That being said, I think it would be a good idea to at least have the
>> kernel / HAL or some process maybe warn the user that they should
>> unmount the USB disk first, to prevent data loss at minimum. But I think
>> this can be improved, so you don't have to deal with an entire system
>> panic :P When that happens you gotta reboot, fsck, and run the risk of
>> something really being corrupted on the drive :(
> So there's two issues here:
> 1) Kernel panics when a device (regardless of type (USB, SATA, etc.))
> is removed from the system with filesystems mounted,
> 2) Concern over data loss when device is removed.
> As I mentioned earlier in the thread, Windows addresses #2 by marking
> all filesystems on USB storage devices (thumb drives, HDDs, etc.) as
> synchronous (e.g. mount -o sync). The impact is slow I/O, but it's
> It seems like we'd be able to implement such a transparent "feature"
> into the subsystem where filesystems mounted from USB devices would use
> synchronous I/O (mount -o sync). I don't know how this would be coded,
> since there would have to be some way to figure out a physical device
> type (USB mass storage devices show up as /dev/daXXX).
> Providing an override option for those who know what they're doing,
> (umount /mnt then physically remove device) would be nice too.
> This would alleviate concerns over data loss, would it not?
This sounds like an excellent idea to me. If something along these lines
were implemented, it would be very helpful for us on the desktop end of
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