[lvm-devel] [dm-devel] linux-2.6.35+ causes LVM to fail with " device-mapper: version ioctl failed: Inappropriate ioctl for device"

[Jeff Chua]

On Mon, Aug 16, 2010 at 11:55 PM, Alasdair G Kergon <agk at redhat.com> wrote:
> On Mon, Aug 16, 2010 at 11:32:15PM +0800, Jeff Chua wrote:
>> It'll be nice if lvm returns a more meanful message like "ioctl
>> failed. Check /proc/misc to ensure the device is mapped correctly."
>
> No need - LVM should be quite capable of detecting/dealing with the problem.

Ok, cool.

>> To take care of it automatically with udev, I'm doing this in rc.S
>> if [ -f /sys/devices/virtual/misc/device-mapper/dev ]
>> then
>>         NODE=$(</sys/devices/virtual/misc/device-mapper/dev)
>>         rm -f /dev/mapper/control
>>         mknod /dev/mapper/control c ${NODE/:/ }
>
> The whole point of this change was to trigger the loading of dm-mod
> automatically for people using it as a module, based on using a known
> major/minor number instead of a dynamic one only known after the module
> has been loaded.  That needs to happen regardless of whether someone is
> using udev or not.
>
> This can all be fixed easily enough in userspace.

I'm not using module. It's all built-in to the kernel. Hopefully this
would be taken care of as well. That's why I had it in rc.S just
before the lvm filesystems are mounted.

Thanks,
Jeff.