SCSI device not created upon a CF card plug in

[Ivan Voras]

Milan Obuch wrote:
> On Wednesday 22 July 2009 09:38:50 Ivan Voras wrote:
> 
> [ snip ]
> 
>>>> After the CF card is plugged in:
>>>> $ ls -l /dev/ | grep da
>>>> crw-r-----  1 root    operator    0, 105 Jul 22 13:18 da0
>>>> crw-r-----  1 root    operator    0, 106 Jul 22 13:18 da1
>>>> crw-r-----  1 root    operator    0, 107 Jul 22 13:18 da2
>>>> crw-r-----  1 root    operator    0, 108 Jul 22 13:18 da3
>>>>
>>>> After reboot while the CF card is plugged in:
>>>> $ ls -l /dev/ | grep da
>>>> crw-r-----  1 root    operator    0, 105 Jul 22 13:24 da0
>>>> crw-r-----  1 root    operator    0, 106 Jul 22 13:24 da1
>>>> crw-r-----  1 root    operator    0, 110 Jul 22 13:24 da1s1
>>>> crw-r-----  1 root    operator    0, 107 Jul 22 13:24 da2
>>>> crw-r-----  1 root    operator    0, 108 Jul 22 13:24 da3
>>>>
>>>> My questions in this regards are:
>>>> 1. Is this an error/bug in FreeBSD 7.2?
>>> This is known limitation of, I think, GEOM stack.
>> No, it is certainly not. What would be the point?
>>
> 
> Please re-iterate :)
> 
> When GEOM is signalled about new device, it tries to understand data 
> structures - MBR, partition table, etc. The key is 'when signalled'. So this 
> is not limitation of GEOM per se, just missing signalling of new device/data 
> media arrival.

Ah yes, if the reader always signals the device present but doesn't 
signal media insertion, it would lead to the described problem.

I agree there isn't a good solution apart from polling.