[linux-lvm] pvscan: /dev/sdc: open failed: No medium found

[Zdenek Kabelac]

Dne 23. 04. 19 v 16:27 David Teigland napsal(a):
> On Mon, Apr 22, 2019 at 11:15:53PM -0600, Gang He wrote:
>> Hello List,
>>
>> One user complained this error message.
>> The user has a usb sd card reader with no media present.  When they issue a pvscan under lvm2-2.02.180 the device is opened which results in 'No medium found' being reported.
>> But lvm2-2.02.120 did not do this (the device appears to get filtered out earlier). The customer views the 'No medium found' message as an issue/bug.
>> Any suggest/comments for this error message?
>>
>> The detailed information is as below,
>> lvm2 2.02.180-9.4.2
>> OS: SLES12 SP4
>> Kernel 4.12.14-95.3-default
>> Hardware: HP ProLiant DL380 Gen10
>>
>> After upgrade from sles12SP3 to SP4, customer is reporting the following error message:
>>
>>   # pvscan
>>   /dev/sdc: open failed: No medium found
>>   PV /dev/sdb   VG Q11vg10         lvm2 [5.24 TiB / 2.00 TiB free]
>>   Total: 1 [5.24 TiB] / in use: 1 [5.24 TiB] / in no VG: 0 [0   ]
> 
> I've heard this a few times now, I guess we should drop it, it's probably
> more trouble than help.
> 

This hotfix patch:

https://www.redhat.com/archives/lvm-devel/2019-April/msg00067.html

is unfortunately faulty and should be reverted.

The core problem is - the filtering layer is somehow bypassed where cdrom used 
be recognized as unsuitable device for opening.

So the error reported by lvm2 is really an error where lvm2 should not be 
trying to even open such device.

The switch of message severity not only 'waves' this particular  cdrom open 
error - but also all other device open errors.


Zdenek