[linux-lvm] what creates the symlinks in /dev/<volgroup> ?

[Chris Friesen]

If I run it I get this:

controller-1:/dev# vgmknodes -v
     Using logical volume(s) on command line.
     Found same device /dev/sda6 with same pvid Fw6C1IZABbnspIT23RbOGf2DXuB4zMhS
     Found same device /dev/sda5 with same pvid 1s1dPDodojAS0kqToIRy4hiXFjCp2t2o
     Found same device /dev/sda6 with same pvid Fw6C1IZABbnspIT23RbOGf2DXuB4zMhS
     Found same device /dev/drbd4 with same pvid 6yk0HVTSbU9Amo6mwPKt3nZPnBIXBlhR
     Found same device /dev/sda5 with same pvid 1s1dPDodojAS0kqToIRy4hiXFjCp2t2o
   The link /dev/cinder-volumes/cinder-volumes-pool should have been created by 
udev but it was not found. Falling back to direct link creation.


So it thinks that udev should have already made it.  Also, the symlink it 
generates looks different than the symlinks already in /dev/cinder-volumes, in 
that it points to /dev/mapper/<name> rather than pointing to the "real" 
/dev/dm-X device like the others.


controller-1:/dev# ls -l /dev/cinder-volumes/
total 0
lrwxrwxrwx 1 root root  7 Jun 20 17:57 anchor-lv -> ../dm-9
lrwxrwxrwx 1 root root 49 Jun 20 21:48 cinder-volumes-pool -> 
/dev/mapper/cinder--volumes-cinder--volumes--pool
lrwxrwxrwx 1 root root  8 Jun 20 17:57 
volume-0bc1df18-45d0-4477-9c57-36876d3f82d4 -> ../dm-19
lrwxrwxrwx 1 root root  8 Jun 20 17:57 
volume-2fff261f-8860-4b86-8b2e-49bddcf47e9b -> ../dm-17
lrwxrwxrwx 1 root root  8 Jun 20 17:57 
volume-48744604-6b02-4f11-ba02-3f692d109953 -> ../dm-15
lrwxrwxrwx 1 root root  8 Jun 20 17:57 
volume-8dabc793-e46d-4849-a2fb-dd3d4bc2c988 -> ../dm-20
lrwxrwxrwx 1 root root  8 Jun 20 17:57 
volume-be3c9ddb-a6eb-43ca-ac37-5554756a4c13 -> ../dm-16
lrwxrwxrwx 1 root root  8 Jun 20 17:57 
volume-eef89318-fa8e-4ca2-a8a7-fe8e143d8792 -> ../dm-14
lrwxrwxrwx 1 root root  8 Jun 20 17:57 
volume-f11a7d88-1ad3-4e89-a594-e824019725bb -> ../dm-18


Given the above, I think that something other than vgmknodes must be involved.

Chris


On 06/20/2016 03:03 PM, Ilya Boka wrote:
> Command vgmknodes
>
> On Mon, Jun 20, 2016 at 10:52 PM, Chris Friesen
> <chris.friesen at windriver.com> wrote:
>> Hi,
>>
>> Can someone tell me what creates the /dev/<volgroup>/<volume symlinks?  Is
>> this LVM or udev (and if udev, do you know which rule)?
>>
>> I'm seeing some interesting behaviour where if I create a thin pool it
>> creates a symlink for the pool, but once I create a thin volume within the
>> pool then the pool symlink disappears.
>>
>> Thanks,
>> Chris
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm at redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>
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>