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

[Zdenek Kabelac]

Dne 21.6.2016 v 17:22 Chris Friesen napsal(a):
> I'm using the stock CentOS7 version, I think.
>
>   LVM version:     2.02.130(2)-RHEL7 (2015-12-01)
>   Library version: 1.02.107-RHEL7 (2015-12-01)
>   Driver version:  4.33.0
>
> So are you saying that nobody should run "vgscan --mknodes" on a system where
> udev is managing the symlinks?

Yes - on such system this command should be used only in case of 'emergency',
udev doesn't work properly and you need links.

The links however will not be known to udev and likely whole system is
going to be crashing soon or is misconfigured in major way.


> I'm not sure what you're talking about as far as duplicates, I'm not seeing
> any duplicate devices.  The problem I see is that "vgscan --mknodes" or
> "vgmknodes" will both create an additional symlink when compared to the udev
> rules, and the additional symlink is not deleted when I deactivate the volume
> group.
>
> For what it's worth, in my lvm.conf I have "use_lvmetad = 0" and
>
> global_filter = [ "a|/dev/sda|", "a|/dev/drbd4|",  "a|/dev/sda6|", "r|.*|" ]

And now we are getting to the point on your problem:

"a|/dev/sda|"   will also match "a|/dev/sda6|"
(and /dev/sda5...)

If you would like to get only 'exact' '/dev/sda' you would need to use

^/dev/sda$

otherwise '/dev/sda' may appear anywhere as substring of your device path.

Regards

Zdenek