[systemd-devel] udev and dm inotify problems

[Lennart Poettering]

On Sun, 26.07.15 11:39, Oleksii Shevchuk (alxchk at gmail.com) wrote:

> Andrei Borzenkov <arvidjaar at gmail.com> writes:
> 
> >
> > Could you verify with e.g. inotifywatch whether inotify event was
> > generated by kernel?
> >
> 
> It turns out, that for some reason I have several dm devices:
> 
> # ls -l /dev/mapper/
> crw-rw---- 1 root dialout  10, 236 ??? 25 09:52 control
> brw------- 1 root root    254,  12 ??? 25 09:52 _dev_dm_5
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 Media-Doc -> ../dm-3
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 Media-Music -> ../dm-1
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 Media-Tmp -> ../dm-2
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 OS-home -> ../dm-5
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 OS-kernel -> ../dm-7
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 OS-portage -> ../dm-4
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 OS-prefix -> ../dm-8
> brw------- 1 root root    254,   0 ??? 25 09:52 OS-root
> lrwxrwxrwx 1 root root           8 ??? 25 09:52 OS-Software -> ../dm-10
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 OS-var -> ../dm-9
> lrwxrwxrwx 1 root root           7 ??? 25 09:52 OS-VM -> ../dm-6
> brw------- 1 root root    254,  11 ??? 26 11:36 swap <<---- SWAP is here
> 
> Also I have separate device - /dev/dm-11, with same major/minor.

Most likely you built your LVM/dm userspace without proper udev
support, or left support in there that creates device nodes on its
own.

Nowadays with devtmpfs device nodes are created exclusively by the
kernel and userspace should never create a single device node. If your
LVM/DM tools still do, then they have been built with incorrect
build-time settings.

Note that LVM/DM issues are probably better discussed at the LVM/DM
mls than here...

Lennart

-- 
Lennart Poettering, Red Hat