[systemd-devel] udev device mapper rules for early boot?

[Andrey Borzenkov]

В Mon, 10 Dec 2012 11:03:54 -0800
Nikolaus Rath <Nikolaus at rath.org> пишет:

> Hello,
> 
> I have created a udev rule to set the owner of a specific block device:
> 
> SUBSYSTEM=="block",
> ENV{DM_UUID}=="LVM-yYuoI8k05GWxZnz9BeEIwPUGGeojzF3dZZmXTYRqC051Tllj76OHdDlzYhKZUu7u",
> OWNER="1000"
> 
> If I disable and re-enable this logical volume with lvchange, it gets
> created with the correct owner.
> 
> However, when I boot the computer, the device is always owned by
> root:disk instead.
> 
> I checked my initrd, and the rule is present in lib/udev/rules.d as
> 99-udev-custom.rules.
> 
> Does anyone have a suggestion of how I could debug this further? Why is
> my rule ignored when the volume comes up the first time?
> 

The simplest reason would be that DM_UUID is not defined at all. It is
set by another udev rule and may be this rule is missing, or
prerequisites for this rule are missing ... if your initramfs supports
launching shell, you could udev database.

Or this device does not appear in initramfs and is setup later.