[CentOS] Odd issue with custom udev rule at boot

James Pearson james-p at moving-picture.com
Thu Jun 16 10:00:43 UTC 2011


James A. Peltier wrote:

> BTW: Can anyone try this to see if it is in fact a bug or not?
> 
> Create a file called
> 
> /etc/udev/rules.d/99-udev-override.rules
> 
> that contains
> 
> KERNEL=="tty[A-Z]*", GROUP="some_other_group_than_uucp", MODE="0660", OPTIONS="last_rule"
> 
> with mode of 0644 reboot and confirm that the group permissions
> change or not.  If you change the mode however you will see that the
> mode *does* change.

Works for me.

Before:

# ls -l /dev/ttyS*
crw-rw---- 1 root uucp 4, 64 Jun 15 16:16 /dev/ttyS0
crw-rw---- 1 root uucp 4, 65 Jun 15 16:16 /dev/ttyS1
crw-rw---- 1 root uucp 4, 66 Jun 15 16:16 /dev/ttyS2
crw-rw---- 1 root uucp 4, 67 Jun 15 16:16 /dev/ttyS3

Created /etc/udev/rules.d/99-udev-override.rules containing:

KERNEL=="tty[A-Z]*", GROUP="users", MODE="0660", OPTIONS="last_rule"

After reboot:

# ls -l /dev/ttyS*
crw-rw---- 1 root users 4, 64 Jun 16 10:45 /dev/ttyS0
crw-rw---- 1 root users 4, 65 Jun 16 10:45 /dev/ttyS1
crw-rw---- 1 root users 4, 66 Jun 16 10:45 /dev/ttyS2
crw-rw---- 1 root users 4, 67 Jun 16 10:45 /dev/ttyS3

However, if I use a group name that isn't in /etc/groups (but is defined 
in say NIS), then the group is set to root after a reboot - but using 
the GID of that group works.

James Pearson



More information about the CentOS mailing list