How can I set persistent raw device permissions in Red Hat Enterprise Linux 4 or 5?
Environment
- Red Hat Enterprise Linux 4 and 5
Issue
- How can I set persistent raw device permissions in Red Hat Enterprise Linux 4 or 5?
Resolution
From Red Hat Enterprise Linux 4 on, udev is introduced which could help solve the problem. In Red Hat Enterprise Linux 4, /etc/udev/permissions.d is the directory where permission configuration file 50-udev.permissions is located. Red Hat Enterprise 5 uses a later version of udev and manages permission in the file /etc/udev/rules.d /60-raw.rules.
In Red Hat Enterprise Linux 4, here is the partial content of /etc/udev/permissions.d/50-udev.permissions:
# cat 50-udev.permissions
# raw devices
ram*:root:disk:0660
raw/raw2:test:test:0660
raw/*:root:disk:0660
It means that raw2 device's user is test and group also test while other raw devices' permissions is set by default.
Note: Don't put the raw2 line behind raw/* line because raw/* line will set all raw devices as default including raw2 device.
Then restart rawdevices:
# service rawdevices restart
# ls -l /dev/raw/
total 0
crw-rw---- 1 root disk 162, 1 Nov 21 16:05 raw1
crw-rw---- 1 test test 162, 2 Nov 21 16:05 raw2
crw-rw---- 1 root disk 162, 3 Nov 21 16:05 raw3
In Red Hat Enterprise Linux 5, permission is set in /etc/udev/rules.d /60-raw.rules file:
# cat /etc/udev/rules.d/60-raw.rules
ACTION=="add", KERNEL=="raw*", OWNER=="root", GROUP=="disk", MODE=="0660"
ACTION=="add", KERNEL=="raw2", OWNER=="test", GROUP=="test", MODE=="0660"
After configuring, please restart udev:
# start_udev
# ls -l /dev/raw/
total 0
crw-rw---- 1 root disk 162, 1 Nov 21 16:05 raw1
crw-rw---- 1 test test 162, 2 Nov 21 16:05 raw2
crw-rw---- 1 root disk 162, 3 Nov 21 16:05 raw3
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