UDEV Question

davnetuk · 10-08-2014, 10:11 AM

Hi there,

I am trying to create a udev rule that will automatically rename a device to an Oracle ASM path on system boot.

For example:
/dev/sdd should become /dev/oracleasm/disk001
/dev/sde should become /dev/oracleasm/disk002

I am aware of how to do this with UUID's, however, the issue with UUID's is that you always have to know the value. Each time a new disk is added, you have to go and get the UUID.

In my situation, I know that any disk from /dev/sdd will be an Oracle ASM disk.

Here is my current rule, however it doesn't work on more than 1 disk:
KERNEL=="sd[d-z]", BUS=="scsi", ENV{DEVTYPE}=="disk", NAME="oracleasm/disk00%n", OWNER="oracle", GROUP="oinstall", MODE="0660"

The idea being that each time another disk is found, the disk number will increment by one.

Can anyone help with the above?

Thanks.

onebuck · 10-08-2014, 02:48 PM

Hi,

Maybe these links can be of help;

Quote:

From Slackware®-Links;
-- UDEV:
Udev: Introduction to Device Management In Modern Linux System <- 'Udev supplies a dynamic device directory containing only the nodes for devices which are connected to the system. It creates or removes the device node files in the /dev directory as they are plugged in or taken out.'
Writing udev rules <- 'This document assumes that you have udev installed and running OK with default configurations. This is usually handled by your Linux distribution.'
Persistent block device naming <- 'This article describes how to use persistent names for your block devices. This has been made possible by the introduction of udev and has some advantages over bus-based naming.'

Hope this helps.
Have fun & enjoy!

davnetuk · 10-10-2014, 04:14 AM

Thanks for the links. In the end I couldn't get the numeric thing to work, i.e. call the disks disk001, disk002 and so on.

I compromised and ended up going with this: disk00sdd, disk00sde etc

The rule to do this was:
file = /etc/udev/rules.d/99-oracle-asmdevices.rules
KERNEL=="sd[d-z]", BUS=="scsi", ENV{DEVTYPE}=="disk", NAME="oracleasm/disk00%k", OWNER="oracle", GROUP="oinstall", MODE="0660"

Thus any disk from sdd onwards will have that rule applied. For me this is fine as only sda,b&c need to be non-ASM disks.