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To change the disk discovery path in any of the Oracle GUI tools (such as runInstaller, config.sh, and asmca),
select Change Discovery Path.
Then change the default value to the appropriate values for the environment.
6.4.2 UDEV and DM-Multipath
This section provides UDEV examples for DM-Multipath pseudo devices intended for ASM. The snippet from
/etc/multipath.conf in Figure 46 is used for the examples in this section.
For additional usage and configuration information on DM-Multipath I/O with ASM and UDEV, see information
provided at My Oracle Support, as well as Red Hat Enterprise Linux 6 DM multipath documentation and Red
Hat Enterprise Linux 7 DM multipath documentation.
6.4.2.1 UDEV with unpartitioned DM-Multipath pseudo devices
Assuming a prefix and suffix were used when naming the DM-Multipath device alias (Figure 46), a single
UDEV rule can be used to manage device persistence of these devices. All candidate devices can be
identified in the UDEV rule by testing the equivalency of:
• Device environment key DM_NAME against the unique prefix of the DM-Multipath alias names
• KERNEL against all kernel device-mapper devices (dm-*)
# cat /etc/udev/rules.d/99-oracle-asm-devices.rules
ACTION=="add|change", KERNEL=="dm-
*",ENV{DM_NAME}=="oraasm*",OWNER="grid",GROUP="oinstall",MODE="0660"
Note: Each rule begins with ACTION and occupies one line in the rule file. Because the margins of this
document do not support the length of the rule, the previous rule wraps to a second line.