Configuring Storage Device Path Persistence Manually

You can maintain storage file path persistence by creating a rules file.

By default, the device file naming scheme udev dynamically creates device file names when the server is started, and assigns ownership of them to root. If udev applies default settings, then it changes Oracle device file names and owners for the disks, making the disks inaccessible when the server is restarted. For example, a voting disk on a device named /dev/sdd owned by the user grid may be on a device named /dev/sdf owned by root after restarting the server.

If you use Oracle ASMFD, then you do not have to ensure permissions and device path persistence in udev.

If you do not use Oracle ASMFD, then you must create a custom rules file. Linux vendors customize their udev configurations and use different orders for reading rules files. For example, on some Linux distributions when udev is started, it sequentially carries out rules (configuration directives) defined in rules files. These files are in the path /etc/udev/rules.d/. Rules files are read in lexical order. For example, rules in the file 10-wacom.rules are parsed and carried out before rules in the rules file 90-ib.rules.

When specifying the device information in the udev rules file, ensure that the OWNER, GROUP, and MODE are specified before all other characteristics in the order shown. For example, to include the characteristic ACTION on the UDEV line, specify ACTION after OWNER, GROUP, and MODE.

Where rules files describe the same devices, on the supported Linux kernel versions, the last file read is the one that is applied.

• Configuring Device Persistence Manually for Oracle ASM
  Complete these tasks to create device path persistence manually for Oracle ASM.