Home > Storage > PowerStore > Databases and Data Analytics > Dell PowerStore: Oracle Best Practices > UDEV rules for LUNs
If ASMLib or ASMFD are not used to manage ASM disk persistence, udev must be used.
In our lab, we exposed raw NVMe LUNS to the database server and used udev rules to manage them. In the example below, udev rules appear to span multiple lines, but they do not. udev rules cannot span multiple lines as udev does not support any form of line continuation. There are five udev rules in the example. Each rule begins with token KERNEL.
KERNEL=="nvme*[0-9]n*[0-9]", SUBSYSTEM=="block", ENV{DEVTYPE}=="disk", ENV{ID_WWN}=="eui.119aee66b19fd8478ccf096800e757cf", SYMLINK+="oracleasm/ORA-ASM-CRS-01", OWNER="grid", GROUP="oinstall", MODE="0660"
KERNEL=="nvme*[0-9]n*[0-9]", SUBSYSTEM=="block", ENV{DEVTYPE}=="disk", ENV{ID_WWN}=="eui.5c26bf084208e48f8ccf096800a1797e", SYMLINK+="oracleasm/ORA-ASM-CRS-02", OWNER="grid", GROUP="oinstall", MODE="0660"
KERNEL=="nvme*[0-9]n*[0-9]", SUBSYSTEM=="block", ENV{DEVTYPE}=="disk", ENV{ID_WWN}=="eui.5f7f4857f9fd372f8ccf096800c83504", SYMLINK+="oracleasm/ORA-ASM-CRS-03", OWNER="grid", GROUP="oinstall", MODE="0660"
KERNEL=="nvme*[0-9]n*[0-9]", SUBSYSTEM=="block", ENV{DEVTYPE}=="disk", ENV{ID_WWN}=="eui.67a575ce1ad9c64c8ccf09680041d5c8", SYMLINK+="oracleasm/ORA-ASM-DATA-01", OWNER="grid", GROUP="oinstall", MODE="0660"
KERNEL=="nvme*[0-9]n*[0-9]", SUBSYSTEM=="block", ENV{DEVTYPE}=="disk", ENV{ID_WWN}=="eui.9a1fa26a642f902f8ccf096800a468c1", SYMLINK+="oracleasm/ORA-ASM-FRA-01", OWNER="grid", GROUP="oinstall", MODE="0660"
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Note: The ID_WWN values were derived from PowerStore Manager.
After the udev rules are defined, perform the following Linux commands to restart udev and use the rules.
udevadm control --reload-rules
udevadm trigger
After the udev rules have been triggered and NVMe volumes created in PowerStore and presented to the database server, the physical server can see the LUNs.