Tested Environment
- OEL 6.4 with RAC 11.2.0.4
Key Facts
- Don’t use /dev/sdX or /dev/dm-XX as device name as this device names can change after a reboot
- Use the WWID for identifying devices
- The World Wide Identifier (WWID) can be used to reliably identifying disk devices.
- WWID is a persistent, system-independent ID that the SCSI Standard requires from all SCSI devices.
Display all available WWID on your system
Shell script to display WWID on your system #!/bin/bash # #Usage: As root user run : ./check_wwid.sh # for FILE in `find /dev -name "sd*" | sort` do WWID=`scsi_id --whitelisted --replace-whitespace --device=$FILE ` echo $FILE " WWID: " $WWID done $ sudo ./check_wwid.sh .. /dev/sdb WWID: 1ATA_VBOX_HARDDISK_VB81c4f844-94203a15 /dev/sdb1 WWID: 1ATA_VBOX_HARDDISK_VB81c4f844-94203a15 /dev/sdc WWID: 1ATA_VBOX_HARDDISK_VB2ed83c09-e66dbcfb /dev/sdc1 WWID: 1ATA_VBOX_HARDDISK_VB2ed83c09-e66dbcfb .. --> Of course WWIDs for partitions and for the complete disk are identical
Create UDEV for a WWID identified SCSI device
- Note in this sample we only change owner, group and protection for a disk device /dev/sdX
# cat 99-oracle-asmdevices.rules KERNEL=="sd*", SUBSYSTEM=="block", ENV{DEVTYPE}=="disk", ENV{ID_SERIAL}=="14f504e46494c45523264556151442d5261336d2d566e4250", OWNER="grid", GROUP="asmadmin", MODE="0660" # ls -ls /dev/sdr 0 brw-rw----. 1 grid asmadmin 65, 16 Mar 19 14:42 /dev/sdr Reload and Restart the udev rules # udevadm control --reload-rules # start_udev Starting udev: [ OK ] Verify disk protections: # ls -ltr /dev/asm* brw-rw----. 1 grid asmadmin 8, 17 Mar 15 10:03 /dev/asmdisk1_udev_sdb1 brw-rw----. 1 grid asmadmin 8, 33 Mar 15 10:03 /dev/asmdisk2_udev_sdc1 Redistribute 99-oracle-asmdevices.rules file to all cluster nodes and restat udev echo system on these nodes # scp 99-oracle-asmdevices.rules grac42:/etc/udev/rules.d # scp 99-oracle-asmdevices.rules grac43:/etc/udev/rules.d On each RAC node # udevadm control --reload-rules # start_udev # ls -ltr /dev/asm* brw-rw----. 1 grid asmadmin 8, 17 Mar 15 10:03 /dev/asmdisk1_udev_sdb1 brw-rw----. 1 grid asmadmin 8, 33 Mar 15 10:03 /dev/asmdisk2_udev_sdc1
UDev rules for a disk partition using /sbin/scsi_id ( prefered mothode as we can change the NAME )
- Note this sample maps: /dev/sdb1 to /dev/asmdisk1_udev_sdb1, …
# cat 99-oracle-asmdevices.rules KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="1ATA_VBOX_HARDDISK_VB81c4f844-94203a15", NAME= "asmdisk1_udev_sdb1", OWNER="grid", GROUP="asmadmin", MODE="0660" KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="1ATA_VBOX_HARDDISK_VB2ed83c09-e66dbcfb", NAME= "asmdisk1_udev_sdc1", OWNER="grid", GROUP="asmadmin", MODE="0660" # ls -l /dev/asmdisk1_udev_sdb1 /dev/asmdisk1_udev_sdc1 brw-rw----. 1 grid asmadmin 8, 17 Mar 19 13:53 /dev/asmdisk1_udev_sdb1 brw-rw----. 1 grid asmadmin 8, 33 Mar 19 13:53 /dev/asmdisk1_udev_sdc1
Reference:
- How To Setup Partitioned Linux Block Devices Using UDEV (Non-ASMLIB) And Assign Them To ASM? (Doc ID 1528148.1)
