UDEV SCSI Rules Configuration for ASM in Oracle Linux 5 and 6

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UDEV SCSI Rules Configuration for ASM in Oracle Linux 5 and 6

　　For Oracle Automatic Storage Manager (ASM) to use disks, it needs to be able to>

• 　　Background
  
• 　　Identify the Disks (/sbin/scsi_id)
  
• 　　Make SCSI Devices Trusted
  
• 　　Create UDEV Rules File
  
• 　　Load Updated Block Device Partitions (/sbin/partprobe)
  
• 　　Test Rules (udevtest)
  
• 　　Restart UDEV Service
  
• 　　Check Ownership and Permissions
  

Background

　　Essentially, what udev does is apply rules defined in files in the "/etc/udev/rules.d" directory to the device nodes listed in the "/dev" directory. The rules can be defined in a variety of ways, but what we need to do is>
　　In this case I know all my disk devices are named "/dev/sd?1", where the "?" represents a letter from a-d, so I can>KERNEL=="sd?1", BUS=="scsi"
　　I want to tie each specific device to an alias, so it is always>PROGRAM=="/sbin/scsi_id -g -u -s /block/$parent", RESULT=="SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_"　　The scsi_id command works a little differently in Oracle Linux 6, so for that the following test works better.
PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_"
　　Once we have>NAME="asm-disk1", OWNER="oracle", GROUP="dba", MODE="0660"　　So the whole rule for each disk will look something like this in Oracle Linux 5.
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -s /block/$parent", RESULT=="SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_", NAME="asm-disk1", OWNER="oracle", GROUP="dba", MODE="0660"　　Or this in Oracle Linux 6.
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_", NAME="asm-disk1", OWNER="oracle", GROUP="dba", MODE="0660"
　　This means that the device pointing to the partition "sd*1" on the disk with the SCSI>　　There are a number of wildcards and matching patterns that can be used if you don't want to write device-specific rules.
　　Now we know roughly what we are trying to achieve, we will look at each step necessary for setting up the disks for ASM to use.
Identify the Disks (/sbin/scsi_id)

　　We are going to write device-specific rules, so we need to be able to>scsi_id command. The "-s" option makes the paths># /sbin/scsi_id -g -u -s /block/sdb　　
SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_
　　
# /sbin/scsi_id -g -u -s /block/sdc
　　
SATA_VBOX_HARDDISK_VB46dec7e0-192e8000_
　　
# /sbin/scsi_id -g -u -s /block/sdd
　　
SATA_VBOX_HARDDISK_VBce8c63bb-ac67a172_
　　
# /sbin/scsi_id -g -u -s /block/sde
　　
SATA_VBOX_HARDDISK_VB7437a3b7-95b199cd_
　　
#
　　The "-s" is not available in Oracle Linux 6, so you must use the following syntax.
# /sbin/scsi_id -g -u -d /dev/sdb　　
SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_
　　
# /sbin/scsi_id -g -u -d /dev/sdc
　　
SATA_VBOX_HARDDISK_VB46dec7e0-192e8000_
　　
# /sbin/scsi_id -g -u -d /dev/sdd
　　
SATA_VBOX_HARDDISK_VBce8c63bb-ac67a172_
　　
# /sbin/scsi_id -g -u -d /dev/sde
　　
SATA_VBOX_HARDDISK_VB7437a3b7-95b199cd_
　　
#
Make SCSI Devices Trusted
　　Add the following to the "/etc/scsi_id.config" file to configure SCSI devices as trusted. Create the file if it doesn't already exist.
options=-gCreate UDEV Rules File
　　Create the "/etc/udev/rules.d/99-oracle-asmdevices.rules" file.
# vi /etc/udev/rules.d/99-oracle-asmdevices.rules　　The file should contain the following lines for Oracle Linux 5. The PROGRAM parameter must match the command you used to retrieve the SCSI>RESULT parameter must match the value returned from your disks.
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -s /block/$parent", RESULT=="SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_", NAME="asm-disk1", OWNER="oracle", GROUP="dba", MODE="0660"　　
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -s /block/$parent", RESULT=="SATA_VBOX_HARDDISK_VB46dec7e0-192e8000_", NAME="asm-disk2", OWNER="oracle", GROUP="dba", MODE="0660"
　　
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -s /block/$parent", RESULT=="SATA_VBOX_HARDDISK_VBce8c63bb-ac67a172_", NAME="asm-disk3", OWNER="oracle", GROUP="dba", MODE="0660"
　　
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -s /block/$parent", RESULT=="SATA_VBOX_HARDDISK_VB7437a3b7-95b199cd_", NAME="asm-disk4", OWNER="oracle", GROUP="dba", MODE="0660"
　　The equivalent for Oracle Linux 6 is shown below.
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_", NAME="asm-disk1", OWNER="oracle", GROUP="dba", MODE="0660"　　
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="SATA_VBOX_HARDDISK_VB46dec7e0-192e8000_", NAME="asm-disk2", OWNER="oracle", GROUP="dba", MODE="0660"
　　
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="SATA_VBOX_HARDDISK_VBce8c63bb-ac67a172_", NAME="asm-disk3", OWNER="oracle", GROUP="dba", MODE="0660"
　　
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="SATA_VBOX_HARDDISK_VB7437a3b7-95b199cd_", NAME="asm-disk4", OWNER="oracle", GROUP="dba", MODE="0660"
Load Updated Block Device Partitions (/sbin/partprobe)
　　Load updated block device partition tables.
# /sbin/partprobe /dev/sdb1　　
# /sbin/partprobe /dev/sdc1
　　
# /sbin/partprobe /dev/sdd1
　　
# /sbin/partprobe /dev/sde1
Test Rules (udevtest)
　　Test the rules are working as expected.
# #OL5　　
# udevtest /block/sdb/sdb1
　　
# udevtest /block/sdc/sdc1
　　
# udevtest /block/sdd/sdd1
　　
# udevtest /block/sde/sde1
　　

　　
# #OL6
　　
# udevadm test /block/sdb/sdb1
　　
# udevadm test /block/sdc/sdc1
　　
# udevadm test /block/sdd/sdd1
　　
# udevadm test /block/sde/sde1
　　The output from the first disk should look something like this.
# udevtest /block/sdb/sdb1　　
main: looking at device '/block/sdb/sdb1' from subsystem 'block'
　　
udev_rules_get_name: add symlink 'disk/by-id/scsi-SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3-part1'
　　
udev_rules_get_name: add symlink 'disk/by-path/pci-0000:00:0d.0-scsi-1:0:0:0-part1'
　　
run_program: '/lib/udev/vol_id --export /dev/.tmp-8-17'
　　
run_program: '/lib/udev/vol_id' returned with status 4
　　
run_program: '/sbin/scsi_id -g -u -s /block/sdb/sdb1'
　　
run_program: '/sbin/scsi_id' (stdout) 'SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3_'
　　
run_program: '/sbin/scsi_id' returned with status 0
　　
udev_rules_get_name: rule applied, 'sdb1' becomes 'asm-disk1'
　　
udev_device_event: device '/block/sdb/sdb1' already in database, validate currently present symlinks
　　
udev_node_add: creating device node '/dev/asm-disk1', major = '8', minor = '17', mode = '0660', uid = '1100', gid = '1200'
　　
udev_node_add: creating symlink '/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3-part1' to '../../asm-disk1'
　　
udev_node_add: creating symlink '/dev/disk/by-path/pci-0000:00:0d.0-scsi-1:0:0:0-part1' to '../../asm-disk1'
　　
main: run: 'socket:/org/kernel/dm/multipath_event'
　　
main: run: 'socket:/org/kernel/udev/monitor'
　　
main: run: '/lib/udev/udev_run_devd'
　　
main: run: 'socket:/org/freedesktop/hal/udev_event'
　　
main: run: '/sbin/pam_console_apply /dev/asm-disk1 /dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBd306dbe0-df3367e3-part1 /dev/disk/by-path/pci-0000:00:0d.0-scsi-1:0:0:0-part1'
　　
#
Restart UDEV Service
　　Restart the UDEV service.
# #OL5　　
# /sbin/udevcontrol reload_rules
　　

　　
# #OL6
　　
# udevadm control --reload-rules
　　

　　
# #OL5 and OL6
　　
# /sbin/start_udev
Check Ownership and Permissions
　　Check the disks are now available with the "asm-disk*" alias and the correct ownership and permissions.
# cd /dev　　
# ls -al asm-disk*
　　
brw-rw---- 1 oracle dba 8, 17 Apr  8 22:47 asm-disk1
　　
brw-rw---- 1 oracle dba 8, 33 Apr  8 22:47 asm-disk2
　　
brw-rw---- 1 oracle dba 8, 49 Apr  8 22:47 asm-disk3
　　
brw-rw---- 1 oracle dba 8, 65 Apr  8 22:47 asm-disk4
　　
#

　　So the ASM_DISKSTRING initialization parameter in the ASM instance can be set to '/dev/asm-disk*' to>　　For more information see:

• 　　udev
  
• 　　Configuring Disk Devices Manually for Oracle ASM
  

　　Hope this helps. Regards Tim...