Use udev to manage asmdisk execution / sbin/scsi_id do not show UUID workaround 04/01 Update SLTechnology News&Howtos

Use udev to manage asmdisk execution / sbin/scsi_id do not show UUID workaround

2025-04-01 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > Database >

Shulou(Shulou.com)06/01 Report--

Today, when building RAC, we use udev method to create ASM disk. I don't know why I execute the / sbin/scsi_id command, but I can't get UUID, and the execution result doesn't show anything.

[root@seiang2] # scsi_id-u-g/dev/sdb

It seems impossible to configure the udevrules file without UUID. By consulting relevant materials, the partition information is obtained through the following two ways: udevinfo (version 6 operating system udevadm replaces udevinfo) command. You can use these two pieces of information in the partition SYSFS {start} = = "63" and SYSFS {size} = = "16771797" (version 6 becomes ATTR {start} = "4241160" and ATTR {size} = "2120580") to uniquely identify this device.

Experimental environment:

Operating system: Redhat5.5 Hostname:seiang2.comsys.com

Operating system: Redhat6.4 Hostname:test.comsys.com

First, use udevinfo/udevadm to obtain the unique identity of the partition

Add a new disk and partition it, and then use the udevinfo/udevadm command to obtain the unique identity of the partition

Redhat5 version

[root@seiang2~] # ll / sbin/udev*

-rwxr-xr-x1 root root 15176 May 5 2009/sbin/udevcontrol

-rwxr-xr-x1 root root 61864 May 5 2009/sbin/udevd

-rwxr-xr-x1 root root 8 × × 8 May 5 2009 / sbin/udevd.static

-rwxr-xr-x1 root root 23680 May 5 2009/sbin/udevsettle

-rwxr-xr-x1 root root 24144 May 5 2009/sbin/udevtrigger

[root@seiang2~] # cd/sys/block/sdb

[root@seiang2~] # udevinfo-a murp / sys/block/sdb

Udevinfostarts with the device specified by the devpath and then

Walksup the chain of parent devices. It prints for every device

Found,all possible attributes in the udev rules key format.

Arule to match, can be composed by the attributes of the device

Andthe attributes from one single parent device.

Looking at device'/ block/sdb':

KERNEL== "sdb"

SUBSYSTEM== "block"

SYSFS {stat} = "63 93 1248 19 000 0 19"

SYSFS {size} = "10485760"

SYSFS {removable} = = "0"

SYSFS {range} = = "16"

SYSFS {dev} = = "8:16"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1/target1:0:0/1:0:0:0':

ID== "1VOV 0VOUR 0UR 0"

BUS== "scsi"

DRIVER== "sd"

SYSFS {dh_state} = = "detached"

SYSFS {ioerr_cnt} = = "0x0"

SYSFS {iodone_cnt} = = "0x51"

SYSFS {iorequest_cnt} = = "0x51"

SYSFS {iocounterbits} = "32"

SYSFS {timeout} = = "60"

SYSFS {state} = = "running"

SYSFS {rev} = = "1.0"

SYSFS {model} = = "VBOX HARDDISK"

SYSFS {vendor} = = "ATA"

SYSFS {scsi_level} = = "6"

SYSFS {type} = = "0"

SYSFS {queue_type} = = "simple"

SYSFS {queue_depth} = "31"

SYSFS {device_blocked} = = "0"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1/target1:0:0':

ID== "target1:0:0"

BUS== ""

DRIVER== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1':

ID== "host1"

BUS== ""

DRIVER== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0':

ID== "0000:00:0d.0"

BUS== "pci"

DRIVER== "ahci"

SYSFS {broken_parity_status} = = "0"

SYSFS {enable} = = "1"

SYSFS {modalias} = = "pci:v00008086d00002829sv00000000sd00000000bc01sc06i01"

SYSFS {local_cpus} = "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"

SYSFS {irq} = "177"

SYSFS {class} = = "0x010601"

SYSFS {subsystem_device} = = "0x0000"

SYSFS {subsystem_vendor} = = "0x0000"

SYSFS {device} = = "0x2829"

SYSFS {vendor} = = "0x8086"

Looking at parent device'/ devices/pci0000:00':

ID== "pci0000:00"

BUS== ""

DRIVER== ""

[root@seiang2~] # fdisk/dev/sdb

Devicecontains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel

Buildinga new DOS disklabel. Changes will remain in memory only

Untilyou decide to write them. After that, of course, the previous

Contentwon't be recoverable.

Warning:invalid flag 0x0000 of partition table 4 will be corrected by w (rite)

Command (m for help): n

Commandaction

E extended

P primary partition (1-4)

Partitionnumber (1-4): 1

Firstcylinder (1,652, default 1):

Usingdefault value 1

Lastcylinder or + size or + sizeM or + sizeK (1,652, default 652): + 1G

Command (m for help): n

Commandaction

E extended

P primary partition (1-4)

Partitionnumber (1-4): 2

Firstcylinder (124,652, default):

Usingdefault value 124

Lastcylinder or + size or + sizeM or + sizeK: + 1G

Command (m for help): n

Commandaction

E extended

P primary partition (1-4)

Partitionnumber (1-4): 3

Firstcylinder (12652, default 126):

Usingdefault value 126

Lastcylinder or + size or + sizeM or + sizeK: + 1G

Command (m for help): P

Disk/dev/sdb: 5368 MB, 5368709120 bytes

255heads, 63 sectors/track, 652 cylinders

Units= cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/ dev/sdb1 1 123 987966 83 Linux

/ dev/sdb2 124 125 16065 83 Linux

/ dev/sdb3 126248987997 + 83 Linux

Command (m for help): W

Thepartition table has been altered!

Callingioctl () to re-read partition table.

Syncingdisks.

[root@seiang2~] # ll / dev/sdb*

Brw-r-1 root disk 8, 16 Jul 20 02:57 / dev/sdb

Brw-r-1 root disk 8, 17 Jul 20 02:57 / dev/sdb1

Brw-r-1 root disk 8, 18 Jul 20 02:57 / dev/sdb2

Brw-r-1 root disk 8, 19 Jul 20 02:57 / dev/sdb3

Use the udevinfo command to view detailed partition information

[root@seiang2~] # udevinfo-a murp / sys/block/sdb/sdb1

Udevinfostarts with the device specified by the devpath and then

Walksup the chain of parent devices. It prints for every device

Found,all possible attributes in the udev rules key format.

Arule to match, can be composed by the attributes of the device

Andthe attributes from one single parent device.

Looking at device'/ block/sdb/sdb1':

KERNEL== "sdb1"

SUBSYSTEM== "block"

SYSFS {stat} = "31 67 392 19 000 0 0 17 19"

SYSFS {size} = "1975932"

SYSFS {start} = "63"

SYSFS {dev} = = "8:17"

Looking at parent device'/ block/sdb':

ID== "sdb"

BUS== "block"

DRIVER== ""

SYSFS {stat} = "196575 3152 94 1 0 8 2 0 71 96"

SYSFS {size} = "10485760"

SYSFS {removable} = = "0"

SYSFS {range} = = "16"

SYSFS {dev} = = "8:16"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1/target1:0:0/1:0:0:0':

ID== "1VOV 0VOUR 0UR 0"

BUS== "scsi"

DRIVER== "sd"

SYSFS {dh_state} = = "detached"

SYSFS {ioerr_cnt} = = "0x0"

SYSFS {iodone_cnt} = = "0xe1"

SYSFS {iorequest_cnt} = = "0xe1"

SYSFS {iocounterbits} = "32"

SYSFS {timeout} = = "60"

SYSFS {state} = = "running"

SYSFS {rev} = = "1.0"

SYSFS {model} = = "VBOX HARDDISK"

SYSFS {vendor} = = "ATA"

SYSFS {scsi_level} = = "6"

SYSFS {type} = = "0"

SYSFS {queue_type} = = "simple"

SYSFS {queue_depth} = "31"

SYSFS {device_blocked} = = "0"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1/target1:0:0':

ID== "target1:0:0"

BUS== ""

DRIVER== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1':

ID== "host1"

BUS== ""

DRIVER== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0':

ID== "0000:00:0d.0"

BUS== "pci"

DRIVER== "ahci"

SYSFS {broken_parity_status} = = "0"

SYSFS {enable} = = "1"

SYSFS {modalias} = = "pci:v00008086d00002829sv00000000sd00000000bc01sc06i01"

SYSFS {local_cpus} = "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"

SYSFS {irq} = "177"

SYSFS {class} = = "0x010601"

SYSFS {subsystem_device} = = "0x0000"

SYSFS {subsystem_vendor} = = "0x0000"

SYSFS {device} = = "0x2829"

SYSFS {vendor} = = "0x8086"

Looking at parent device'/devices/pci0000:00':

ID== "pci0000:00"

BUS== ""

DRIVER== ""

[root@seiang2rules.d] # udevinfo-a-p / sys/block/sdb/sdb3/

Udevinfostarts with the device specified by the devpath and then

Walksup the chain of parent devices. It prints for every device

Found,all possible attributes in the udev rules key format.

Arule to match, can be composed by the attributes of the device

Andthe attributes from one single parent device.

Lookingat device'/ block/sdb/sdb3':

KERNEL== "sdb3"

SUBSYSTEM== "block"

SYSFS {stat} = "27 355 382 31 0 000 0 31"

SYSFS {size} = "1975995"

SYSFS {start} = "2008125"

SYSFS {dev} = = "8:19"

Looking at parent device'/ block/sdb':

ID== "sdb"

BUS== "block"

DRIVER== ""

SYSFS {stat} = "395 1754 5700 383 2 0 16 8 0 242 391"

SYSFS {size} = "10485760"

SYSFS {removable} = = "0"

SYSFS {range} = = "16"

SYSFS {dev} = = "8:16"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1/target1:0:0/1:0:0:0':

ID== "1VOV 0VOUR 0UR 0"

BUS== "scsi"

DRIVER== "sd"

SYSFS {dh_state} = = "detached"

SYSFS {ioerr_cnt} = = "0x0"

SYSFS {iodone_cnt} = = "0x1b3"

SYSFS {iorequest_cnt} = = "0x1b3"

SYSFS {iocounterbits} = "32"

SYSFS {timeout} = = "60"

SYSFS {state} = = "running"

SYSFS {rev} = = "1.0"

SYSFS {model} = = "VBOX HARDDISK"

SYSFS {vendor} = = "ATA"

SYSFS {scsi_level} = = "6"

SYSFS {type} = = "0"

SYSFS {queue_type} = = "simple"

SYSFS {queue_depth} = "31"

SYSFS {device_blocked} = = "0"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1/target1:0:0':

ID== "target1:0:0"

BUS== ""

DRIVER== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host1':

ID== "host1"

BUS== ""

DRIVER== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0':

ID== "0000:00:0d.0"

BUS== "pci"

DRIVER== "ahci"

SYSFS {broken_parity_status} = = "0"

SYSFS {enable} = = "1"

SYSFS {modalias} = = "pci:v00008086d00002829sv00000000sd00000000bc01sc06i01"

SYSFS {local_cpus} = "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"

SYSFS {irq} = "177"

SYSFS {class} = = "0x010601"

SYSFS {subsystem_device} = = "0x0000"

SYSFS {subsystem_vendor} = = "0x0000"

SYSFS {device} = = "0x2829"

SYSFS {vendor} = = "0x8086"

Looking at parent device'/devices/pci0000:00':

ID== "pci0000:00"

BUS== ""

DRIVER== ""

Edit the rule file for udev

[root@seiang2~] # cd/etc/udev/rules.d/

[root@seiang2rules.d] # vim99-oracle-asmdevices.rules

KERNEL== "sdb1", SUBSYSTEM== "block", SYSFS {size} = = "1975932", SYSFS {start} = = "63", OWNER= "grid", NAME= "asmdisk-data1", GROUP= "asmadmin", MODE= "0660"

KERNEL== "sdb3", SUBSYSTEM== "block", SYSFS {size} = = "1975995", SYSFS {start} = = "2008125", OWNER= "grid", NAME= "asmdisk-data2", GROUP= "asmadmin", MODE= "0660"

After editing the rule file, you can use udevtest to test udev for device management, naming, links, and permissions settings

[root@seiang2rules.d] # udevtest/block/sdb

Main:looking at device'/ block/sdb' from subsystem 'block'

Run_program:'/lib/udev/usb_id-X'

Run_program:'/lib/udev/usb_id' returned with status 1

Run_program:'/lib/udev/scsi_id-g-x-s / block/sdb-d / dev/.tmp-8-16'

Run_program:'/lib/udev/scsi_id' (stdout) 'ID_VENDOR=ATA'

Run_program:'/lib/udev/scsi_id' (stdout) 'ID_MODEL=VBOX_HARDDISK'

Run_program:'/lib/udev/scsi_id' (stdout) 'ID_REVISION=1.0'

Run_program:'/lib/udev/scsi_id' (stdout) 'ID_SERIAL=SATA_VBOX_HARDDISK_VBda65d90d-e2055c6a'

Run_program:'/lib/udev/scsi_id' (stdout) 'ID_TYPE=disk'

Run_program:'/lib/udev/scsi_id' (stdout) 'ID_BUS=scsi'

Run_program:'/lib/udev/scsi_id' returned with status 0

Udev_rules_get_name:add symlink 'disk/by-id/scsi-SATA_VBOX_HARDDISK_VBda65d90d-e2055c6a'

Run_program:'/lib/udev/path_id / block/sdb'

Run_program:'/lib/udev/path_id' (stdout) 'ID_PATH=pci-0000:00:0d.0-scsi-1:0:0:0'

Run_program:'/lib/udev/path_id' returned with status 0

Udev_rules_get_name:add symlink 'disk/by-path/pci-0000:00:0d.0-scsi-1:0:0:0'

Run_program:'/lib/udev/vol_id-- export / dev/.tmp-8-16'

Run_program:'/lib/udev/vol_id' returned with status 4

Run_program:'/lib/udev/edd_id-- export / dev/.tmp-8-16'

Run_program:'/lib/udev/edd_id' (stderr)'no kernel EDD support'

Run_program:'/lib/udev/edd_id' returned with status 2

Udev_rules_get_name:no node name set, will use kernel name 'sdb'

Udev_device_event:device'/ block/sdb' already in database, validate currently present symlinks

Udev_node_add:creating device node'/ dev/sdb', major = '813, minor =' 16, mode = '0640, uid=' 0, gid ='6'

Udev_node_add:creating symlink'/ dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBda65d90d-e2055c6a'to'.. /.. / sdb'

Udev_node_add:creating symlink'/ dev/disk/by-path/pci-0000:00:0d.0-scsi-1:0:0:0' to'../../sdb'

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/sdb / dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBda65d90d-e2055c6a/dev/disk/by-path/pci-0000:00:0d.0-scsi-1:0:0:0'

Restart udev, first use the command udevcontrol to reload rules before starting (this step can be omitted)

[root@seiang2rules.d] # udevcontrolreload_rules

[root@seiang2rules.d] # start_udev

Startingudev: [OK]

[root@seiang2rules.d] # ll/dev/asm*

Brw-rw----1 grid asmadmin 8, 17 Jul 20 03:09 / dev/asmdisk-data1

Brw-rw----1 grid asmadmin 8, 19 Jul 20 03:09 / dev/asmdisk-data2

[root@seiang2rules.d] #

Redhat6 version

[root@testrules.d] # udevadminfo-a-p / sys/block/sdb/sdb2

Udevadminfo starts with the device specified by the devpath and then

Walksup the chain of parent devices. It prints for every device

Found,all possible attributes in the udev rules key format.

Arule to match, can be composed by the attributes of the device

Andthe attributes from one single parent device.

Looking at device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0/block/sdb/sdb2':

KERNEL== "sdb2"

SUBSYSTEM== "block"

DRIVER== ""

ATTR {partition} = = "2"

ATTR {start} = "2120580"

ATTR {size} = "2120580"

ATTR {alignment_offset} = = "0"

ATTR {discard_alignment} = = "0"

ATTR {stat} = "238 84 1288 247 000 000 232 247"

ATTR {inflight} = = "0"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0/block/sdb':

KERNELS== "sdb"

SUBSYSTEMS== "block"

DRIVERS== ""

ATTRS {range} = = "16"

ATTRS {ext_range} = = "256"

ATTRS {removable} = = "0"

ATTRS {ro} = = "0"

ATTRS {size} = "10485760"

ATTRS {alignment_offset} = = "0"

ATTRS {discard_alignment} = = "0"

ATTRS {capability} = "52"

ATTRS {stat} = "2082 4734 15818 2580 98980 99628 48250 0 2549 50830"

ATTRS {inflight} = = "0"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0':

KERNELS== "3VOV 0VOUR 0UR 0"

SUBSYSTEMS== "scsi"

DRIVERS== "sd"

ATTRS {device_blocked} = = "0"

ATTRS {type} = = "0"

ATTRS {scsi_level} = = "6"

ATTRS {vendor} = = "ATA"

ATTRS {model} = = "VBOX HARDDISK"

ATTRS {rev} = = "1.0"

ATTRS {state} = = "running"

ATTRS {timeout} = = "30"

ATTRS {iocounterbits} = "32"

ATTRS {iorequest_cnt} = = "0xb10"

ATTRS {iodone_cnt} = = "0xb0e"

ATTRS {ioerr_cnt} = = "0xf"

ATTRS {modalias} = = "scsi:t-0x00"

ATTRS {evt_media_change} = = "0"

ATTRS {dh_state} = = "detached"

ATTRS {queue_depth} = "31"

ATTRS {queue_ramp_up_period} = "120000"

ATTRS {queue_type} = = "simple"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0':

KERNELS== "target3:0:0"

SUBSYSTEMS== "scsi"

DRIVERS== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3':

KERNELS== "host3"

SUBSYSTEMS== "scsi"

DRIVERS== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0':

KERNELS== "0000:00:0d.0"

SUBSYSTEMS== "pci"

DRIVERS== "ahci"

ATTRS {vendor} = = "0x8086"

ATTRS {device} = = "0x2829"

ATTRS {subsystem_vendor} = = "0x0000"

ATTRS {subsystem_device} = = "0x0000"

ATTRS {class} = = "0x010601"

ATTRS {irq} = "21"

ATTRS {local_cpus} = = "1"

ATTRS {local_cpulist} = = "0"

ATTRS {modalias} = = "pci:v00008086d00002829sv00000000sd00000000bc01sc06i01"

ATTRS {numa_node} = "- 1"

ATTRS {enable} = = "1"

ATTRS {broken_parity_status} = = "0"

ATTRS {msi_bus} = ""

Looking at parent device'/devices/pci0000:00':

KERNELS== "pci0000:00"

SUBSYSTEMS== ""

DRIVERS== ""

[root@testrules.d] # udevadminfo-a-p / sys/block/sdb/sdb3

Udevadminfo starts with the device specified by the devpath and then

Walksup the chain of parent devices. It prints for every device

Found,all possible attributes in the udev rules key format.

Arule to match, can be composed by the attributes of the device

Andthe attributes from one single parent device.

Looking at device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0/block/sdb/sdb3':

KERNEL== "sdb3"

SUBSYSTEM== "block"

DRIVER== ""

ATTR {partition} = = "3"

ATTR {start} = "4241160"

ATTR {size} = "2120580"

ATTR {alignment_offset} = = "0"

ATTR {discard_alignment} = = "0"

ATTR {stat} = "200 122 1288 255 00 00 0 250 255"

ATTR {inflight} = = "0"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0/block/sdb':

KERNELS== "sdb"

SUBSYSTEMS== "block"

DRIVERS== ""

ATTRS {range} = = "16"

ATTRS {ext_range} = = "256"

ATTRS {removable} = = "0"

ATTRS {ro} = = "0"

ATTRS {size} = "10485760"

ATTRS {alignment_offset} = = "0"

ATTRS {discard_alignment} = = "0"

ATTRS {capability} = "52"

ATTRS {stat} = "2082 4734 15818 2580 98980 99628 48250 0 2549 50830"

ATTRS {inflight} = = "0"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0':

KERNELS== "3VOV 0VOUR 0UR 0"

SUBSYSTEMS== "scsi"

DRIVERS== "sd"

ATTRS {device_blocked} = = "0"

ATTRS {type} = = "0"

ATTRS {scsi_level} = = "6"

ATTRS {vendor} = = "ATA"

ATTRS {model} = = "VBOX HARDDISK"

ATTRS {rev} = = "1.0"

ATTRS {state} = = "running"

ATTRS {timeout} = = "30"

ATTRS {iocounterbits} = "32"

ATTRS {iorequest_cnt} = = "0xb10"

ATTRS {iodone_cnt} = = "0xb0e"

ATTRS {ioerr_cnt} = = "0xf"

ATTRS {modalias} = = "scsi:t-0x00"

ATTRS {evt_media_change} = = "0"

ATTRS {dh_state} = = "detached"

ATTRS {queue_depth} = "31"

ATTRS {queue_ramp_up_period} = "120000"

ATTRS {queue_type} = = "simple"

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0':

KERNELS== "target3:0:0"

SUBSYSTEMS== "scsi"

DRIVERS== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3':

KERNELS== "host3"

SUBSYSTEMS== "scsi"

DRIVERS== ""

Looking at parent device'/devices/pci0000:00/0000:00:0d.0':

KERNELS== "0000:00:0d.0"

SUBSYSTEMS== "pci"

DRIVERS== "ahci"

ATTRS {vendor} = = "0x8086"

ATTRS {device} = = "0x2829"

ATTRS {subsystem_vendor} = = "0x0000"

ATTRS {subsystem_device} = = "0x0000"

ATTRS {class} = = "0x010601"

ATTRS {irq} = "21"

ATTRS {local_cpus} = = "1"

ATTRS {local_cpulist} = = "0"

ATTRS {modalias} = = "pci:v00008086d00002829sv00000000sd00000000bc01sc06i01"

ATTRS {numa_node} = "- 1"

ATTRS {enable} = = "1"

ATTRS {broken_parity_status} = = "0"

ATTRS {msi_bus} = ""

Looking at parent device'/devices/pci0000:00':

KERNELS== "pci0000:00"

SUBSYSTEMS== ""

DRIVERS== ""

[root@testrules.d] # vim99-oracle-asmdevices.rules

KERNEL== "sdb2", SUBSYSTEM== "block", ATTR {size} = = "2120580", ATTR {start} = = "2120580", OWNER= "grid", NAME= "asmdisk-data1", GROUP= "asmadmin", MODE= "0660"

KERNEL== "sdb3", SUBSYSTEM== "block", ATTR {size} = = "2120580", ATTR {start} = = "4241160", OWNER= "grid", NAME= "asmdisk-data2", GROUP= "asmadmin", MODE= "0660"

[root@testrules.d] # start_udev

Startingudev: [OK]

[root@testrules.d] # ll/dev/asm*

Brw-rw----.1 grid asmadmin 8, 18 Jul 20 15:57 / dev/asmdisk-data1

Brw-rw----.1 grid asmadmin 8, 19 Jul 20 15:57 / dev/asmdisk-data2

Use bare devices to create asm disks

Add a new disk and partition it

[root@seiang2rules.d] # fdisk / dev/sdb

Command (m for help): n

Commandaction

E extended

P primary partition (1-4)

Selectedpartition 4

Firstcylinder (249652, default 249):

Usingdefault value 249

Lastcylinder or + size or + sizeM or + sizeK (249652, default 652):

Usingdefault value 652

Command (m for help): n

Firstcylinder (249652, default 249):

Usingdefault value 249

Lastcylinder or + size or + sizeM or + sizeK (249652, default 652): + 1G

Command (m for help): n

Firstcylinder (37262, default 372):

Usingdefault value 372

Lastcylinder or + size or + sizeM or + sizeK: + 1G

Command (m for help): W

Thepartition table has been altered!

Callingioctl () to re-read partition table.

Syncingdisks.

[root@seiang2rules.d] # fdisk-l

Disk/dev/sda: 16.1 GB, 16106127360 bytes

255heads, 63 sectors/track, 1958 cylinders

Units= cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/ dev/sda1 * 1 13 104391 83 Linux

/ dev/sda2 14 1958 15623212 + 8e Linux LVM

Disk/dev/sdb: 5368 MB, 5368709120 bytes

255heads, 63 sectors/track, 652 cylinders

Units= cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/ dev/sdb1 1 123 987966 83 Linux

/ dev/sdb2 124 125 16065 83 Linux

/ dev/sdb3 126248987997 + 83 Linux

/ dev/sdb4 249 652 3245130 5 Extended

/ dev/sdb5 249 371 987966 83 Linux

/ dev/sdb6 372 494 987966 83 Linux

Configure bare device mapping, modify / etc/udev/rules.d/60-raw.rules file

[root@seiang2rules.d] # vim60-raw.rules

ACTION== "add", KERNEL== "/ dev/sdb5", RUN+= "/ bin/raw / dev/raw/raw5% N"

ACTION== "add", ENV {MAJOR} = = "8", ENV {MINOR} = = "1", RUN+= "/ bin/raw/dev/raw/raw5% M% m"

ACTION== "add", KERNEL== "/ dev/sdb6", RUN+= "/ bin/raw / dev/raw/raw6% N"

ACTION== "add", ENV {MAJOR} = = "8", ENV {MINOR} = = "2", RUN+= "/ bin/raw/dev/raw/raw6% M% m"

ACTION== "add", KERNEL== "raw5", OWNER= "grid", GROUP= "asmadmin", MODE= "0660"

ACTION== "add", KERNEL== "raw6", OWNER= "grid", GROUP= "asmadmin", MODE= "0660"

Restart the udev service and query raw

[root@seiang2rules.d] # start_udev

Startingudev: [OK]

[root@seiang2rules.d] # raw-qa

/ dev/raw/raw5: bound to major 8, minor 1

/ dev/raw/raw6: bound to major 8, minor 2

[root@seiang2rules.d] # ll/dev/raw*

Crw-1 root root 162, 0 Jul 20 02:53 / dev/rawctl

/ dev/raw:

Total0

Crw-rw---- 1 gridasmadmin 162, 5 Jul 20 03:31 raw5

Crw-rw---- 1 gridasmadmin 162, 6 Jul 20 03:31 raw6

Introduction to bare Devices (from http://blog.itpub.net/26736162/viewspace-1401193/)

Bare device: also known as bare partition (raw partition), is a special character device that is not formatted and is not read by Unix/Linux through the file system. Bare devices can be bound to either a partition or a disk.

Character device: reading and writing to character device does not need to go through OS's buffer. It cannot be used by the file system mount.

Block devices: read and write to block devices need to go through OS's buffer, which can be mount to the file system.

This is related to the version of linux. In the old version, you can only have up to 256bare devices. Under Linux 4, you can bind 81Array2 bare devices by doing more. However, under linux, there can only be a maximum of 255partitions, so if you bind a partition with a bare device, you can only bind a maximum of 255bare devices. If you are using lvm, there is no such restriction.

There can be up to 15 partitions on a single disk under Linux. 3 primary partitions + 1 extended partition + 11 logical partitions.

The proposed partition method is to first divide into 3 primary partitions, the fourth partition is an extended partition, and then divide it into 11 logical partitions in the extended partition.

Note: bare devices should not be bound to extended partitions. If you need to use bare devices in linux, you need to bind them manually, but not in unix.

Major and minor devicenumber

In the unix/linux system, everything is a file. All hard drives, keyboards and other devices are represented by files, corresponding to the files under / dev. For applications, you can open, close, read and write these device files just like ordinary files. But such filenames, such as / dev/sda and / dev/ raw/raw1, are user space names, and OS Kernel has no idea what the name refers to. In kernel space, devices are distinguished by major and minor devicenumber.

Major devicenumber can be thought of as a device driver, and devices managed by the same device driver have the same major devicenumber. This number is actually the index of device drivertable in Kernel, and this table holds different device drivers. Minor devicenumber is used to represent the specific device being accessed. In other words, Kernel finds the device driver based on major devicenumber, and then obtains attributes such as device location from minor devicenumber. All of these major devicenumber are pre-assigned. For example, the bare device is 162 and the SCSI block device is 8.

The configuration of raw devices on the Redhat platform has changed since redhat 5. Prior to redhat 5, / etc/sysconfig/rawdevices components were configured directly, and / etc/init.d/rawdevices was used to manage the startup and shutdown of raw devices. After Redhat 5, the original raw device interface has been cancelled, and redhat 5 is configured through udev rules. To configure, you need to edit the file / etc/udev/rules.d/60-raw.rules.

Cat/etc/udev/rules.d/60-raw.rules

# Enter raw device bindings here.

# An example would be:

# ACTION== "add", KERNEL== "sda", RUN+= "/ bin/raw / dev/raw/raw1% N"

# to bind / dev/raw/raw1 to / dev/sda, or

# ACTION== "add", ENV {MAJOR} = = "8", ENV {MINOR} = = "1", RUN+= "/ bin/raw / dev/raw/raw2% M% m"

# to bind / dev/raw/raw2 to the device with major 8, minor 1.

Among them

ACTION== "add", KERNEL= "", RUN+= "raw/ dev/raw/rawX%N"

Configure the device name and replace it with the device name you need to bind (e.g. / dev/sda1). X is the naked device number.

Primary / minor number:

ACTION== "add", ENV {MAJOR} = "A", ENV {MINOR} = "B", RUN+= "raw/ dev/raw/rawX M% m"

"A" and "B" are the primary / secondary numbers of the device, and X is the raw device number used by the system.

The personal understanding of the process of redhat managing raw is that in redhat 5, raw devices are managed through udev, while udev identifies raw devices through MAJOR and MINOR. Therefore, it is necessary to bind the device number and the bare equipment number, and the primary and secondary equipment numbers can be specified or assigned automatically by the system. According to the example of raw.rule in red hat's official documentation, KERNEL==.. Or ENV {MAJOR}... You only need to configure one at will, but some netizens have tested and verified that they must be configured at the same time.

If you have more than one raw device, you can write as follows:

ACTION== "add", KERNEL== "raw [1-4]", OWNER= "dave", GROUP= "tianlesoftware", MODE= "0660"

Note: use / etc/sysconfig/rawdevices and / etc/udev/permissions.d/50-udev.permissions for raw device configuration and rights management prior to kernel 2.6.9-89.5AXS2. After kernel 2.6.18-128.7AXS3, the / etc/udev/rules.d/60-raw.rules introduced in this article is used to manage raw devices.

Considerations for using bare devices as data files for Oracle

1. A bare device can only place one data file.

2. The size of the data file cannot exceed the size of the bare device.

If it is a log file, the maximum available size of the bare device = the partition size corresponding to the bare device-1 * 512 (keep one redo lock)

If it is a data file, the maximum available size of the bare device = the partition size corresponding to the bare device-2 * db_block_size (two block reserved)

For simplicity, set all files to be 1m smaller than the bare device.

3. It is best not to set the data file to be called automatic extension. If the setting is called automatic extension, be sure to set the maxsize setting to be smaller than the bare device.

4. Oracle under linux cannot directly use logical volumes as bare devices, but also binds them. Not under unix.