今天在搭建RAC的時候，使用udev方式來創建ASM磁盤，執行/sbin/scsi_id命令不知道啥原因,死活獲取不到UUID,執行結果啥也不顯示。
[root@seiang2 ~]# scsi_id -u -g/dev/sdb
沒有UUID貌似沒法配置udevrules文件，通過查閱相關資料，通過如下兩種方式實現的,通過udevinfo（6版本操作系統udevadm取代了udevinfo）命令獲取分區的信息,可以利用分區中的這2項信息SYSFS{start}=="63"和SYSFS{size}=="16771797"（6版本變爲ATTR{start}=="4241160"和ATTR{size}=="2120580"）來代替uuid唯一標識這個設備；
實驗環境：
操作系統：Redhat5.5 Hostname：seiang2.comsys.com
操作系統：Redhat6.4 Hostname：test.comsys.com
一、使用udevinfo/udevadm獲取分區的唯一標識
新增加一塊磁盤，並對它進行分區，分區之後通過udevinfo/udevadm命令來獲取分區的唯一標識；
Redhat5版本
[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 899928 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-p /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 0 0 0 0 0 19 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=="1:0:0:0"
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}=="00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000"
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)
p
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)
p
Partitionnumber (1-4): 2
Firstcylinder (124-652, default 124):
Usingdefault value 124
Lastcylinder or +size or +sizeM or +sizeK (124-652, default 652): +1G
Command(m for help): n
Commandaction
e extended
p primary partition (1-4)
p
Partitionnumber (1-4): 3
Firstcylinder (126-652, default 126):
Usingdefault value 126
Lastcylinder or +size or +sizeM or +sizeK (126-652, default 652): +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 126 248 987997+ 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
使用udevinfo命令查看詳細的分區信息
[root@seiang2~]# udevinfo -a-p /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 0 0 0 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}==" 196 575 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=="1:0:0:0"
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}=="00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000"
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==""
[[email protected]]#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 0 0 0 0 31 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=="1:0:0:0"
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}=="00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000"
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==""
編輯udev的rule文件
[root@seiang2~]# cd/etc/udev/rules.d/
[[email protected]]# 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"
編輯rule文件之後可以使用udevtest測試udev對設備的管理,命名,鏈接以及權限的設置情況
[[email protected]]# 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 = '8', 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'
重新啓動udev,在啓動之前首先使用命令udevcontrol重新裝載rules（此步驟可以省略）
[[email protected]]# udevcontrolreload_rules
[[email protected]]# start_udev
Startingudev: [ OK ]
[[email protected]]# 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
Redhat6版本
[[email protected]]# 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 0 0 0 0 0 232 247"
ATTR{inflight}==" 0 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 640 98980 99628 48250 0 2549 50830"
ATTRS{inflight}==" 0 0"
looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0':
KERNELS=="3:0:0:0"
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==""
[[email protected]]# 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 0 0 0 0 0 250 255"
ATTR{inflight}==" 0 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 640 98980 99628 48250 0 2549 50830"
ATTRS{inflight}==" 0 0"
looking at parent device'/devices/pci0000:00/0000:00:0d.0/host3/target3:0:0/3:0:0:0':
KERNELS=="3:0:0:0"
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==""
[[email protected]]# 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"
[[email protected]]# start_udev
Startingudev: [ OK ]
[[email protected]]# 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
二、使用裸設備創建asm磁盤
新增加一塊磁盤，並對其進行分區；
[[email protected]]# fdisk /dev/sdb
Command(m for help): n
Commandaction
e extended
p primary partition (1-4)
e
Selectedpartition 4
Firstcylinder (249-652, default 249):
Usingdefault value 249
Lastcylinder or +size or +sizeM or +sizeK (249-652, default 652):
Usingdefault value 652
Command(m for help): n
Firstcylinder (249-652, default 249):
Usingdefault value 249
Lastcylinder or +size or +sizeM or +sizeK (249-652, default 652): +1G
Command(m for help): n
Firstcylinder (372-652, default 372):
Usingdefault value 372
Lastcylinder or +size or +sizeM or +sizeK (372-652, default 652): +1G
Command(m for help): w
Thepartition table has been altered!
Callingioctl() to re-read partition table.
Syncingdisks.
[[email protected]]# 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 126 248 987997+ 83 Linux
/dev/sdb4 249 652 3245130 5 Extended
/dev/sdb5 249 371 987966 83 Linux
/dev/sdb6 372 494 987966 83 Linux
配置裸設備映射，修改/etc/udev/rules.d/60-raw.rules文件
[[email protected]]# 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"
重啓udev服務，並查詢raw
[[email protected]]# start_udev
Startingudev: [ OK ]
[[email protected]]# raw-qa
/dev/raw/raw5: bound to major 8, minor 1
/dev/raw/raw6: bound to major 8, minor 2
[[email protected]]# 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
裸設備介紹 (來自http://blog.itpub.net/26736162/viewspace-1401193/)
裸設備：也叫裸分區（原始分區），是一種沒有經過格式化，不被Unix/Linux通過文件系統來讀取的特殊字符設備。裸設備可以綁定一個分區，也可以綁定一個磁盤。
字符設備：對字符設備的讀寫不需要通過OS的buffer。它不可被文件系統mount。
塊設備：對塊設備的讀寫需要通過OS的buffer，它可以被mount到文件系統中。
這個與linux的版本相關，在舊版本中，最多只可以有256個裸設備，Linux 4下做多可以綁定81Array2個裸設備。但是在linux下，最多只能有255個分區，所以，如果用裸設備綁定分區，最多隻能綁定255個裸設備。如果是用lvm，則沒有這個限制。
Linux下單個磁盤最多可以有15個分區。3個主分區 + 1個擴展分區 + 11個邏輯分區。
建議的分區方法是：先分3個主分區，第四個分區爲擴展分區，然後在擴展分區中再分成11個邏輯分區。
注意:裸設備不要綁定在擴展分區上。 linux下如果需要使用裸設備，則需要手工進行綁定，unix下則不用。
major和minor devicenumber
在unix/linux系統中，一切都是文件。所有硬盤、鍵盤等設備都用文件來代表，對應着/dev下面的文件。對於應用程序來說，可以像對待普通文件一樣打開，關閉、讀寫這些設備文件。但是這種文件名，比如/dev/sda、/dev /raw/raw1都是用戶空間名稱，OS Kernel根本不知道這個名稱指的是什麼。在內核空間是通過major、minor devicenumber 來區分設備的。
major device number可以看作是設備驅動程序，被同一設備驅動程序管理的設備有相同的major devicenumber。這個數字實際是Kernel中device drivertable 的索引，這個表保存着不同設備驅動程序。而minor devicenumber用來代表被訪問的具體設備。也就是說Kernel根據major devicenumber 找到設備驅動程序，然後再從minor devicenumber 獲得設備位置等屬性。所有這些major devicenumber 是已經預先分配好的。比如裸設備是162，scsi塊設備是8
Redhat平臺對raw設備的配置在redhat 5之後有了變化。在redhat 5之前，直接配置/etc/sysconfig/rawdevices件，通過/etc/init.d/rawdevices來管理raw設備的啓動和關閉。在Redhat 5之後，原來的raw設備接口已經取消了，redhat 5中通過udev規則進行配置。要配置，需要編輯/etc/udev/rules.d/60-raw.rules這個文件。
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.
其中
ACTION=="add", KERNEL="", RUN+="raw /dev/raw/rawX%N"
配置設備名稱，用你需要綁定的設備名稱替換（如：/dev/sda1），X爲裸設備號
主/次號碼：
ACTION=="add", ENV{MAJOR}="A",ENV{MINOR}="B", RUN+="raw /dev/raw/rawX %M %m"
"A" 和 "B" 是設備的主/次號碼，X是系統使用的raw設備號碼。
個人對redhat管理raw的過程理解爲：在redhat 5中，是通過udev來管理raw設備的，而udev是通過 MAJOR和MINOR來識別 raw設備。故需要將設備號和裸設備號進行綁定，而主設備號和次設備號可以自行指定或者由系統自動分配。根據red hat的官方文檔中關於raw.rule的示例中說KERNEL==..或ENV{MAJOR}...只需要任意配置一個就可以，但有些網友經過試驗，驗證必須二者同時配置纔可以。
如果有多個raw設備，可以寫成：
ACTION=="add", KERNEL=="raw[1-4]",OWNER="dave", GROUP="tianlesoftware", MODE="0660"
注意：在內核2.6.9-89.5AXS2之前使用/etc/sysconfig/rawdevices和/etc/udev/permissions.d/50-udev.permissions進行raw設備的配置和權限管理。在內核 2.6.18-128.7AXS3以後則使用了本文介紹的 /etc/udev/rules.d/60-raw.rules進行raw設備的管理
使用裸設備作爲Oracle的數據文件的注意事項
1、一個裸設備只能放置一個數據文件
2、數據文件的大小不能超過裸設備的大小
如果是日誌文件，則裸設備最大可用大小=裸設備對應分區大小 - 1 * 512 （保留一個redo lock）
如果是數據文件，則裸設備最大可用大小=裸設備對應分區大小 - 2 *db_block_size（保留兩個block）
爲了簡單起見，對所有的文件設置稱比裸設備小1M即可。
3、數據文件最好不要設置稱自動擴展，如果設置稱自動擴展，一定要把maxsize設置設置爲比裸設備小
4、linux下oracle不能直接把邏輯卷作爲裸設備，也要進行綁定。unix下就不需要。
相關鏈接：
http://blog.itpub.net/14184018/viewspace-701675/
http://blog.itpub.net/14184018/viewspace-1364944/
作者：SEian.G（苦練七十二變，笑對八十一難）
ITPUB：http://blog.itpub.net/31015730/
51CTO：http://seiang.blog.51cto.com/