start_udev 是不是会写磁盘头
遇到一个案例，在这里记录一下
一套Oracle 11.2.0.4 RAC环境，操作系统是RHEL 6.5，共享磁盘是通过UDEV实现RAW绑定设备名，如下
[root@rac1 opt]# ll /dev/sd* brw-rw----. 1 root disk 8, 0 Dec 2 20:26 /dev/sda brw-rw----. 1 root disk 8, 1 Dec 2 20:26 /dev/sda1 brw-rw----. 1 root disk 8, 2 Dec 2 20:26 /dev/sda2 brw-rw----. 1 root disk 8, 16 Dec 2 20:26 /dev/sdb brw-rw----. 1 root disk 8, 17 Dec 2 20:26 /dev/sdb1 brw-rw----. 1 root disk 8, 32 Dec 2 20:26 /dev/sdc brw-rw----. 1 root disk 8, 33 Dec 2 20:26 /dev/sdc1 brw-rw----. 1 root disk 8, 48 Dec 2 20:26 /dev/sdd brw-rw----. 1 root disk 8, 49 Dec 2 20:26 /dev/sdd1 brw-rw----. 1 root disk 8, 64 Dec 2 20:26 /dev/sde brw-rw----. 1 root disk 8, 65 Dec 2 20:26 /dev/sde1
[root@rac1 opt]# 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. ACTION=="add",KERNEL=="/dev/sdb1",RUN+='/bin/raw /dev/raw/raw1 %N" ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="17",RUN+="/bin/raw /dev/raw/raw1 %M %m" ACTION=="add",KERNEL=="/dev/sdc1",RUN+='/bin/raw /dev/raw/raw2 %N" ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="33",RUN+="/bin/raw /dev/raw/raw2 %M %m" ACTION=="add",KERNEL=="/dev/sdd1",RUN+='/bin/raw /dev/raw/raw3 %N" ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="49",RUN+="/bin/raw /dev/raw/raw3 %M %m" ACTION=="add",KERNEL=="/dev/sde1",RUN+='/bin/raw /dev/raw/raw4 %N" ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="65",RUN+="/bin/raw /dev/raw/raw4 %M %m" KERNEL=="raw[1-4]",OWNER="grid",GROUP="asmadmin",MODE="660"
[root@rac1 opt]# ll /dev/raw total 0 crw-rw----. 1 grid asmadmin 162, 1 Dec 2 21:09 raw1 crw-rw----. 1 grid asmadmin 162, 2 Dec 2 21:09 raw2 crw-rw----. 1 grid asmadmin 162, 3 Dec 2 21:09 raw3 crw-rw----. 1 grid asmadmin 162, 4 Dec 2 20:26 raw4 crw-rw----. 1 root disk 162, 0 Dec 2 20:26 rawctl
一天，由于磁盘出现IO问题，导致RAC经常重启，存储修复磁盘切换了存储链路，导致映射到OS上的存储设备名发生了改变，导致UDEV绑定失败
下面修改UDEV的绑定方式，通过UUID绑定磁盘，如下
[root@rac1 ~]# for i in `cat /proc/partitions | awk '{print $4}' |grep sd | grep [a-z]$`; do echo "### $i: `scsi_id -g -u -d /dev/$i`"; done
### sda: 1ATA_VBOX_HARDDISK_VB85d0d4ba-e17b3dda
### sdb: 1ATA_VBOX_HARDDISK_VBc325912a-0addf096
### sdc: 1ATA_VBOX_HARDDISK_VB03a27735-42af5dea
### sdd: 1ATA_VBOX_HARDDISK_VB207dd3a2-a2f610c4
### sde: 1ATA_VBOX_HARDDISK_VBbc4b578d-a8e62d78
vi /etc/udev/rules.d/99-asm-oracle.rules
ACTION=="add",BUS=="scsi", KERNEL=="sd*", PROGRAM=="/sbin/scsi_id --whitelisted --replace-whitespace --device=/dev/$name", RESULT=="1ATA_VBOX_HARDDISK_VBc325912a-0addf096", RUN+="/bin/raw /dev/raw/raw1 %N"
ACTION=="add",BUS=="scsi", KERNEL=="sd*", PROGRAM=="/sbin/scsi_id --whitelisted --replace-whitespace --device=/dev/$name", RESULT=="1ATA_VBOX_HARDDISK_VB03a27735-42af5dea", RUN+="/bin/raw /dev/raw/raw2 %N"
ACTION=="add",BUS=="scsi", KERNEL=="sd*", PROGRAM=="/sbin/scsi_id --whitelisted --replace-whitespace --device=/dev/$name", RESULT=="1ATA_VBOX_HARDDISK_VB207dd3a2-a2f610c4", RUN+="/bin/raw /dev/raw/raw3 %N"
ACTION=="add",BUS=="scsi", KERNEL=="sd*", PROGRAM=="/sbin/scsi_id --whitelisted --replace-whitespace --device=/dev/$name", RESULT=="1ATA_VBOX_HARDDISK_VBbc4b578d-a8e62d78", RUN+="/bin/raw /dev/raw/raw4 %N"
KERNEL=="raw[1-4]",OWNER="grid",GROUP="asmadmin",MODE="0660"
删除 /etc/udev/rules.d/60-raw.rules 文件的绑定方式，关闭了所有节点的CRS，重新启动UDEV
[root@rac1 ~]# /u01/app/11.2.0/grid/bin/crsctl stop crs [root@rac2 ~]# /u01/app/11.2.0/grid/bin/crsctl stop crs [root@rac1 ~]# start_udev
启动CRS，发现CRS识别不到表决磁盘，crs alter报错信息如下
[root@rac1 rac1]# tail -f alertrac1.log [ohasd(5337)]CRS-2767:Resource state recovery not attempted for 'ora.diskmon' as its target state is OFFLINE 2019-12-02 21:20:40.230: [ohasd(5337)]CRS-2769:Unable to failover resource 'ora.diskmon'. 2019-12-02 21:20:42.580: [cssd(6272)]CRS-1714:Unable to discover any voting files, retrying discovery in 15 seconds; Details at (:CSSNM00070:) in /u01/app/11.2.0/grid/log/rac1/cssd/ocssd.log 2019-12-02 21:20:57.605: [cssd(6272)]CRS-1714:Unable to discover any voting files, retrying discovery in 15 seconds; Details at (:CSSNM00070:) in /u01/app/11.2.0/grid/log/rac1/cssd/ocssd.log
ocssd.log的报错信息如下：
[root@rac1 ~]# tail -f /u01/app/11.2.0/grid/log/rac1/cssd/ocssd.log 2019-12-02 21:21:27.636: [ SKGFD][411584256]Execute glob on the string /dev/raw/* 2019-12-02 21:21:27.636: [ SKGFD][411584256]running stat on disk:/dev/raw/raw1 2019-12-02 21:21:27.636: [ SKGFD][411584256]running stat on disk:/dev/raw/raw3 2019-12-02 21:21:27.636: [ SKGFD][411584256]running stat on disk:/dev/raw/raw2 2019-12-02 21:21:27.636: [ SKGFD][411584256]running stat on disk:/dev/raw/raw4 2019-12-02 21:21:27.636: [ SKGFD][411584256]running stat on disk:/dev/raw/rawctl 2019-12-02 21:21:27.636: [ SKGFD][411584256]Fetching UFS disk :/dev/raw/rawctl: 2019-12-02 21:21:27.637: [ SKGFD][411584256]Fetching UFS disk :/dev/raw/raw4: 2019-12-02 21:21:27.637: [ SKGFD][411584256]Fetching UFS disk :/dev/raw/raw2: 2019-12-02 21:21:27.637: [ SKGFD][411584256]Fetching UFS disk :/dev/raw/raw3: 2019-12-02 21:21:27.637: [ SKGFD][411584256]Fetching UFS disk :/dev/raw/raw1: 2019-12-02 21:21:27.637: [ SKGFD][411584256]OSS discovery with :: 2019-12-02 21:21:27.638: [ SKGFD][411584256]Handle 0x7f8704140a50 from lib :UFS:: for disk :/dev/raw/raw4: 2019-12-02 21:21:27.638: [ SKGFD][411584256]Handle 0x7f8704138d60 from lib :UFS:: for disk :/dev/raw/raw2: 2019-12-02 21:21:27.638: [ SKGFD][411584256]Handle 0x7f8704139590 from lib :UFS:: for disk :/dev/raw/raw3: 2019-12-02 21:21:27.638: [ SKGFD][411584256]Handle 0x7f8704141e40 from lib :UFS:: for disk :/dev/raw/raw1: 2019-12-02 21:21:27.639: [ SKGFD][411584256]Lib :UFS:: closing handle 0x7f8704140a50 for disk :/dev/raw/raw4: 2019-12-02 21:21:27.639: [ SKGFD][411584256]Lib :UFS:: closing handle 0x7f8704138d60 for disk :/dev/raw/raw2: 2019-12-02 21:21:27.639: [ SKGFD][411584256]Lib :UFS:: closing handle 0x7f8704139590 for disk :/dev/raw/raw3: 2019-12-02 21:21:27.639: [ SKGFD][411584256]Lib :UFS:: closing handle 0x7f8704141e40 for disk :/dev/raw/raw1: 2019-12-02 21:21:27.639: [ CSSD][411584256]clssnmvDiskVerify: Successful discovery of 0 disks 2019-12-02 21:21:27.639: [ CSSD][411584256]clssnmCompleteInitVFDiscovery: Completing initial voting file discovery 2019-12-02 21:21:27.639: [ CSSD][411584256]clssnmvFindInitialConfigs: No voting files found 2019-12-02 21:21:27.639: [ CSSD][411584256](:CSSNM00070:)clssnmCompleteInitVFDiscovery: Voting file not found. Retrying discovery in 15 seconds 2019-12-02 21:21:27.766: [ CSSD][414275328]clssscSelect: cookie accept request 0x7f8710083a90 2019-12-02 21:21:27.766: [ CSSD][414275328]clssscevtypSHRCON: getting client with cmproc 0x7f8710083a90 2019-12-02 21:21:27.766: [ CSSD][414275328]clssgmRegisterClient: proc(5/0x7f8710083a90), client(40/0x7f8710063d30) 2019-12-02 21:21:27.766: [ CSSD][414275328]clssgmExecuteClientRequest(): type(6) size(684) only connect and exit messages are allowed before lease acquisition proc(0x7f8710083a90) client(0x7f8710063d30) 2019-12-02 21:21:27.766: [ CSSD][414275328]clssgmDiscEndpcl: gipcDestroy 0xdcc 2019-12-02 21:21:28.521: [ CSSD][414275328]clssscSelect: cookie accept request 0x7f871006f0b0 2019-12-02 21:21:28.521: [ CSSD][414275328]clssscevtypSHRCON: getting client with cmproc 0x7f871006f0b0 2019-12-02 21:21:28.521: [ CSSD][414275328]clssgmRegisterClient: proc(3/0x7f871006f0b0), client(42/0x7f8710063d30) 2019-12-02 21:21:28.521: [ CSSD][414275328]clssgmExecuteClientRequest(): type(6) size(684) only connect and exit messages are allowed before lease acquisition proc(0x7f871006f0b0) client(0x7f8710063d30) 2019-12-02 21:21:28.521: [ CSSD][414275328]clssgmDiscEndpcl: gipcDestroy 0xde2 2019-12-02 21:21:28.767: [ CSSD][414275328]clssscSelect: cookie accept request 0x7f8710083a90 2019-12-02 21:21:28.767: [ CSSD][414275328]clssscevtypSHRCON: getting client with cmproc 0x7f8710083a90 2019-12-02 21:21:28.767: [ CSSD][414275328]clssgmRegisterClient: proc(5/0x7f8710083a90), client(41/0x7f8710096260) 2019-12-02 21:21:28.767: [ CSSD][414275328]clssgmExecuteClientRequest(): type(6) size(684) only connect and exit messages are allowed before lease acquisition proc(0x7f8710083a90) client(0x7f8710096260) 2019-12-02 21:21:28.767: [ CSSD][414275328]clssgmDiscEndpcl: gipcDestroy 0xdf8
rac1:/home/grid$ kfod asm_diskstring='/dev/raw/*' disks=all -------------------------------------------------------------------------------- Disk Size Path User Group ================================================================================ 1: 1019 Mb /dev/raw/raw1 grid asmadmin 2: 1019 Mb /dev/raw/raw2 grid asmadmin 3: 1019 Mb /dev/raw/raw3 grid asmadmin 4: 8189 Mb /dev/raw/raw4 grid asmadmin KFOD-00301: Unable to contact Cluster Synchronization Services (CSS). Return code 2 from kgxgncin. KFOD-00311: Error scanning device /dev/raw/rawctl ORA-15025: could not open disk "/dev/raw/rawctl" Linux-x86_64 Error: 13: Permission denied Additional information: 42
rac1:/home/grid$ kfed read /dev/raw/raw1
kfbh.endian: 0 ; 0x000: 0x00
kfbh.hard: 0 ; 0x001: 0x00
kfbh.type: 0 ; 0x002: KFBTYP_INVALID
kfbh.datfmt: 0 ; 0x003: 0x00
kfbh.block.blk: 0 ; 0x004: blk=0
kfbh.block.obj: 0 ; 0x008: file=0
kfbh.check: 0 ; 0x00c: 0x00000000
kfbh.fcn.base: 0 ; 0x010: 0x00000000
kfbh.fcn.wrap: 0 ; 0x014: 0x00000000
kfbh.spare1: 0 ; 0x018: 0x00000000
kfbh.spare2: 0 ; 0x01c: 0x00000000
7FCB36A16400 00000000 00000000 00000000 00000000 [................]
Repeat 26 times
7FCB36A165B0 00000000 00000000 BB43868B 01000000 [..........C.....]
7FCB36A165C0 FE830001 003F813F DDC30000 0000001F [....?.?.........]
7FCB36A165D0 00000000 00000000 00000000 00000000 [................]
Repeat 1 times
7FCB36A165F0 00000000 00000000 00000000 AA550000 [..............U.]
7FCB36A16600 00000000 00000000 00000000 00000000 [................]
Repeat 223 times
KFED-00322: Invalid content encountered during block traversal: [kfbtTraverseBlock][Invalid OSM block type][][0]
将UDEV的绑定方式从绑定设备的UUID改回原来的绑定设备名，start_udev，磁盘恢复正常，集群启动成功。
[root@rac1 opt]# 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.
ACTION=="add",KERNEL=="/dev/sdb1",RUN+='/bin/raw /dev/raw/raw1 %N"
ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="17",RUN+="/bin/raw /dev/raw/raw1 %M %m"
ACTION=="add",KERNEL=="/dev/sdc1",RUN+='/bin/raw /dev/raw/raw2 %N"
ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="33",RUN+="/bin/raw /dev/raw/raw2 %M %m"
ACTION=="add",KERNEL=="/dev/sdd1",RUN+='/bin/raw /dev/raw/raw3 %N"
ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="49",RUN+="/bin/raw /dev/raw/raw3 %M %m"
ACTION=="add",KERNEL=="/dev/sde1",RUN+='/bin/raw /dev/raw/raw4 %N"
ACTION=="add",ENV{MAJOR}=="8",ENV{MINOR}=="65",RUN+="/bin/raw /dev/raw/raw4 %M %m"
KERNEL=="raw[1-4]",OWNER="grid",GROUP="asmadmin",MODE="660"
rac1:/home/grid$ kfed read /dev/raw/raw1 kfbh.endian: 1 ; 0x000: 0x01 kfbh.hard: 130 ; 0x001: 0x82 kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD kfbh.datfmt: 1 ; 0x003: 0x01 kfbh.block.blk: 0 ; 0x004: blk=0 kfbh.block.obj: 2147483648 ; 0x008: disk=0 kfbh.check: 1914149503 ; 0x00c: 0x72179a7f kfbh.fcn.base: 0 ; 0x010: 0x00000000 kfbh.fcn.wrap: 0 ; 0x014: 0x00000000 kfbh.spare1: 0 ; 0x018: 0x00000000 kfbh.spare2: 0 ; 0x01c: 0x00000000 kfdhdb.driver.provstr: ORCLDISK ; 0x000: length=8 kfdhdb.driver.reserved[0]: 0 ; 0x008: 0x00000000 kfdhdb.driver.reserved[1]: 0 ; 0x00c: 0x00000000 kfdhdb.driver.reserved[2]: 0 ; 0x010: 0x00000000 kfdhdb.driver.reserved[3]: 0 ; 0x014: 0x00000000 kfdhdb.driver.reserved[4]: 0 ; 0x018: 0x00000000 kfdhdb.driver.reserved[5]: 0 ; 0x01c: 0x00000000 kfdhdb.compat: 186646528 ; 0x020: 0x0b200000 kfdhdb.dsknum: 0 ; 0x024: 0x0000 kfdhdb.grptyp: 2 ; 0x026: KFDGTP_NORMAL kfdhdb.hdrsts: 3 ; 0x027: KFDHDR_MEMBER kfdhdb.dskname: CRS_0000 ; 0x028: length=8 kfdhdb.grpname: CRS ; 0x048: length=3 kfdhdb.fgname: CRS_0000 ; 0x068: length=8 kfdhdb.capname: ; 0x088: length=0 kfdhdb.crestmp.hi: 33091668 ; 0x0a8: HOUR=0x14 DAYS=0x2 MNTH=0xc YEAR=0x7e3 kfdhdb.crestmp.lo: 3665632256 ; 0x0ac: USEC=0x0 MSEC=0x347 SECS=0x27 MINS=0x36 kfdhdb.mntstmp.hi: 33091668 ; 0x0b0: HOUR=0x14 DAYS=0x2 MNTH=0xc YEAR=0x7e3 kfdhdb.mntstmp.lo: 3884250112 ; 0x0b4: USEC=0x0 MSEC=0x13d SECS=0x38 MINS=0x39 kfdhdb.secsize: 512 ; 0x0b8: 0x0200 kfdhdb.blksize: 4096 ; 0x0ba: 0x1000 kfdhdb.ausize: 1048576 ; 0x0bc: 0x00100000 kfdhdb.mfact: 113792 ; 0x0c0: 0x0001bc80 kfdhdb.dsksize: 1019 ; 0x0c4: 0x000003fb kfdhdb.pmcnt: 2 ; 0x0c8: 0x00000002 kfdhdb.fstlocn: 1 ; 0x0cc: 0x00000001 kfdhdb.altlocn: 2 ; 0x0d0: 0x00000002 kfdhdb.f1b1locn: 2 ; 0x0d4: 0x00000002 kfdhdb.redomirrors[0]: 0 ; 0x0d8: 0x0000 kfdhdb.redomirrors[1]: 0 ; 0x0da: 0x0000 kfdhdb.redomirrors[2]: 0 ; 0x0dc: 0x0000 kfdhdb.redomirrors[3]: 0 ; 0x0de: 0x0000 kfdhdb.dbcompat: 168820736 ; 0x0e0: 0x0a100000 kfdhdb.grpstmp.hi: 33091668 ; 0x0e4: HOUR=0x14 DAYS=0x2 MNTH=0xc YEAR=0x7e3 kfdhdb.grpstmp.lo: 3665294336 ; 0x0e8: USEC=0x0 MSEC=0x1fd SECS=0x27 MINS=0x36 kfdhdb.vfstart: 256 ; 0x0ec: 0x00000100 kfdhdb.vfend: 288 ; 0x0f0: 0x00000120 kfdhdb.spfile: 59 ; 0x0f4: 0x0000003b kfdhdb.spfflg: 1 ; 0x0f8: 0x00000001 kfdhdb.ub4spare[0]: 0 ; 0x0fc: 0x00000000 kfdhdb.ub4spare[1]: 0 ; 0x100: 0x00000000 kfdhdb.ub4spare[2]: 0 ; 0x104: 0x00000000 kfdhdb.ub4spare[3]: 0 ; 0x108: 0x00000000 kfdhdb.ub4spare[4]: 0 ; 0x10c: 0x00000000 kfdhdb.ub4spare[5]: 0 ; 0x110: 0x00000000 kfdhdb.ub4spare[6]: 0 ; 0x114: 0x00000000 kfdhdb.ub4spare[7]: 0 ; 0x118: 0x00000000 kfdhdb.ub4spare[8]: 0 ; 0x11c: 0x00000000 kfdhdb.ub4spare[9]: 0 ; 0x120: 0x00000000 kfdhdb.ub4spare[10]: 0 ; 0x124: 0x00000000 kfdhdb.ub4spare[11]: 0 ; 0x128: 0x00000000 kfdhdb.ub4spare[12]: 0 ; 0x12c: 0x00000000 kfdhdb.ub4spare[13]: 0 ; 0x130: 0x00000000 kfdhdb.ub4spare[14]: 0 ; 0x134: 0x00000000 kfdhdb.ub4spare[15]: 0 ; 0x138: 0x00000000 kfdhdb.ub4spare[16]: 0 ; 0x13c: 0x00000000 kfdhdb.ub4spare[17]: 0 ; 0x140: 0x00000000 kfdhdb.ub4spare[18]: 0 ; 0x144: 0x00000000 kfdhdb.ub4spare[19]: 0 ; 0x148: 0x00000000 kfdhdb.ub4spare[20]: 0 ; 0x14c: 0x00000000 kfdhdb.ub4spare[21]: 0 ; 0x150: 0x00000000 kfdhdb.ub4spare[22]: 0 ; 0x154: 0x00000000 kfdhdb.ub4spare[23]: 0 ; 0x158: 0x00000000 kfdhdb.ub4spare[24]: 0 ; 0x15c: 0x00000000 kfdhdb.ub4spare[25]: 0 ; 0x160: 0x00000000 kfdhdb.ub4spare[26]: 0 ; 0x164: 0x00000000 kfdhdb.ub4spare[27]: 0 ; 0x168: 0x00000000 kfdhdb.ub4spare[28]: 0 ; 0x16c: 0x00000000 kfdhdb.ub4spare[29]: 0 ; 0x170: 0x00000000 kfdhdb.ub4spare[30]: 0 ; 0x174: 0x00000000 kfdhdb.ub4spare[31]: 0 ; 0x178: 0x00000000 kfdhdb.ub4spare[32]: 0 ; 0x17c: 0x00000000 kfdhdb.ub4spare[33]: 0 ; 0x180: 0x00000000 kfdhdb.ub4spare[34]: 0 ; 0x184: 0x00000000 kfdhdb.ub4spare[35]: 0 ; 0x188: 0x00000000 kfdhdb.ub4spare[36]: 0 ; 0x18c: 0x00000000 kfdhdb.ub4spare[37]: 0 ; 0x190: 0x00000000 kfdhdb.ub4spare[38]: 0 ; 0x194: 0x00000000 kfdhdb.ub4spare[39]: 0 ; 0x198: 0x00000000 kfdhdb.ub4spare[40]: 0 ; 0x19c: 0x00000000 kfdhdb.ub4spare[41]: 0 ; 0x1a0: 0x00000000 kfdhdb.ub4spare[42]: 0 ; 0x1a4: 0x00000000 kfdhdb.ub4spare[43]: 0 ; 0x1a8: 0x00000000 kfdhdb.ub4spare[44]: 0 ; 0x1ac: 0x00000000 kfdhdb.ub4spare[45]: 0 ; 0x1b0: 0x00000000 kfdhdb.ub4spare[46]: 0 ; 0x1b4: 0x00000000 kfdhdb.ub4spare[47]: 0 ; 0x1b8: 0x00000000 kfdhdb.ub4spare[48]: 0 ; 0x1bc: 0x00000000 kfdhdb.ub4spare[49]: 0 ; 0x1c0: 0x00000000 kfdhdb.ub4spare[50]: 0 ; 0x1c4: 0x00000000 kfdhdb.ub4spare[51]: 0 ; 0x1c8: 0x00000000 kfdhdb.ub4spare[52]: 0 ; 0x1cc: 0x00000000 kfdhdb.ub4spare[53]: 0 ; 0x1d0: 0x00000000 kfdhdb.acdb.aba.seq: 0 ; 0x1d4: 0x00000000 kfdhdb.acdb.aba.blk: 0 ; 0x1d8: 0x00000000 kfdhdb.acdb.ents: 0 ; 0x1dc: 0x0000 kfdhdb.acdb.ub2spare: 0 ; 0x1de: 0x0000
这里有个疑问，udev 更改磁盘绑定策略 （ 由之前绑定盘名 改为 绑定 uuid ）, start_udev 会写磁盘头？？
这个环境中有4块共享磁盘，raw1-3是集群的CRS磁盘，raw4还没有给集群使用
1. 下面使用dd命令，分别对udev绑定设备名和绑定UUID后的raw1进行dd磁盘前4K
rac1:/home/grid$ dd if=/dev/raw/raw1 of=/tmp/raw1.txt bs=1k count=4
udev绑定设备名的raw1前4K，能看出来有CRS磁盘组信息
udev绑定UUID的raw1前4K，能看出来磁盘头有改名，磁盘组信息消失
2. 因为 raw4 没有被RAC使用，先使用dd命令清空磁盘头，dd磁盘前4K，再执行 start_udev ，再dd磁盘前4K，进行对比
# dd if=/dev/zero of=/dev/raw/raw4 bs=1M count=30 $ dd if=/dev/raw/raw4 of=/tmp/raw4.txt bs=1k count=4
执行 start_udev 前的 raw4 的前4K，能看出来是空的
执行 start_udev 后的 raw4 的前4K
