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标题：dd破坏asm磁盘头恢复
作者：惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]
有朋友对asm disk的磁盘头dd了2048byte的数据
通过分析,gi软件版本,确认是11.2.0.4
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production With the Real Application Clusters and Automatic Storage Management options. ORACLE_HOME = /u01/app/11.2.0/grid System name: Linux Node name: rac1 Release: 4.1.12-37.4.1.el6uek.x86_64 Version: #2 SMP Tue May 17 07:23:38 PDT 2016 Machine: x86_64
从10.2.0.5之后版本,在第二个au的倒数第二个block上面,有asm disk header备份（每个block大小为4k）,分析au大小(通过分析正常的asm disk快速找到au 大小【使用dd备份的正常的磁盘头查看】)
H:\TEMP\tmp\asmbak>kfed read sdcp.dd |grep ausize kfdhdb.ausize: 16777216 ; 0x0bc: 0x01000000
找到被破坏的asm disk的备份磁盘头信息
H:\TEMP\tmp\asmbak>kfed read sdc.dd blkn=4094 aun=1 aus=16777216|more kfbh.endian: 1 ; 0x000: 0x01 kfbh.hard: 130 ; 0x001: 0x82 kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD kfbh.datfmt: 1 ; 0x003: 0x01 kfbh.block.blk: 4094 ; 0x004: blk=4094 kfbh.block.obj: 2147483648 ; 0x008: disk=0 kfbh.check: 229348702 ; 0x00c: 0x0dab955e kfbh.fcn.base: 11727032 ; 0x010: 0x00b2f0b8 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: 1 ; 0x026: KFDGTP_EXTERNAL kfdhdb.hdrsts: 3 ; 0x027: KFDHDR_MEMBER kfdhdb.dskname: DATA_0000 ; 0x028: length=9 kfdhdb.grpname: DATA ; 0x048: length=4 kfdhdb.fgname: DATA_0000 ; 0x068: length=9 kfdhdb.capname: ; 0x088: length=0 kfdhdb.crestmp.hi: 33123276 ; 0x0a8: HOUR=0xc DAYS=0x1e MNTH=0xa YEAR=0x7e5 kfdhdb.crestmp.lo: 2259134464 ; 0x0ac: USEC=0x0 MSEC=0x1ea SECS=0x2a MINS=0x21 kfdhdb.mntstmp.hi: 33162836 ; 0x0b0: HOUR=0x14 DAYS=0x12 MNTH=0x1 YEAR=0x7e8 kfdhdb.mntstmp.lo: 3600987136 ; 0x0b4: USEC=0x0 MSEC=0xad SECS=0x2a MINS=0x35 kfdhdb.secsize: 512 ; 0x0b8: 0x0200 kfdhdb.blksize: 4096 ; 0x0ba: 0x1000 kfdhdb.ausize: 16777216 ; 0x0bc: 0x01000000 kfdhdb.mfact: 454272 ; 0x0c0: 0x0006ee80 kfdhdb.dsksize: 65536 ; 0x0c4: 0x00010000 kfdhdb.pmcnt: 2 ; 0x0c8: 0x00000002 kfdhdb.fstlocn: 1 ; 0x0cc: 0x00000001 kfdhdb.altlocn: 2 ; 0x0d0: 0x00000002 kfdhdb.f1b1locn: 0 ; 0x0d4: 0x00000000 kfdhdb.redomirrors[0]: 0 ; 0x0d8: 0x0000 kfdhdb.redomirrors[1]: 0 ; 0x0da: 0x0000 kfdhdb.redomirrors[2]: 0 ; 0x0dc: 0x0000 …………
确认被损坏的磁盘只有磁盘头信息损坏(即确认第二个block是否是好的)
H:\TEMP\tmp\asmbak>kfed read sdc.dd blkn=0 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 0065D8400 00000000 00000000 00000000 00000000 [................] Repeat 255 times KFED-00322: Invalid content encountered during block traversal: [kfbtTraverseBlock][Invalid OSM block type][][0] H:\TEMP\tmp\asmbak>kfed read sdc.dd blkn=1|more kfbh.endian: 1 ; 0x000: 0x01 kfbh.hard: 130 ; 0x001: 0x82 kfbh.type: 2 ; 0x002: KFBTYP_FREESPC kfbh.datfmt: 2 ; 0x003: 0x02 kfbh.block.blk: 1 ; 0x004: blk=1 kfbh.block.obj: 2147483648 ; 0x008: disk=0 kfbh.check: 2781697777 ; 0x00c: 0xa5cd56f1 kfbh.fcn.base: 39359331 ; 0x010: 0x02589363 kfbh.fcn.wrap: 0 ; 0x014: 0x00000000 kfbh.spare1: 0 ; 0x018: 0x00000000 kfbh.spare2: 0 ; 0x01c: 0x00000000 kfdfsb.aunum: 0 ; 0x000: 0x00000000 kfdfsb.max: 1014 ; 0x004: 0x03f6 kfdfsb.cnt: 147 ; 0x006: 0x0093 kfdfsb.bound: 0 ; 0x008: 0x0000 kfdfsb.flag: 1 ; 0x00a: B=1 kfdfsb.ub1spare: 0 ; 0x00b: 0x00 kfdfsb.spare[0]: 0 ; 0x00c: 0x00000000 kfdfsb.spare[1]: 0 ; 0x010: 0x00000000 kfdfsb.spare[2]: 0 ; 0x014: 0x00000000 kfdfse[0].fse: 0 ; 0x018: FREE=0x0 FRAG=0x0 …………
基于上述分析,直接使用备份的asm disk header信息进行merge或者repair修复之后,asm 磁盘头状态恢复正常
这个客户运气比较好,库非常大,只是破坏了2k的数据,如果超过4k可能就是比较麻烦的事故了,再次提醒对asm磁盘的dd操作一定要小心谨慎.如果不慎破坏asm磁盘过多,参考以前类似文档:
asm磁盘dd破坏恢复