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标题:asm备份元数据之md_backup和md_restore
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.]
在11g的asm中增加了md_backup和md_restore命令,用来备份和还原asm的元数据信息
当前磁盘组相关信息
SQL> select PATH,b.NAME from v$asm_disk a,v$asm_diskgroup b where a.GROUP_NUMBER=b.GROUP_NUMBER; PATH NAME ---------------------------------------- ---------- /dev/oracleasm/disks/VOL2 DATA /dev/oracleasm/disks/VOL1 DATA /dev/oracleasm/disks/VOL4 XIFENFEI /dev/oracleasm/disks/VOL3 XIFENFEI
md_backup操作
--备份所有mount磁盘组 ASMCMD> md_backup /tmp/xifenfei.md Disk group metadata to be backed up: DATA Disk group metadata to be backed up: XIFENFEI Current alias directory path: XFF/ARCHIVELOG Current alias directory path: XFF/ARCHIVELOG/2012_04_30 Current alias directory path: XFF/ONLINELOG Current alias directory path: rac-cluster/OCRFILE Current alias directory path: XFF/ARCHIVELOG/2012_05_01 Current alias directory path: XFF/CONTROLFILE Current alias directory path: XFF/ARCHIVELOG/2012_04_13 Current alias directory path: rac-cluster/ASMPARAMETERFILE Current alias directory path: rac-cluster Current alias directory path: XFF Current alias directory path: XFF/ARCHIVELOG/2012_03_03 Current alias directory path: XFF/PARAMETERFILE Current alias directory path: XFF/DATAFILE Current alias directory path: ASM/DATAFILE Current alias directory path: XFF/CONTROLFILE Current alias directory path: XFF Current alias directory path: XFF/ONLINELOG Current alias directory path: XFF/TEMPFILE Current alias directory path: ASM --备份指定磁盘组 ASMCMD> md_backup /tmp/xifenfei_data.md -G DATA Disk group metadata to be backed up: DATA Current alias directory path: XFF/ARCHIVELOG/2012_03_03 Current alias directory path: XFF/CONTROLFILE Current alias directory path: XFF/ARCHIVELOG/2012_05_01 Current alias directory path: XFF/ARCHIVELOG Current alias directory path: rac-cluster/OCRFILE Current alias directory path: XFF/ARCHIVELOG/2012_05_24 Current alias directory path: XFF/ONLINELOG Current alias directory path: XFF/ARCHIVELOG/2012_04_30 Current alias directory path: rac-cluster/ASMPARAMETERFILE Current alias directory path: rac-cluster Current alias directory path: XFF Current alias directory path: XFF/ARCHIVELOG/2012_04_13
md_restore操作
--生产sql文件(未执行) ASMCMD> md_restore -S /tmp/get_dg_sql -G data /tmp/xifenfei_data.md Current Diskgroup metadata being restored: DATA 破坏XIFENFEI磁盘组中的其中一个asm disk(/dev/oracleasm/disks/VOL3) [root@rac1 tmp]# dd if=/dev/zero of=/dev/sdb1 bs=4096 count=1 1+0 records in 1+0 records out 4096 bytes (4.1 kB) copied, 4.8629e-05 seconds, 84.2 MB/s --尝试还原磁盘组(操作单位是磁盘组) ASMCMD> md_restore /tmp/xifenfei.md --silent -G xifenfei Current Diskgroup metadata being restored: XIFENFEI ASMCMD-9352: CREATE DISKGROUP failed ORA-15018: diskgroup cannot be created ORA-15033: disk /dev/oracleasm/disks/VOL4 belongs to diskgroup "XIFENFEI" (DBD ERROR: OCIStmtExecute) --如果一个磁盘组中某个asm disk 出了问题,这种方法不能生效,甚至需要先dd 处理掉所有该磁盘组中的asm disk
总结说明
md_backup和md_restore是磁盘组级别的备份和还原,如果一个磁盘组的某个asm disk出现问题,使用这对命令解决起来还是很麻烦,甚至根本不可行(因为代价太大:要删除该磁盘组其他asm disk header,然后要重新还原所有数据文件),这样的情景下dd或者kfed的备份还是非常有必要,ASM DISK HEADER 备份与恢复.如果是一个磁盘组都损坏,需要还原磁盘组,这个时候这个命令非常的完美(至少比起dd和kfed方便很多).md_backup/md_restore和dd与kfed是互补的命令,而不是md_backup/md_restore出现使得dd和kfed在asm元数据的备份恢复上就没有用武之地.
data磁盘组生成sql语句信息
md_backup生成data磁盘组备份元数据信息
md_backup和md_restore命令说明