本篇内容主要讲解“Oracle中amdu_extract命令有什么作用”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“Oracle中amdu_extract命令有什么作用”吧!
amdu_extract命令用来从磁盘组中抽取文件，其语法如下:
ASMCMD [+DATA/cs/DATAFILE] > help amdu_extract
amdu_extract
Calls AMDU to extract from
Synopsis
amdu_extract
Description
The options for amdu_extract command are described below:
disk group - Name of the disk group containing the file to be extracted.
file - Name of the file to be extracted. Can be specified as either an absolute or a relative path.
diskstring - Specifies the value for the discovery diskstring.
Examples
The following example uses amdu_extract to extract the parameter file from the '+datafile'
disk group.
ASMCMD [+] > amdu_extract datafile +datafile/parameterfile/spfile.ora /devices/disk*其中diskgroup为被抽取文件所在的磁盘组名字，file_name，被抽取文件的Oracle ASM别名，disk_string为Oracle ASM发现磁盘字符串。而且amdu_extract实际是调用的AMDU工具来抽取文件
查询数据库cs的所有数据文件，这里我们要抽取的文件名是JY.331.976296525
ASMCMD [+DATA/cs/DATAFILE] > ls -lrt
WARNING:option 'r' is deprecated for 'ls'
please use 'reverse'
Type Redund Striped Time Sys Name
DATAFILE UNPROT COARSE MAR 12 18:00:00 Y SYSAUX.259.970598293
DATAFILE UNPROT COARSE MAR 12 18:00:00 Y SYSTEM.258.970598233
DATAFILE UNPROT COARSE MAR 12 18:00:00 Y UNDOTBS1.260.970598319
DATAFILE UNPROT COARSE MAR 12 18:00:00 Y USERS.261.970598319
DATAFILE UNPROT COARSE AUG 16 11:00:00 Y JY.331.976296525
DATAFILE UNPROT COARSE AUG 16 11:00:00 Y SYSAUX.273.970601881
DATAFILE UNPROT COARSE AUG 16 11:00:00 Y SYSTEM.272.970601831
DATAFILE UNPROT COARSE AUG 16 11:00:00 Y TEST.326.976211663
DATAFILE UNPROT COARSE AUG 16 11:00:00 Y UNDOTBS1.274.970601905
DATAFILE UNPROT COARSE AUG 16 11:00:00 Y UNDOTBS2.284.970602381
DATAFILE UNPROT COARSE AUG 16 11:00:00 Y USERS.275.970601909
SQL> select name,file_number from v$asm_alias where file_number<>4294967295 and (name like '%jy%' or name like '%JY%');
NAME FILE_NUMBER
-------------------------------------------------------------------------------------------------------------------------------------------- -----------
JY.331.976296525 331
ASMCMD [+DATA/cs/DATAFILE] > amdu_extract DATA +DATA/cs/DATAFILE/JY.331.976296525 /dev/asm*
ASMCMD-8024: file number could not be determined for alias name '+DATA/cs/DATAFILE/JY.331.976296525'
< ?pre>
可以看到提示信息说通过文件别名不能判断文件号，实际上+DATA/cs/DATAFILE/JY.331.976296525是Oracle在ASM中创建的数据文件名，并不是别名。如是我们来手动为+DATA/cs/DATAFILE/JY.331.976296525增加别名jy01.dbfSQL> alter diskgroup data add alias '+DATA/cs/DATAFILE/jy01.dbf' for '+DATA/cs/DATAFILE/JY.331.976296525';
Diskgroup altered.
SQL> select name,file_number from v$asm_alias where file_number<>4294967295 and (name like '%jy%' or name like '%JY%');
NAME FILE_NUMBER
-------------------------------------------------------------------------------------------------------------------------------------------- -----------
JY.331.976296525 331
jy01.dbf 331
ASMCMD [+DATA/cs/DATAFILE] > amdu_extract DATA +DATA/cs/DATAFILE/jy01.dbf /dev/asm*
amdu_2018_08_16_19_17_42/[grid@cs1 ~]$ ls -lrt
drwxr-xr-x 2 grid oinstall 40 Aug 16 19:17 amdu_2018_08_16_19_17_42
[grid@cs1 ~]$ cd amdu_2018_08_16_19_17_42
[grid@cs1 amdu_2018_08_16_19_17_42]$ ls -lrt
total 102416
-rw-r--r-- 1 grid oinstall 8103 Aug 16 19:17 report.txt
-rw-r--r-- 1 grid oinstall 104865792 Aug 16 19:17 DATA_331.f使用amdu工具来抽取数据文件是指定Oracle ASM发现磁盘字符串和磁盘组.数据文件序号
[grid@cs2 ~]$ amdu -diskstring '/dev/asm*' -extract 'DATA.331'
amdu_2018_08_16_19_20_59/
AMDU-00204: Disk N0004 is in currently mounted diskgroup DATA.
AMDU-00201: Disk N0004: '/dev/asmdisk04'
[grid@cs2 ~]$ cd amdu_2018_08_16_19_20_59/
[grid@cs2 amdu_2018_08_16_19_20_59]$ ls -lrt
total 102420
-rw-r--r-- 1 grid oinstall 8291 Aug 16 19:21 report.txt
-rw-r--r-- 1 grid oinstall 104865792 Aug 16 19:21 DATA_331.f可以看到使用amdu与asmcmd的amdu_extract所抽取的同一个文件大小都是104865792。
到此，相信大家对“Oracle中amdu_extract命令有什么作用”有了更深的了解，不妨来实际操作一番吧！这里是亿速云网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！
