Oracle如何在ASM中定位文件的分布

核心提示：kfffde[0].xptr.chk: 128 ; 0x4a7: 0x80kfffde[1].xptr.au: 4294967295 ; 0x4a8: 0xffffffffkfffde[1].xptr.disk: 65535 ; 0x4ac:

kfffde[0].xptr.chk: 128 ; 0x4a7: 0x80
kfffde[1].xptr.au: 4294967295 ; 0x4a8: 0xffffffff
kfffde[1].xptr.disk: 65535 ; 0x4ac: 0xffff
kfffde[1].xptr.flags: 0 ; 0x4ae: L=0 E=0 D=0 S=0
kfffde[1].xptr.chk: 42 ; 0x4af: 0x2a
我们可以看到只有：
kfffde[0].xptr.au: 936 ; 0x4a0: 0x000003a8
而下一个：
kfffde[1].xptr.au: 4294967295 ; 0x4a8: 0xffffffff
是还没分配数据的，这也印证了我们的配置，external的dg，没有冗余，因此每个au只有primary extents，即1个au，接下来我们通过os的dd命令将该文件copy出来，我们可以直接将spfile dd到文本文件：
+ASM> select group_kfdat,number_kfdat,aunum_kfdat from x$kfdat where fnum_kfdat=265;

GROUP_KFDAT NUMBER_KFDAT AUNUM_KFDAT
----------- ------------ -----------
1 1 936
从上面信息我们得到该文件业绩spfile的在磁盘的物理位置：
[grid@gtser2 ~]$ dd if=/dev/asm11g-g skip=936 of=/tmp/dbspfile bs=1024k count=1
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.00721405 seconds, 145 MB/s
[grid@gtser2 ~]$ cat /tmp/dbspfile
C"

(%3tQ0
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yKGT11G.__db_cache_size=301989888
GT11G.__java_pool_size=4194304
GT11G.__large_pool_size=4194304
GT11G.__oracle_base='/u02/app/oracle'#ORACLE_BASE set from environment
GT11G.__pga_aggregate_target=159383552
GT11G.__sga_target=469762048
GT11G.__shared_io_pool_size=0
GT11G.__shared_pool_size=146800640
GT11G.__streams_pool_size=0
*.audit_file_dest='/u02/app/oracle/admin/GT11G/adump'
*.audit_trail='db'
*.compatible='11.2.0.0.0'
*.control_files='+DATA01/gt11g/controlfile/current.256.8104718
CC"
y/79','+FRA/gt11g/controlfile/current.256.810471883'
*.db_block_size=8192
*.db_create_file_dest='+DATA01'
*.db_domain=''
*.db_name='GT11G'
*.db_recovery_file_dest='+FRA'
*.db_recovery_file_dest_size=5218762752
*.diagnostic_dest='/u02/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=GT11GXDB)'
*.log_archive_format='%t_%s_%r.dbf'
*.nls_language='SIMPLIFIED CHINESE'
*.nls_territory='CHINA'
*.open_cursors=300
*.pga_aggregate_target=156237824
*.processes=150
*.remote_login_passwordfile='E
CC"
YcXCLUSIVE'
*.sga_target=469762048
*.undo_tablespace='UNDOTBS1'

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C[grid@gtser2 ~]$

0. 控制文件
sys@GT11G> show parameter control_files

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
control_files string +DATA01/gt11g/controlfile/curr
ent.256.810471879, +FRA/gt11g/
controlfile/current.256.810471
883
+ASM> select XNUM_KFFXP , PXN_KFFXP , LXN_KFFXP , DISK_KFFXP , AU_KFFXP,size_kffxp
2 from X$KFFXP
3 where GROUP_KFFXP=1 and NUMBER_KFFXP=256 and XNUM_KFFXP<>2147483648
4 order by 1,2;