oracle asm dd所出要的块

前一篇写了asm里dd出文件，这篇里只dd出块，主要是针对文件大的情况。

以scott模式为例：

修改前的表信息

SQL>select * from emp where mgr=7566 and empno=77887788 SCOTT     ANALYST    7566 1987/4/19     3000.00               20

1 AU计算：

SQL> selectextent_Id,block_id,blocks,file_id  2  fromdba_extents where segment_name='EMP'SQL> / EXTENT_ID  BLOCK_ID     BLOCKS    FILE_ID-------------------- ---------- ----------         0        144          8          5

SQL> selectname from v$datafile where file#=5;NAME--------------------------------------------------------------+DATA/db/datafile/users.276.899048797SQL> selectname,group_number,file_number from v$asm_alias where name like '%USERS%' andfile_number=276;NAME               GROUP_NUMBER FILE_NUMBER---------------------------------------------------------------------------------- -----------USERS.276.899048797          1        276SQL> selectdisk_kffxp,au_kffxp,xnum_kffxp from x$kffxp where group_kffxp=1 andnumber_kffxp=276;DISK_KFFXP  AU_KFFXP XNUM_KFFXP---------- ---------- ----------        1        426          0        0        289          1

这里计算一下，其block_id为144,块大小为8KB,那么其位置为144*8/1024=1.125M,加上块头8*8/1024=0.0625M,一共不超过4M;应当在第一个AU上（AU大小为4M），第二块盘的第426个AU上，取第二个盘路径：

SQL> selectdisk_number,path from v$asm_disk where disk_number=1;DISK_NUMBERPATH-------------------------------------------------------------------------------------------          1 /dev/raw/raw2

取出该表的最大和最小data_object_id,然后dd.

SQL>  select dbms_rowid.rowid_relative_fno(rowid)rel_fno, max(dbms_rowid.rowid_block_number(rowid))max_block, min(dbms_rowid.rowid_block_number(rowid))min_block from emp group by dbms_rowid.rowid_relative_fno(rowid);    REL_FNO MAX_BLOCK  MIN_BLOCK-------------------- ----------         5        149       149[oracle@mysql-1]$ddif=/dev/raw/raw2 bs=1024 count=8 skip=1746088 of=emp.dd

说明一下：skip=426*4*1024+149*8

检查一下：

[oracle@mysql-1~]$ strings emp.ddMILLERCLERKFORDANALYSTJAMESCLERKADAMSCLERKTURNERSALESMANKING    PRESIDENTSCOTTANALYSTSMITHCLERK

从上可以看出，是emp的内容。

2 bbed修改内容

11g里首先要安装bbed,安装过程记录一下：

copy oracle 10g的sbbdpt.o,ssbbded.o到$ORACLE_HOME/rdbms/lib下copybbedus.msb 到$ORACLE_HOME/mesg下cd$ORACLE_HOME/rdbms/libmake -fins_rdbms.mk $ORACLE_HOME/rdbms/lib/bbedcp bbed$ORACLE_HOME/bin

[oracle@mysql-1~]$ bbedBBED> set filename'/home/oracle/emp.dd';       FILENAME        /home/oracle/emp.dd

#用bbed校验下块。BBED> verifyDBVERIFY - Verification startingFILE = /home/oracle/emp.ddBLOCK = 0Block 0 is corruptCorrupt block relative dba: 0x01400000(file 0, block 0)Bad header found during verificationData in bad block: type: 6 format: 2 rdba: 0x01400095 lastchange scn: 0x0000.0004dec0 seq: 0x1 flg: 0x06 spare1: 0x0 spare2: 0x0 spare3: 0x0 consistency value in tail: 0x00000000 check value in block header: 0x89af computed block checksum: 0xd6b  DBVERIFY - Verification completeTotal Blocks Examined         : 1Total Blocks Processed (Data) : 0Total Blocks Failing   (Data) : 0Total Blocks Processed (Index): 0Total Blocks Failing   (Index): 0Total Blocks Empty            : 0Total Blocks Marked Corrupt   : 1Total Blocks Influx           : 0Message 531 not found;  product=RDBMS; facility=BBED

用bbed查看dd出文件内容

BBED> set blocksize 8192        BLOCKSIZE       8192BBED> p kdbrBBED> find /c SCOTT File: /home/oracle/emp.dd (0) Block: 1                Offsets: 7864 to 8191           Dba:0x00000000------------------------------------------------------------------------ 53434f54 5407414e 414c5953 5403c24c 430777bb04130101 0102c21f ff02c115BBED> dump /v File: /home/oracle/emp.dd (0) Block: 1      Offsets: 7864 to 8191  Dba:0x00000000------------------------------------------------------- 53434f54 5407414e 414c5953 5403c24c lSCOTT.ANALYST..L 430777bb 04130101 0102c21f ff02c115 lC.w............. 2c010803 c24e5305 434c4152 4b074d41 l,....NS.CLARK.MA 4e414745 5203c24f 280777b5 06090101 lNAGER..O(.w..... 0103c219 33ff02c1 0b2c0108 03c24d63 l....3....,....Mc

用bbed修改：

set mode editset blocksize 8192find /c SCOTTm /c SNOWHBBED> dump /v File: /home/oracle/emp.dd (0) Block: 1      Offsets: 7864 to 8191 Dba:0x00000000------------------------------------------------------- 534e4f57 4807414e 414c5953 5403c24c lSNOWH.ANALYST..LBBED> sumCheck value for File 0, Block 1:current = 0x89af, required = 0x87b3 BBED> sum applyCheck value for File 0, Block 1:current = 0x87b3, required = 0x87b3

关库，导入修改后数据：

[oracle@mysql-1~]$ srvctl stop database -d db[oracle@mysql-1~]$dd of=/dev/raw/raw2 bs=1024 count=8 seek=1746088 if=emp.dd8+0 records in8+0 records out8192 bytes (8.2 kB) copied, 0.00208818 s,3.9 MB/s

查询表信息：

[oracle@mysql-1~]$ srvctl start database -d db

SQL> select* from emp where mgr=7566 and empno=7788 2  ;EMPNOENAME      JOB         MGR HIREDATE          SAL      COMM DEPTNO--------------- --------- ----- ----------- --------- --------- ------ 7788 SNOWH     ANALYST    7566 1987/4/19     3000.00               20

OVER