Linux mistakenly deletes Oracle data file Recovery __ios

This article I have, the right to record inquiries, the original to the current torch Oracle Lunar goddess

[Oracle@lunar ~]$ sqlplus/as sysdba sql*plus:release 11.2.0.3.0 Production on Fri Mar 23:46:35 2013 Copyrigh   T (c) 1982, Oracle.     All rights reserved. Connected to:oracle Database 11g Enterprise Edition release 11.2.0.3.0-64bit Production with the partitioning, Ola   P, Data Mining and real application testing options sql> select Tablespace_name from Dba_tablespaces; Tablespace_name------------------------------------------------------------SYSTEM sysaux UNDOTBS1 TEM P USERS EZIO 6 rows selected.

To create a test table space

sql> Create tablespace lunar_test datafile '/test/lunar_test01.dbf ' size 10M;   Tablespace created.   sql> alter user lunar default tablespace lunar_test; User altered.

CREATE TABLE Insert Data

Sql> Conn Lunar/lunar Connected.   Sql> CREATE TABLE test_table (name VARCHAR2 ()) tablespace lunar_test;   Table created.   sql> INSERT into test_table values (' Love your Forever, my baby, Happy childrens day! ');   1 row created.   Sql> commit;   Commit complete.   Sql> sql> SELECT * from test_table; NAME--------------------------------------------------------------------------------Love your Forever, my baby, Happy Childrens Day!

Delete DataFile

sql>!rm-rf/test/lunar_test01.dbf sql>!ls-lrt/test/lunar_test01.dbf ls:/test/lunar_test01.dbf:no such fil E or directory sql>

The data is still there, because it's read from the buffer cache

Sql> Conn Lunar/lunar Connected.   Sql> select * from test_table; NAME--------------------------------------------------------------------------------Love your Forever, my baby, Happy Childrens Day!

Execute Flush Buffer Cache

Sql> conn/as sysdba Connected.   Sql> alter system flush Buffer_cache; System altered.

Can see, query again, error file status is wrong (can't find it)

Sql> Conn Lunar/lunar Connected. Sql> select * from test_table;  SELECT * FROM Test_table * ERROR at line 1:ora-01116:error in opening database file 6 Ora-01110:data file 6: '/TEST/LUNAR_TEST01.DBF ' ora-27041:unable to open file linux-x86_64 error:2: No such file or directory Additional Information:3

Check the SPID of the DBWR process

sql>!ps-ef|grep dBW Oracle 2757 1 0 12:29? 00:00:14 ora_dbw0_bb Oracle 8912 8872 0 23:50 pts/3 00:00:00/bin/bash-c ps-ef|grep dbw Oracle 8914 8912 0 23:50 PTS/3 00:00:00 grep DBW

Find the handle to DBWR

sql>!/usr/sbin/lsof-p 2757 command  pid    user    FD   TYPE DEVICE& nbsp;   size/off     node  NAME oracle  2757 oracle  cwd     dir  253,0       4096 6947181/u01/app/oracle/product/11.2.0.3/dbhome_1/ DBS oracle  2757 oracle  rtd    dir  253,0       4096        2/oracle  2757 oracle  txt    reg  253,0  232399473 1179781/u01/app/oracle/product/11.2.0.3/dbhome_1/bin/oracle oracle  2757 oracle  DEL     reg    0,4            1933317/ SYSV00000000 oracle  2757 oracle  del    reg            1966086/sysv00000000 oracle  2757oracle  del    reg    0,4             1998855/sysv2b7268c4 oracle  2757 oracle  mem    reg  253,0      144776 2293762/lib64/ld-2.5.so oracle  2757 oracle  mem    REG  253,0        5328 4822547/usr/lib64/libaio.so.1.0.1 oracle  2757 oracle  mem     reg  253,0    1722328 2293764/lib64/libc-2.5.so oracle  2757 oracle  mem& nbsp;   reg  253,0      23360 2293771/lib64/libdl-2.5.so oracle  2757 oracle  mem    reg  253,0     615136 2293809/lib64/libm-2.5.so Oracle   2757 oracle  mem    reg  253,0     145872 2293775/lib64/ libpthread-2.5.so oracle  2757 oracle  mem    reg  253,0      53448 2293781/lib64/librt-2.5.so oracle  2757 oracle    reg  253,0     114352 2293986/lib64/libnsl-2.5.so oracle  2757 oracle  mem& nbsp;   reg  253,0      58949 6955646/u01/app/oracle/product/11.2.0.3/ dbhome_1/lib/libnque11.so oracle  2757 oracle  262uw  reg  253,0   87040000 4784725/u01/ APP/ORACLE/ORADATA/BB/TEMP01.DBF oracle  2757 oracle  263uw  reg  253,0   10493952 1639050/TEST/LUNAR_TEST01.DBF (deleted)    can see that the file is identified as delete

Enter the file descriptor number directory of the DBWR process

sql>!ls-ltar/proc/2757/fd/total 0 dr-xr-xr-x 7 Oracle oinstall  0 Mar 15 12:29. DR-X------2 Oracle oinstall  0 Mar 15 12:29. LR-X------1 Oracle Oinstall 1 23:30 9->/dev/null lr-x------Oracle Oinstall Mar 23:30 8->/dev /null lrwx------1 Oracle Oinstall 23:30 7->/u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat lr-x- -----1 Oracle Oinstall 23:30 6->/dev/null lr-x------1 Oracle Oinstall Mar 23:30 5->/dev/null LR-X------1 Oracle Oinstall 1 23:30 4->/dev/null lr-x------Oracle Oinstall Mar 23:30 3->/dev /null lrwx------1 Oracle oinstall Mar 23:30 263->/test/lunar_test01.dbf (deleted)    the FD number of the process that can see DBWR LRWX------1 Oracle oinstall 23:30 262->/u01/app/oracle/oradata/bb/temp01.dbf lrwx------1 Oracle Oinsta LL-23:30 261->/u01/app/oracle/oradata/bb/ezio01.dbf lrwx------1 Oracle Oinstall-Mar 23:30T /U01/APP/ORACLE/ORADATA/BB/USERS01.DBF lrwx------1 Oracle oinstall 23:30 259->/u01/app/oracle/oradata/bb/ UNDOTBS01.DBF lrwx------1 Oracle Oinstall (23:30) 258->/u01/app/oracle/oradata/bb/sysaux01.dbf lrwx------ 1 Oracle oinstall 23:30 257->/u01/app/oracle/oradata/bb/system01.dbf lrwx------1 Oracle Oinstall 1 Mar 5 23:30 256->/u01/app/oracle/oradata/bb/control01.ctl l-wx------1 Oracle Oinstall 23:30 2->/dev/null LR-X------1 Oracle oinstall 23:30->/U01/APP/ORACLE/PRODUCT/11.2.0.3/DBHOME_1/RDBMS/MESG/ORAUS.MSB LRW X------1 Oracle Oinstall 23:30->/U01/APP/ORACLE/PRODUCT/11.2.0.3/DBHOME_1/DBS/LKBB lrwx------1 Oracl E oinstall 23:30->/u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat lr-x------1 Oracle Oinstall 23:30->/dev/zero lr-x------1 Oracle oinstall 23:30->/proc/2757/fd