linux 误删除文件恢复

linux 误删除文件恢复

from:http://www.lunar2013.com/2013/06/linux-%e8%af%af%e5%88%a0%e9%99%a4%e6%96%87%e4%bb%b6%e6%81%a2%e5%a4%8d.html#comment-13 

 

发表于 2013 年 6 月 3 日 由 admin

[oracle@lunar ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Fri Mar 15 23:46:35 2013

Copyright (c) 1982, 2011, Oracle.  All rights reserved.


Connected to :
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> select tablespace_name from dba_tablespaces;

TABLESPACE_NAME
------------------------------------------------------------
SYSTEM
SYSAUX
UNDOTBS1
TEMP
USERS
EZIO

6 rows selected.

创建测试表空间

SQL> create tablespace lunar_test datafile '/test/lunar_test01.dbf' size 10M;

Tablespace created.

SQL> alter user lunar default tablespace lunar_test;

User altered.

创建表插入数据

SQL> conn lunar/lunar
Connected.
SQL> create table test_table ( name varchar2(300)) tablespace lunar_test;

Table created.

SQL> insert into test_table values ( 'Love you forever, my baby, Happy Childrens Day!' );

1 row created.

SQL> commit ;

Commit complete.

SQL>
SQL> select * from test_table;

NAME
--------------------------------------------------------------------------------
Love you forever, my baby, Happy Childrens Day !

删除datafile

SQL> !rm -rf /test/lunar_test01.dbf

SQL> !ls -lrt /test/lunar_test01.dbf
ls: /test/lunar_test01.dbf: No such file or directory

SQL>

数据还在，因为从buffer cache中读到的

SQL> conn lunar/lunar
Connected.
SQL> select * from test_table;

NAME
--------------------------------------------------------------------------------
Love you forever, my baby, Happy Childrens Day !

执行flush buffer cache

SQL> conn / as sysdba
Connected.
SQL> alter system flush buffer_cache;

System altered.

可以看见，再次查询，报错文件状态不对了（找不到了）

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

检查dbwr进程的spid

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

找到dbwr的句柄

SQL> !/usr/sbin/lsof -p 2757
COMMAND  PID   USER   FD   TYPE DEVICE   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    0,4            1966086 /SYSV00000000
oracle  2757 oracle  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    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  mem    REG  253,0     114352 2293986 /lib64/libnsl-2.5.so
oracle  2757 oracle  mem    REG  253,0      58949 6955646 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libnque11.so
oracle  2757 oracle  mem    CHR    1,5               4302 /dev/zero
oracle  2757 oracle  mem    REG  253,0       1544 6951342 /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat
oracle  2757 oracle  mem    REG  253,0      53880 2293787 /lib64/libnss_files-2.5.so
oracle  2757 oracle  mem    REG  253,0      22368 4831836 /usr/lib64/libnuma.so.1
oracle  2757 oracle  mem    REG  253,0     153574 6976596 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libocrutl11.so
oracle  2757 oracle  mem    REG  253,0    3319072 6976595 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libocrb11.so
oracle  2757 oracle  mem    REG  253,0    1590995 6976594 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libocr11.so
oracle  2757 oracle  mem    REG  253,0      12755 6953392 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libskgxn2.so
oracle  2757 oracle  mem    REG  253,0   17319952 6976562 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libhasgen11.so
oracle  2757 oracle  mem    REG  253,0     161764 6953093 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libdbcfg11.so
oracle  2757 oracle  mem    REG  253,0     228765 6976564 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libclsra11.so
oracle  2757 oracle  mem    REG  253,0    7955322 6976828 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libnnz11.so
oracle  2757 oracle  mem    REG  253,0    1010297 4456454 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libskgxp11.so
oracle  2757 oracle  mem    REG  253,0     589359 6977008 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libcell11.so
oracle  2757 oracle  mem    REG  253,0      12259 6950100 /u01/app/oracle/product/11.2.0.3/dbhome_1/lib/libodmd11.so
oracle  2757 oracle    0r   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    1w   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    2w   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    3r   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    4r   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    5r   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    6r   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    7u   REG  253,0       1544 6951342 /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat
oracle  2757 oracle    8r   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle    9r   CHR    1,3        0t0    4300 /dev/ null
oracle  2757 oracle   10r   CHR    1,5        0t0    4302 /dev/zero
oracle  2757 oracle   11r   CHR    1,5        0t0    4302 /dev/zero
oracle  2757 oracle   12u   REG  253,0       1544 6951342 /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat
oracle  2757 oracle   13r   REG  253,0    1101312 6962758 /u01/app/oracle/product/11.2.0.3/dbhome_1/rdbms/mesg/oraus.msb
oracle  2757 oracle   14r   DIR    0,3          0   10741 /proc/2757/fd
oracle  2757 oracle   15r   CHR    1,5        0t0    4302 /dev/zero
oracle  2757 oracle   16u   REG  253,0       1544 6951342 /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat
oracle  2757 oracle   17uR  REG  253,0         24 6951341 /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/lkBB
oracle  2757 oracle   18r   REG  253,0    1101312 6962758 /u01/app/oracle/product/11.2.0.3/dbhome_1/rdbms/mesg/oraus.msb
oracle  2757 oracle   19u  IPv6  42951        0t0     UDP *:29281
oracle  2757 oracle  256u   REG  253,0   10043392 4784156 /u01/app/oracle/oradata/bb/control01.ctl
oracle  2757 oracle  257uW  REG  253,0  524296192 4784160 /u01/app/oracle/oradata/bb/system01.dbf
oracle  2757 oracle  258uW  REG  253,0 1048584192 4784161 /u01/app/oracle/oradata/bb/sysaux01.dbf
oracle  2757 oracle  259u   REG  253,0  581967872 4784162 /u01/app/oracle/oradata/bb/undotbs01.dbf
oracle  2757 oracle  260u   REG  253,0   85204992 4784165 /u01/app/oracle/oradata/bb/users01.dbf
oracle  2757 oracle  261uW  REG  253,0  209723392 4784784 /u01/app/oracle/oradata/bb/ezio01.dbf
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)   可以看见文件被标识为 delete

进入dbwr进程的File Descriptor number目录中

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 64 Mar 15 23:30 9 -> /dev/null
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 8 -> /dev/null
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 7 -> /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 6 -> /dev/null
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 5 -> /dev/null
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 4 -> /dev/null
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 3 -> /dev/null
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 263 -> /test/lunar_test01.dbf (deleted)   可以看见dbwr的进程的FD号
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 262 -> /u01/app/oracle/oradata/bb/temp01.dbf
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 261 -> /u01/app/oracle/oradata/bb/ezio01.dbf
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 260 -> /u01/app/oracle/oradata/bb/users01.dbf
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 259 -> /u01/app/oracle/oradata/bb/undotbs01.dbf
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 258 -> /u01/app/oracle/oradata/bb/sysaux01.dbf
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 257 -> /u01/app/oracle/oradata/bb/system01.dbf
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 256 -> /u01/app/oracle/oradata/bb/control01.ctl
l-wx ------ 1 oracle oinstall 64 Mar 15 23:30 2 -> /dev/null
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 18 -> /u01/app/oracle/product/11.2.0.3/dbhome_1/rdbms/mesg/oraus.msb
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 17 -> /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/lkBB
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 16 -> /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 15 -> /dev/zero
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 14 -> /proc/2757/fd
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 13 -> /u01/app/oracle/product/11.2.0.3/dbhome_1/rdbms/mesg/oraus.msb
lrwx ------ 1 oracle oinstall 64 Mar 15 23:30 12 -> /u01/app/oracle/product/11.2.0.3/dbhome_1/dbs/hc_bb.dat
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 11 -> /dev/zero
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 10 -> /dev/zero
l-wx ------ 1 oracle oinstall 64 Mar 15 23:30 1 -> /dev/null
lr-x ------ 1 oracle oinstall 64 Mar 15 23:30 0 -> /dev/null
lrwx ------ 1 oracle oinstall 64 Mar 15 23:37 19 -> socket:[42951]

恢复过程

[oracle@lunar ~]$ cd /proc/2757/fd/
--根据File Descriptor number重建数据文件：
[oracle@lunar fd]$ cat 263 > /test/lunar01 .dbf

检查下，文件已经恢复完成，大小为10m

[oracle@lunar fd]$ ls -lrt /test/lunar01 .dbf
-rw-r--r-- 1 oracle oinstall 10493952 Mar 15 23:50 /test/lunar01 .dbf

将数据文件offline

SQL> alter database datafile '/test/lunar_test01.dbf' offline;

Database altered.
[/sql
修改控制文件的文件信息，因为已经将rm的/test/lunar_test01.dbf，创建到/test/lunar01.dbf，因此要同步控制文件中的信息
1
SQL> alter database rename file '/test/lunar_test01.dbf' to '/test/lunar01.dbf' ;

Database altered.

恢复datafile

SQL> recover datafile '/test/lunar01.dbf' ;
Media recovery complete.

将数据文件online

SQL> alter database datafile '/test/lunar01.dbf' online;

Database altered.

好了，完成恢复了

SQL> conn lunar/lunar
Connected.
SQL> select * from test_table;

NAME
--------------------------------------------------------------------------------
Love you forever, my baby, Happy Childrens Day !

SQL>
SQL> select tablespace_name from dba_tablespaces;

TABLESPACE_NAME
------------------------------------------------------------
SYSTEM
SYSAUX
UNDOTBS1
TEMP
USERS
EZIO
LUNAR_TEST

7 rows selected.

SQL> select name from v$datafile;

NAME
--------------------------------------------------------------------------------
/u01/app/oracle/oradata/bb/system01.dbf
/u01/app/oracle/oradata/bb/sysaux01.dbf
/u01/app/oracle/oradata/bb/undotbs01.dbf
/u01/app/oracle/oradata/bb/users01.dbf
/u01/app/oracle/oradata/bb/ezio01.dbf
/test/lunar01.dbf

6 rows selected