lsof恢复oracle误删除文件例子

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最新推荐文章于 2025-05-25 23:11:34 发布

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[i=s] 本帖最后由 java3344520 于 2012-9-20 16:20 编辑

大家讨论下，看看还有什么误删的恢复例子，这个系统级别的恢复要求进程没有结束，如果结束了就找不到相应的信息了。
8、lsof恢复oracle误删除文件例子 8.1 查看ORACLE运行的进程

[oracle@xml-ora1 ~]$ uname -a

Linux xml-ora1 2.6.18-194.el5 #1 SMP TueMar 16 21:52:39 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux

[oracle@xml-ora1 ~]$ cat /etc/redhat-release

Red Hat Enterprise Linux Server release 5.5(Tikanga)

[oracle@xml-ora1 ~]$ ps -ef | grep ora_

oracle 23923 23896 0 09:43 pts/3 00:00:00 grep ora_

oracle 25342 1 0 Aug06 ? 00:00:52 ora_pmon_xmlgis

oracle 25344 1 0 Aug06 ? 00:00:00 ora_psp0_xmlgis

oracle 25346 1 0 Aug06 ? 00:00:00 ora_mman_xmlgis

oracle 25348 1 0Aug06 ? 00:00:13 ora_dbw0_xmlgis

8.2 创建测试环境

创建表空间、表、数据以及数据文件：

SQL> create tablespace test_del datafile '/u01/app/oracle/oradata/xmlgis/test_del.dbf'size 50m;

Tablespace created.

SQL> select file_name from dba_data_files where file_name like'%del%';

FILE_NAME

--------------------------------------------------------------------------------

/u01/app/oracle/oradata/xmlgis/test_del.dbf

SQL> select name from v$datafile where name like '%del%';

NAME

--------------------------------------------------------------------------------

/u01/app/oracle/oradata/xmlgis/test_del.dbf

SQL> create table test_del tablespace test_del as select * from dba_objects;

Table created.

SQL> commit;

Commit complete.

SQL> alter system checkpoint;

System altered.

SQL> select count(*) from test_del;

COUNT(*)

----------

51459

SQL>select OWNER,OBJECT_NAME from test_del WHERE OWNER<>'SYS' AND ROWNUM<3;

OWNER OBJECT_NAME

--------------------------------------------------------------------------------

PUBLIC DUAL

PUBLIC SYSTEM_PRIVILEGE_MAP

[oracle@xml-ora1 ~]$ strings/u01/app/oracle/oradata/xmlgis/test_del.dbf | grep"SYSTEM_PRIVILEGE_MAP"

SYSTEM_PRIVILEGE_MAP

I_SYSTEM_PRIVILEGE_MAP

SYSTEM_PRIVILEGE_MAP

8.3 查看dbwr0打开的数据文件

[oracle@xml-ora1 ~]$ lsof -a -p 25348 -d ^txt | egrep"COMMAND|dbf"

Output information may be incomplete.

COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME

oracle 25348 oracle 18uW REG 8,8 566239232 105186656 /u01/app/oracle/oradata/xmlgis/system01.dbf

…..省略其它文件…..

oracle 25348 oracle 48uW REG 8,8 52436992 21364739 /u01/app/oracle/oradata/xmlgis/test_del.dbf

8.4 删除test_del.dbf数据文件

SQL> !

[oracle@xml-ora1 ~]$ ll/u01/app/oracle/oradata/xmlgis/test_del.dbf

-rw-r----- 1 oracle oinstall 52436992 Sep20 14:17 /u01/app/oracle/oradata/xmlgis/test_del.dbf

[oracle@xml-ora1 ~]$ rm/u01/app/oracle/oradata/xmlgis/test_del.dbf

[oracle@xml-ora1 ~]$ ll/u01/app/oracle/oradata/xmlgis/test_del.dbf

ls:/u01/app/oracle/oradata/xmlgis/test_del.dbf: No such file or directory

[oracle@xml-ora1 ~]$ exit

Exit

SQL> select file_name from dba_data_files where file_name like'%del%';

FILE_NAME

--------------------------------------------------------------------------------

/u01/app/oracle/oradata/xmlgis/test_del.dbf

SQL> select name from v$datafile where name like '%del%';

NAME

--------------------------------------------------------------------------------

/u01/app/oracle/oradata/xmlgis/test_del.dbf

SQL> insert into test_del select * from dba_objects;

51459 rows created.

SQL> commit;

Commit complete.

SQL> select count(*) from test_del;

COUNT(*)

----------

102918

SQL> alter system checkpoint;

System altered.

SQL> create table test_del_new tablespace test_del as select * from dba_objects;

Table created.

操作正常，说明数据文件虽然被删除，但是可以继续写入，说明可以恢复。但是注意，不能关掉DBWR0进行，重新启动后将丢失文件描述符，则无法恢复。

8.5 删除文件描述符查找

[oracle@xml-ora1 ~]$ lsof | grep test_del

oracle 25348 oracle 48uW REG 8,8 52436992 21364739 /u01/app/oracle/oradata/xmlgis/test_del.dbf (deleted)

oracle 25350 oracle 30u REG 8,8 52436992 21364739 /u01/app/oracle/oradata/xmlgis/test_del.dbf (deleted)

oracle 25356 oracle 45u REG 8,8 52436992 21364739 /u01/app/oracle/oradata/xmlgis/test_del.dbf (deleted)

oracle 25358 oracle 44u REG 8,8 52436992 21364739 /u01/app/oracle/oradata/xmlgis/test_del.dbf (deleted)

oracle 32244 oracle 15u REG 8,8 52436992 21364739 /u01/app/oracle/oradata/xmlgis/test_del.dbf (deleted)

oracle 32244 oracle 19u REG 8,8 52436992 21364739 /u01/app/oracle/oradata/xmlgis/test_del.dbf (deleted)

注意：/u01/app/oracle/oradata/xmlgis/test_delete.dbf(deleted)说明该数据库文件被删除了，但是却出现了这么多是描述符号。仔细看了下其中的信息，发现PID为25348的才是DBWR0进行写入的文件，同时48uW也说明了是原来删除的文件，那其它信息呢，根据PID去查找进程。得到如下信息

[oracle@xml-ora1 ~]$ ps -ef | egrep"25348|25350|25356|25358|32244" | grep -v egrep

oracle 25348 1 0Aug06 ? 00:00:13 ora_dbw0_xmlgis

oracle 25350 1 0 Aug06 ? 00:00:22 ora_dbw1_xmlgis

oracle 25356 1 0 Aug06 ? 00:02:29 ora_ckpt_xmlgis

oracle 25358 1 0 Aug06 ? 00:01:33 ora_smon_xmlgis

oracle 32244 32243 0 12:58 ? 00:00:03 oraclexmlgis(DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))

原来除了DBWR0对该进程进行读写，还包括DBWR1,CKPT,SMON以及我当前连接的session进行读写。哪个才是要恢复的文件呢？

8.6 查看/proc文件系统

Cd /proc/819/fd/ 就可以得到所要查找的数据

[oracle@xml-ora1 ~]$ ll /proc/25348/fd/* | grep test_del

lrwx------ 1 oracle oinstall 64 Sep 2014:15 /proc/25348/fd/48-> /u01/app/oracle/oradata/xmlgis/test_del.dbf (deleted)

看来他们都是对同一个文件进行打开，只是返回的值不同而且，而真正打开该文件的是DBWR0，恢复该文件即可。