本文共 5755 字，大约阅读时间需要 19 分钟。
Oracle下rm 删除数据文件恢复
下面是整个测试步骤 1.在数据库open的时候，直接删除test表空间中的数据文件 Last login: Tue Feb 7 10:24:27 2017 from 192.168.36.103 [root@oracle1 ~]# su - oracle ocrl:/home/oracle@oracle1>ps -ef |grep pmon oracle 6098 1 0 Feb07 ? 00:00:05 ora_pmon_ocrl oracle 18634 18603 0 11:34 pts/1 00:00:00 grep pmon ocrl:/home/oracle@oracle1>sqlplus / as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Fri Feb 10 11:36:15 2017 Copyright (c) 1982, 2014, Oracle. All rights reserved. Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options SQL> select name from v$datafile; NAME -------------------------------------------------------------------------------- /data/oradata/ocrl/datafile/system01.dbf /data/oradata/ocrl/datafile/sysaux01.dbf /data/oradata/ocrl/datafile/undotbs01.dbf /data/oradata/ocrl/datafile/users01.dbf /data/oradata/ocrl/datafile/test.dbf SQL> exit Disconnected from Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options ocrl:/home/oracle@oracle1>cd /data/oradata/ocrl/datafile/ ocrl:/data/oradata/ocrl/datafile@oracle1>ls sysaux01.dbf system01.dbf test.dbf undotbs01.dbf users01.dbf ocrl:/data/oradata/ocrl/datafile@oracle1>rm -rf test.dbf ocrl:/data/oradata/ocrl/datafile@oracle1>ls sysaux01.dbf system01.dbf undotbs01.dbf users01.dbf ocrl:/data/oradata/ocrl/datafile@oracle1>sqlplus / as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Fri Feb 10 11:37:23 2017 Copyright (c) 1982, 2014, Oracle. All rights reserved. Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options 2.尝试在tets表中间中创建表，开始报错 SQL> create table t tablespace test as select * from dual; create table t tablespace test as select * from dual * ERROR at line 1: ORA-01116: error in opening database file 5 ORA-01110: data file 5: '/data/oradata/ocrl/datafile/test.dbf' ORA-27041: unable to open file Linux-x86_64 Error: 2: No such file or directory Additional information: 3 SQL> exit 3.检查dbwr的进程PID ocrl:/data/oradata/ocrl/datafile@oracle1>ps -ef|grep dbw0 oracle 6121 1 0 Feb07 ? 00:00:32 ora_dbw0_ocrl oracle 19015 18603 0 11:52 pts/1 00:00:00 grep dbw0 4.dbwr会打开所有数据文件的句柄，在proc目录中可以查到，目录是进程PID，fd表示文件描述符 ocrl:/data/oradata/ocrl/datafile@oracle1>cd /proc/6121/fd ocrl:/proc/6121/fd@oracle1>ls -l total 0 lr-x------ 1 oracle dba 64 Feb 7 10:11 0 -> /dev/null l-wx------ 1 oracle dba 64 Feb 7 10:11 1 -> /dev/null l-wx------ 1 oracle dba 64 Feb 7 10:11 2 -> /dev/null lrwx------ 1 oracle dba 64 Feb 7 10:11 256 -> /data/oradata/ocrl/control/control01.ctl lrwx------ 1 oracle dba 64 Feb 7 10:11 257 -> /data/oradata/ocrl/control/control02.ctl lrwx------ 1 oracle dba 64 Feb 10 11:42 258 -> /data/oradata/ocrl/datafile/system01.dbf lrwx------ 1 oracle dba 64 Feb 10 11:42 259 -> /data/oradata/ocrl/datafile/sysaux01.dbf lrwx------ 1 oracle dba 64 Feb 10 11:42 260 -> /data/oradata/ocrl/datafile/undotbs01.dbf lrwx------ 1 oracle dba 64 Feb 10 11:42 261 -> /data/oradata/ocrl/datafile/users01.dbf lrwx------ 1 oracle dba 64 Feb 10 11:42 262 -> /data/oradata/ocrl/datafile/test.dbf (deleted) lrwx------ 1 oracle dba 64 Feb 10 11:42 263 -> /data/oradata/ocrl/tempfile/temp01.dbf lr-x------ 1 oracle dba 64 Feb 7 10:11 3 -> /dev/null lr-x------ 1 oracle dba 64 Feb 7 10:11 4 -> /u01/app/oracle/product/12.1.0/db_1/rdbms/mesg/oraus.msb lr-x------ 1 oracle dba 64 Feb 7 10:11 5 -> /proc/6121/fd lrwx------ 1 oracle dba 64 Feb 7 10:11 6 -> /u01/app/oracle/product/12.1.0/db_1/dbs/hc_ocrl.dat l-wx------ 1 oracle dba 64 Feb 7 10:11 7 -> /u01/app/oracle/product/12.1.0/db_1/rdbms/mesg/oraus.msblrwx------ 1 oracle dba 64 Feb 7 10:11 9 -> /u01/app/oracle/product/12.1.0/db_1/dbs/lkOCRL
注意：注意其中“/data/oradata/ocrl/datafile/test.dbf (deleted)”字样，表示该文件已经被删除 5.直接cp该句柄文件名回原位置 ocrl:/proc/6121/fd@oracle1>cp 262 /data/oradata/ocrl/datafile/test.dbf ocrl:/proc/6121/fd@oracle1>ls 0 1 2 256 257 258 259 260 261 262 263 3 4 5 6 7 9 ocrl:/proc/6121/fd@oracle1>cd /data/oradata/ocrl/tempfile/ ocrl:/data/oradata/ocrl/tempfile@oracle1>cd /data/oradata/ocrl/datafile/ ocrl:/data/oradata/ocrl/datafile@oracle1>ls sysaux01.dbf system01.dbf test.dbf undotbs01.dbf users01.dbf 6.进行数据文件recover--在归档模式下 ocrl:/data/oradata/ocrl/datafile@oracle1>sqlplus / as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Fri Feb 10 11:44:24 2017 Copyright (c) 1982, 2014, Oracle. All rights reserved. Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options SQL> alter database datafile 5 offline; Database altered. SQL> recover datafile 5; Media recovery complete. SQL> alter database datafile 5 online; Database altered. SQL> select file#,name from v$datafile; FILE# ---------- NAME -------------------------------------------------------------------------------- 1 /data/oradata/ocrl/datafile/system01.dbf 2 /data/oradata/ocrl/datafile/sysaux01.dbf 3 /data/oradata/ocrl/datafile/undotbs01.dbf FILE# ---------- NAME -------------------------------------------------------------------------------- 4 /data/oradata/ocrl/datafile/users01.dbf 5 /data/oradata/ocrl/datafile/test.dbf SQL> create table t tablespace test as select * from dual; Table created. SQL> select * from t; D - X SQL> exit 至此完成数据文件恢复 在非归档模式下,需要shutdown后,进入mount模式,offline,recover,online,open 恢复的原理是，在Linux操作系统中，如果文件从操作系统级别被rm掉，之前打开该文件的进程仍然持有相应的文件句柄，所指向的文件仍然可以读写，并且该文件的文件描述符可以从/proc目录中获得。但是要注意的是，此时如果关闭数据库，则此句柄会消失，那么除了扫描磁盘进行文件恢复之外就没有其它方法了，因此在数据库出现问题的时候，如果不确认情况的复杂程度，千万不要随便关闭数据库。重启数据库往往是没有意义的，甚至是致命的转载地址：http://jkhji.baihongyu.com/