小白今天登陆数据库，报错：No space left on Device，查看磁盘空间：
oracle@linux101:~>df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda1 30G 28G 2.7G 92% /
udev 12G 68K 12G 1% /dev
/dev/hda2 52G 18G 31G 37% /opt
/dev/hda3 28G 28G 0 100% /home
shm 16G 1.7G 15G 11% /dev/shm
shmfs 16G 1.7G 15G 11% /dev/shm
于是小白在/home目录下的各个目录级别下查看个文件的大小，最后锁定在$ORACLE_HOME/dbs，发现有8.2G，查看文件，找到N多的dbf文件
-rw-r----- 1 oracle dba 41974272 Dec 25 00:51 arch1_67_719519639.dbf
-rw-r----- 1 oracle dba 41977856 Dec 25 00:52 arch1_68_719519639.dbf
-rw-r----- 1 oracle dba 41981440 Dec 25 00:54 arch1_69_719519639.dbf
-rw-r----- 1 oracle dba 41974784 Dec 25 00:55 arch1_70_719519639.dbf
-rw-r----- 1 oracle dba 41989632 Dec 25 00:57 arch1_71_719519639.dbf
-rw-r----- 1 oracle dba 41976320 Dec 25 01:12 arch1_81_719519639.dbf
-rw-r----- 1 oracle dba 18632192 Dec 20 19:48 arch1_9_719519639.dbf
-rw-rw---- 1 oracle dba 1544 Dec 25 10:32 hc_ora11g.dat
-rw-r--r-- 1 oracle dba 2774 Sep 11 2007 init.ora
-rw-r--r-- 1 oracle dba 12920 May 3 2001 initdw.ora
-rw-r--r-- 1 oracle dba 1152 Dec 19 20:25 initora11g.ora
-rw-r----- 1 oracle dba 1919 Dec 19 13:47 initora11g.ora.bak
-rw-r----- 1 oracle dba 24 May 20 2010 lkORA11G
-rw-r----- 1 oracle dba 1536 May 20 2010 orapwora11g
-rw-r----- 1 oracle dba 4608 Dec 25 10:32 spfileora11g.ora
-rw-r----- 1 oracle dba 3584 Dec 19 18:43 spfileora11g.ora.bak
linux101:/home/oracle/app/product/11/db/dbs # date
Wed Dec 25 10:39:12 CST 2013
如此看来，每个arch*.dbf大小为41M，若200个,8G就被吞掉了，小白决定马上删掉归档文件~
方法一：
oracle@linux101:~>rman target/ （进入数据库的备份工具，这里的/不能省略，否则会报错）
Recovery Manager: Release 11.1.0.7.0 - Production on Wed Dec 25 13:53:11 2013
Copyright (c) 1982, 2007, Oracle. All rights reserved.
connected to target database: ORA11G (DBID=4115719763)
RMAN> DELETE ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE';
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=1051 device type=DISK
List of Archived Log Copies for database with db_unique_name ORA11G
=====================================================================
Key Thrd Seq S Low Time
------- ---- ------- - ---------
290 1 293 A 25-DEC-13
Name: /home/oracle/app/product/11/db/dbs/arch1_293_719519639.dbf
291 1 294 A 25-DEC-13
Name: /home/oracle/app/product/11/db/dbs/arch1_294_719519639.dbf
292 1 295 A 25-DEC-13
Name: /home/oracle/app/product/11/db/dbs/arch1_295_719519639.dbf
...
...
...
Do you really want to delete the above objects (enter YES or NO)? YES (需要手动输入)
deleted archived log
archived log file name=/home/oracle/app/product/11/db/dbs/arch1_293_719519639.dbf RECID=290 STAMP=835094799
deleted archived log
archived log file name=/home/oracle/app/product/11/db/dbs/arch1_294_719519639.dbf RECID=291 STAMP=835094917
deleted archived log
archived log file name=/home/oracle/app/product/11/db/dbs/arch1_295_719519639.dbf RECID=292 STAMP=835095052
...
...
...
Deleted 287 objects
RMAN>
DELETE ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE';中
若是SYSDATA-7，表明当前的系统时间7天前，before关键字表示在7天前的归档日志，如果使用了闪回功能，也会删除闪回的数据。在这里是SYSDATE,表示需要删除当天的归档日志。
方法二：
1. 以oracle用户删掉归档文件在磁盘上的存储：
find $ORACLE_HOME/dbs -xdev -mtime +7 -name "*.dbf" -exec rm -f {} ;
2. 删除在RMAN里留下未管理的归档文件
oracle@linux101:~>rman target/ # 进入数据库备份工具RMAN
Recovery Manager: Release 11.1.0.7.0 - Production on Wed Dec 25 13:53:11 2013
Copyright (c) 1982, 2007, Oracle. All rights reserved.
connected to target database: ORA11G (DBID=4115719763)
RMAN> crosscheck archivelog all;
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=1052 device type=DISK
specification does not match any archived log in the recovery catalog
RMAN> delete expired archivelog all;
released channel: ORA_DISK_1
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=1052 device type=DISK
specification does not match any archived log in the recovery catalog
RMAN>
因为是不是生产环境，不需要归档模式，现在讲归档模式关闭掉，
SQL> archive log list; # 查看是否是归档模式
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /home/oracle/app/prod
Oldest online log sequence 292
Next log sequence to archive 294
Current log sequence 294
SQL> alter system set log_archive_start=false scope=spfile; #禁用自动归档模式
System altered.
SQL> shutdown abort
ORACLE instance shut down.
SQL> startup mount; # 打开控制文件，不打开数据文件
ORACLE instance started.
Total System Global Area 2956300288 bytes
Fixed Size 2163360 bytes
Variable Size 1778388320 bytes
Database Buffers 1157627904 bytes
Redo Buffers 18120704 bytes
Database mounted.
SQL> alter database noarchivelog; # 将数据库切换为非归档模式
Database altered.
SQL> alter database open;
Database altered.
SQL> archive log list;
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /home/oracle/app/product/11/db/dbs/arch
Oldest online log sequence 295
Current log sequence 297
若要开启数据库的归档模式,跟关闭差不多，如下：
sql> alter system set log_archive_start=true scope=spfile; #启用主动归档
sql> shutdown immediate;
sql> startup mount; #打开控制文件，不打开数据文件
sql> alter database archivelog; #将数据库切换为归档模式
sql> alter database open; #将数据文件打开
sql> archive log list; #查看此时是否处于归档模式