操作系统： RedHat EL55
案例：
客户数据库服务器的归档日志空间被塞满，未发现；DBA在发现日志切换被hang后，强制关了库，导致实例启动失败。
错误现象：
在做日志归档时，数据库被hang......
16:56:02 SYS@ prod>alter system switch logfile;
告警日志：
ORACLE Instance prod - Can not allocate log, archival required
Thread 1 cannot allocate new log, sequence 5
All online logs needed archiving
Current log# 1 seq# 4 mem# 0: /dsk1/oradata/prod/redo01a.log
Current log# 1 seq# 4 mem# 1: /dsk2/oradata/prod/redo01b.log
用户强制关库，重新启动：
16:37:38 SYS@ prod>startup
ORACLE instance started.
Total System Global Area 835104768 bytes
Fixed Size 2217952 bytes
Variable Size 775948320 bytes
Database Buffers 54525952 bytes
Redo Buffers 2412544 bytes
Database mounted.
ORA-03113: end-of-file on communication channel
Process ID: 13219
Session ID: 1 Serial number: 5
Instance 启动失败，告警日志提示：
Errors in file /u01/app/oracle/diag/rdbms/prod/prod/trace/prod_ora_11803.trc:
ORA-19502: write error on file "/dsk4/arch_prod/arch_1_79_827494678.log", block number 4097 (block size=512)
ORA-27072: File I/O error
Linux-x86_64 Error: 25: Inappropriate ioctl for device
Additional information: 4
Additional information: 4097
Additional information: 765440
ORA-19502: write error on file "/dsk4/arch_prod/arch_1_79_827494678.log", block number 4097 (block size=512)
Sun May 18 15:32:58 2014
ARC3 started with pid=23, OS id=11818
Errors in file /u01/app/oracle/diag/rdbms/prod/prod/trace/prod_ora_11803.trc:
ORA-19502: write error on file "/dsk4/arch_prod/arch_1_79_827494678.log", block number 4097 (block size=512)
ORA-27072: File I/O error
Linux-x86_64 Error: 25: Inappropriate ioctl for device
Additional information: 4
Additional information: 4097
Additional information: 765440
ORA-19502: write error on file "/dsk4/arch_prod/arch_1_79_827494678.log", block number 4097 (block size=512)
ARCH: I/O error 19502 archiving log 1 to '/dsk4/arch_prod/arch_1_79_827494678.log'
ARC1: Becoming the heartbeat ARCH
Errors in file /u01/app/oracle/diag/rdbms/prod/prod/trace/prod_ora_11803.trc:
ORA-16038: log 1 sequence# 79 cannot be archived
ORA-19502: write error on file "", block number (block size=)
ORA-00312: online log 1 thread 1: '/dsk1/oradata/prod/redo01a.log'
ORA-00312: online log 1 thread 1: '/dsk2/oradata/prod/redo01b.log'
USER (ospid: 11803): terminating the instance due to error 16038
Instance terminated by USER, pid = 11803
解决方法：
[oracle@rh6 prod]$ sqlplus '/as sysdba'
SQL*Plus: Release 11.2.0.1.0 Production on Sun May 18 16:39:26 2014
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
16:39:27 SYS@ prod>startup mount;
ORACLE instance started.
Total System Global Area 835104768 bytes
Fixed Size 2217952 bytes
Variable Size 775948320 bytes
Database Buffers 54525952 bytes
Redo Buffers 2412544 bytes
Database mounted.
16:39:39 SYS@ prod>select group#,sequence#,status from v$log;
GROUP# SEQUENCE# STATUS
---------- ---------- ----------------
1 1 INACTIVE
3 3 CURRENT
2 2 INACTIVE
Elapsed: 00:00:00.06
Clear 未归档的日志组：
16:40:25 SYS@ prod>alter database clear logfile group 1;
alter database clear logfile group 1
*
ERROR at line 1:
ORA-00350: log 1 of instance prod (thread 1) needs to be archived
ORA-00312: online log 1 thread 1: '/dsk1/oradata/prod/redo01a.log'
ORA-00312: online log 1 thread 1: '/dsk2/oradata/prod/redo01b.log'
Elapsed: 00:00:00.02
16:40:47 SYS@ prod>alter database clear unarchived logfile group 1;
Database altered.
Elapsed: 00:00:02.46
16:41:02 SYS@ prod>alter database open;
Database altered.
Elapsed: 00:00:06.89
再次归档：
17:26:02 SYS@ prod>alter system switch logfile;
再次hang。。。。。
查看日志：
ORACLE Instance prod - Can not allocate log, archival required
Thread 1 cannot allocate new log, sequence 5
All online logs needed archiving
Current log# 1 seq# 4 mem# 0: /dsk1/oradata/prod/redo01a.log
Current log# 1 seq# 4 mem# 1: /dsk2/oradata/prod/redo01b.log
ARC3: Encountered disk I/O error 19502
ARC3: Closing local archive destination LOG_ARCHIVE_DEST_1: '/dsk4/arch_prod/arch_1_2_847900609.log' (error 19502) (prod)
Errors in file /u01/app/oracle/diag/rdbms/prod/prod/trace/prod_arc3_13316.trc:
ORA-19502: write error on file "/dsk4/arch_prod/arch_1_2_847900609.log", block number 4097 (block size=512)
ORA-27072: File I/O error
Linux-x86_64 Error: 25: Inappropriate ioctl for device
Additional information: 4
Additional information: 4097
Additional information: 765440
查看归档日志存储空间：
16:41:16 SYS@ prod>
[root@rh6 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 18G 5.0G 12G 30% /
tmpfs 878M 72K 878M 1% /dev/shm
/dev/sda1 2.0G 62M 1.8G 4% /boot
/dev/sda3 12G 5.7G 5.3G 52% /u01
......
/dev/mapper/datavg-lv_dsk4
4.0G 3.8G 2.8M 100% /dsk4
竟然，归档日志存储空间已经被塞满，所以造成归档被hang。。。。。。
清理存储空间：
调整归档位置：
6:49:44 SYS@ prod>alter system set log_archive_dest_2='location=/dsk4/arch1';
System altered.
16:51:15 SYS@ prod>alter system set log_archive_dest_state_1=defer;
System altered.
Elapsed: 00:00:00.04
16:51:25 SYS@ prod>alter system switch logfile;
重新进行归档，归档成功！
ALTER SYSTEM SET log_archive_dest_2='location=/dsk4/arch1' SCOPE=BOTH;
Sun May 18 16:51:25 2014
Using STANDBY_ARCHIVE_DEST parameter default value as /dsk4/arch1
ALTER SYSTEM SET log_archive_dest_state_1='DEFER' SCOPE=BOTH;
Sun May 18 16:53:13 2014
Archived Log entry 4 added for thread 1 sequence 2 ID 0xf7a7caa dest 2:
krse_arc_driver_core: Successful archiving of previously failed ORL
Sun May 18 16:53:13 2014
Thread 1 advanced to log sequence 5 (LGWR switch)
Current log# 2 seq# 5 mem# 0: /dsk1/oradata/prod/redo02a.log
Current log# 2 seq# 5 mem# 1: /dsk2/oradata/prod/redo02b.log
Sun May 18 16:53:14 2014
Archived Log entry 5 added for thread 1 sequence 4 ID 0xf7a7caa dest 2:
Sun May 18 16:53:15 2014
Archived Log entry 6 added for thread 1 sequence 3 ID 0xf7a7caa dest 2:
@至此，问题彻底解决，对于归档日志的存储空间在巡检中一定要进行监控，否则空间满后，会给数据库带来很大的麻烦！
Oracle 联机重做日志文件(ONLINE LOG FILE)