oracle 不可用

登陆em，看到预警信息：
归档程序在以下时间/行号处暂停: Fri Nov 2 12:58:58 2007/130782。

察看日志文件：
vi /oracle/app/oracle/admin/orcl/bdump/alert_orcl.log 得到一下信息：

************************************************************************
ARC0: Failed to archive thread 1 sequence 4902 (19809)
Fri Nov 2 14:02:40 2007
Errors in file /oracle/app/oracle/admin/orcl/bdump/orcl_arc1_16951.trc:
ORA-19815: 警告: db_recovery_file_dest_size 字节 (共 32212254720 字节) 已使用 100.00%, 尚有 0 字节可用。
Fri Nov 2 14:02:40 2007
************************************************************************
You have following choices to free up space from flash recovery area:
1. Consider changing RMAN RETENTION POLICY. If you are using Data Guard,
then consider changing RMAN ARCHIVELOG DELETION POLICY.
2. Back up files to tertiary device such as tape using RMAN
BACKUP RECOVERY AREA command.
3. Add disk space and increase db_recovery_file_dest_size parameter to
reflect the new space.
4. Delete unnecessary files using RMAN DELETE command. If an operating
system command was used to delete files, then use RMAN CROSSCHECK and
DELETE EXPIRED commands.
************************************************************************

首先确认系统还有空间。

[root@oracle10 orcl]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 16G 4.0G 11G 28% /
/dev/sda1 99M 15M 79M 16% /boot
none 3.0G 0 3.0G 0% /dev/shm
/dev/sda5 7.4G 2.9G 4.2G 41% /oracle
/dev/sda6 30G 23G 4.9G 83% /oracle/app/oracle/flash_recovery_area
[root@oracle10 orcl]#

然后修改系统参数，把这个参数的值增加的大一些。
SQL> show parameter db_recovery_file_dest_size

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest_size big integer 40G
SQL> alter system set db_recovery_file_dest_size=50G scope=spfile;

System altered.

此时应该可以正常备份了.继续处理

如果是删除了部分的备份文件得到磁盘空间的话：

1，做全部交叉检验

run {
allocate channel ch1 type disk;
CROSSCHECK BACKUPSET;
CROSSCHECK COPY;
}

2，删除所有失效记录

run {
allocate channel ch1 type disk;
DELETE NOPROMPT EXPIRED BACKUP;
DELETE NOPROMPT EXPIRED COPY;
}