手动归档时，alert提示ARC2: Unable to archive log

0727

做手动归档时，归档日志检查都成功了，但发现alert中有错误的提示：
SQL> alter system archive log current;

System altered.

SQL>

Thread 1 advanced to log sequence 5
  Current log# 2 seq# 5 mem# 0: /home/oracle/oradata/rac1/redo02.log
Wed Oct 18 11:00:58 2006
ARCH: Evaluating archive   log 1 thread 1 sequence 4
ARCH: Beginning to archive log 1 thread 1 sequence 4
Creating archive destination LOG_ARCHIVE_DEST_1: '/home/oracle/arch/ARC00010000000004.arc'
Wed Oct 18 11:00:58 2006
ARC2: Evaluating archive   log 1 thread 1 sequence 4
ARC2: Unable to archive log 1 thread 1 sequence 4
      Log actively being archived by another process
Wed Oct 18 11:00:59 2006
ARCH: Completed archiving  log 1 thread 1 sequence 4

弱智

查看如下结果看看是否有问题？
archive log list;

然后再看看警告日志的详细记载和相关的trace文件？

0727

archive log list 是正常的：
SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /home/oracle/arch
Oldest online log sequence     7
Next log sequence to archive   9
Current log sequence           9
SQL>

检查今天没有产生trace文件，但如果做log switch是检查alter日志是和系统自动归档的日志是一样的：
SQL> alter system switch logfile;

System altered.

SQL>

Wed Oct 18 11:35:49 2006
Thread 1 advanced to log sequence 9
  Current log# 3 seq# 9 mem# 0: /home/oracle/oradata/rac1/redo03.log
Wed Oct 18 11:35:49 2006
ARC2: Evaluating archive   log 2 thread 1 sequence 8
ARC2: Beginning to archive log 2 thread 1 sequence 8
Creating archive destination LOG_ARCHIVE_DEST_1: '/home/oracle/arch/ARC00010000000008.arc'
ARC2: Completed archiving  log 2 thread 1 sequence 8

numenhuang

这种情况出现是有可能的：
alter system archive log current 主要是用在作热备份的时候，一般情况下不建议你执行该条语句。通过alter system switch logfile一样可以达到效果。但是两条语句执行的方式是不一样的。alter system archive log current 会启动一个进程来强制作archived，但是因为数据库本身就运行在archivelog模式下，已经有缺省的arch进程运行并且也在作archived。这样两个进程就会出现有一个进程不能对同一个archive log加锁的问题。只要最后提示这个archive log archived成功，还是没有问题的。

0727

哦，好的，最后是成功的