利用oradebug释放被删除文件空间

联系:手机/微信(+86 17813235971) QQ(107644445)QQ咨询惜分飞

标题:利用oradebug释放被删除文件空间

作者:惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]

在很多时候,检查系统时候发现,由于某个Oracle的trace文件导致磁盘空间告警,因为业务需要不能让数据库down下来。这个时候你想到的方法可能是直接删除掉这个trace文件,如果是win系统,那恭喜你这样做可以解决问题;如果是linux/unix系统,那就等着事故的发生吧。在linux/unix中,如果直接rm掉oracle进程的某个文件(该进程还存在),文件句柄不会释放,即磁盘使用空间不会释放。可以通过df命名看到磁盘的空间释放释放。下面通过对lgwr进程的一系列操作,使用oradebug来释放oracle进程句柄,从而达到释放oracle某个被删除的trace文件的磁盘空间
一、查找lgwr进程的trace文件

[oracle@localhost /]$ cd $ORACLE_BASE/admin/$ORACLE_SID/bdump
[oracle@localhost bdump]$ pwd
/opt/oracle/admin/mcrm/bdump
[oracle@localhost bdump]$ ls -l|grep lgwr
-rw-r----- 1 oracle oinstall 32133 Dec 22 21:00 mcrm_lgwr_3485.trc
-rw-r----- 1 oracle oinstall  3713 Oct  8 07:13 mcrm_lgwr_3489.trc
-rw-r----- 1 oracle oinstall 22507 Mar  3 06:00 mcrm_lgwr_3598.trc
-rw-r----- 1 oracle oinstall  8441 Sep 15 10:29 mcrm_lgwr_4963.trc
[oracle@localhost bdump]$ ps -ef|grep lgwr
oracle    1056 30718  0 21:10 pts/3    00:00:00 grep lgwr
oracle    3598     1  0  2011 ?        00:04:10 ora_lgwr_mcrm
[oracle@localhost bdump]$ df |grep /opt
/dev/sda6             37798668  33312588   2534988  93% /opt
[oracle@localhost bdump]$ du -s .
948     .

从这里得出几点结论:
1.当前lgwr进程的spid为:3598
2.当前lgwr进程产生的trace文件大小为:22507B
3.包含该trace文件的分区大小使用大小为:33312588KB
4.bdump目录大小为:948KB

二、删除lgwr进程对应trace文件

[oracle@localhost bdump]$ rm mcrm_lgwr_3598.trc
[oracle@localhost bdump]$ du -s .
924     .
[oracle@localhost bdump]$ df |grep /opt
/dev/sda6             37798668  33312588   2534988  93% /opt

[oracle@localhost bdump]$ ls -l /proc/3598/fd|grep lgwr   
l-wx------ 1 oracle oinstall 64 Mar  3 20:54 2 -> /opt/oracle/admin/mcrm/bdump/mcrm_lgwr_3598.trc (deleted)

从这里得出结论:
1.bdump目录当前大小变为:924KB(大约等于948KB-22507B)
2.包含该trace文件的分区大小使用大小依然为:33312588KB(没有因为删除trace文件而释放空间)

三、释放被删除trace文件空间

[oracle@localhost bdump]$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.4.0 - Production on Sat Mar 3 21:12:41 2012

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> !ls -l /proc/3598/fd|grep lgwr  
l-wx------ 1 oracle oinstall 64 Mar  3 20:54 2 -> /opt/oracle/admin/mcrm/bdump/mcrm_lgwr_3598.trc (deleted)

SQL>  oradebug setospid 3598
Oracle pid: 6, Unix process pid: 3598, image: oracle@localhost.localdomain (LGWR)
SQL> oradebug flush;    
Statement processed.
SQL> oradebug close_trace;
Statement processed.
SQL> !ls -l /proc/3598/fd|grep lgwr  

SQL> !df |grep /opt
/dev/sda6             37798668  33312564   2535012  93% /opt

SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

从这里可以得出结论:
1.包含该trace文件的分区大小使用大小为:33312564KB(大约等于948KB-22507B)
2./proc/spid/fd下面的句柄已经释放
3.总这里可以看出使用oradebug可以真正释放oracle进程磁盘使用空间

此条目发表在 Oracle 分类目录,贴了 , 标签。将固定链接加入收藏夹。

利用oradebug释放被删除文件空间》有 1 条评论

  1. 惜分飞 说:

    另一中oradebug释放句柄方法

    [oracle@localhost ~]$ cd $ORACLE_BASE/admin/$ORACLE_SID/bdump
    [oracle@localhost bdump]$ ls -l|grep arc
    -rw-r----- 1 oracle oinstall     0 Feb  1 07:24 mcrm_arc0_3622.trc
    -rw-r----- 1 oracle oinstall     0 Feb  1 07:24 mcrm_arc1_3624.trc
    [oracle@localhost bdump]$ ps -ef|grep arc
    oracle    3622     1  0  2011 ?        00:00:16 ora_arc0_mcrm
    oracle    3624     1  0  2011 ?        00:00:17 ora_arc1_mcrm
    oracle    9354  6685  0 22:19 pts/4    00:00:00 grep arc
    [oracle@localhost bdump]$ rm mcrm_arc0_3622.trc
    [oracle@localhost bdump]$ ls -l /proc/3622/fd|grep arc
    l-wx------ 1 oracle oinstall 64 Mar  3 22:22 2 -> /opt/oracle/admin/mcrm/bdump/mcrm_arc0_3622.trc (deleted)
    [oracle@localhost bdump]$ sqlplus  / as sysdba
    
    SQL*Plus: Release 10.2.0.4.0 - Production on Sat Mar 3 22:23:36 2012
    
    Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.
    
    
    Connected to:
    Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
    With the Partitioning, OLAP, Data Mining and Real Application Testing options
    
    SQL> oradebug setospid 3622
    Oracle pid: 18, Unix process pid: 3622, image: oracle@localhost.localdomain (ARC0)
    SQL> oradebug call close 2
    Function returned 0
    SQL> exit
    Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
    With the Partitioning, OLAP, Data Mining and Real Application Testing options
    [oracle@localhost bdump]$ ls -l /proc/3622/fd|grep arc
    [oracle@localhost bdump]$