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一次RMAN还原慢的分析

         下面是模拟同事在客户现场遇到的RMAN还原慢的情况,同事也只能在旁边干着急因为备份与还原是由其它的备份工程师在操作,但是由于备份工程师的ORACLE技术能力,导致在还原数据库速度很慢。我们知道,RMAN备份与还原也是可以通过配置参数来提到性能,如果是通过备份软件,还可以通过调用备份软件的BUFFER来实现,多路复用等机制来优化,如果数据文件存放在ASM环境中,现在ORACLE可以自动优化RMAN相关的ORACLE参数。然后,这次同事遇到的RMAN还原慢的主要原因不是由于RMAN的参数,下面我们通过模拟要证明,是什么原因导致整个备份速度慢。

         这里将备份集存放在磁盘上,没有模拟磁带的情况。

1,环境介绍

www.htz.pw > select * from v$version;

 

BANNER

——————————————————————————–

Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 – 64bit Production

PL/SQL Release 11.2.0.3.0 – Production

CORE    11.2.0.3.0      Production

TNS for 64-bit Windows: Version 11.2.0.3.0 – Production

NLSRTL Version 11.2.0.3.0 – Production

www.htz.pw > host uname -a

windows32 luoping 2.6.1 7601 i686-pc Intel unknown MinGW

2,测试数据创建

这里创建了多个表空间,用于模拟生产环境

1,创建多个表空间

create tablespace htz01 datafile ‘D:\APP\LUOPING\ORADATA\HTZ\HTZ01.DBF’ size 10M;

.…………

create tablespace htz25 datafile ‘D:\APP\LUOPING\ORADATA\HTZ\HTZ25.DBF’ size 10M;

 

创建测试表

create table htz.htz01 tablespace htz01 as select * from dba_objects;

.……………….

create table htz.htz25 tablespace htz25 as select * from dba_objects;

3,配置归档

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup mount;

ORACLE instance started.

 

Total System Global Area  392495104 bytes

Fixed Size                  2255544 bytes

Variable Size             155190600 bytes

Database Buffers          226492416 bytes

Redo Buffers                8556544 bytes

Database mounted.

SQL> alter database archivelog;

Database altered.

SQL> alter database open;

Database altered.

4,配置备份脚本

由于备份脚本的内容太多,就不贴出来了,只贴了rman的命令

RUN {

ALLOCATE CHANNEL ch00 TYPE DISK;

ALLOCATE CHANNEL ch01 TYPE DISK;

BACKUP

      INCREMENTAL Level=0

      FORMAT ‘d:\shell\bk_u%u_s%s_p%p_t%t’

      DATABASE;

sql ‘alter system archive log current’;

RELEASE CHANNEL ch00;

RELEASE CHANNEL ch01;

# Backup all archive logs

ALLOCATE CHANNEL ch00 TYPE DISK;

BACKUP

      FILESPERSET 20

      FORMAT ‘d:\shell\arch-s%s-p%p-t%t’

      ARCHIVELOG ALL;

RELEASE CHANNEL ch00;

ALLOCATE CHANNEL ch00 TYPE DISK;

BACKUP

      FORMAT ‘d:\shell\cntrl_p_t’

      CURRENT CONTROLFILE;

RELEASE CHANNEL ch00;

}

 

d:\shell>hot_database.cmd

RMAN> 2> 3> 4> 5> 6> 7> 8> 9> 10> 11> 12> 13> 14> 15> 16> 17> 18> 19> 20> 21> 22> 23> RMAN> LOGMSGDATERMAN_LOG_FILE

rman备份日志输出内容

==== started on 2014/09/21 周日  23:53 ====

Script name: hot_database.cmd

 

Recovery Manager: Release 11.2.0.3.0 – Production on Sun Sep 21 23:53:06 2014

 

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

 

connected to target database: HTZ (DBID=1913545637)

using target database control file instead of recovery catalog

 

RMAN> 2> 3> 4> 5> 6> 7> 8> 9> 10> 11> 12> 13> 14> 15> 16> 17> 18> 19> 20> 21> 22> 23>

allocated channel: ch00

channel ch00: SID=134 device type=DISK

 

allocated channel: ch01

channel ch01: SID=199 device type=DISK

 

Starting backup at 2014-09-21:23:53:07

channel ch00: starting incremental level 0 datafile backup set

channel ch00: specifying datafile(s) in backup set

input datafile file number=00001 name=D:\APP\LUOPING\ORADATA\HTZ\SYSTEM01.DBF

input datafile file number=00012 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ08.DBF

input datafile file number=00014 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ10.DBF

input datafile file number=00016 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ12.DBF

input datafile file number=00018 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ14.DBF

input datafile file number=00020 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ16.DBF

input datafile file number=00022 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ18.DBF

input datafile file number=00023 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ19.DBF

input datafile file number=00024 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ20.DBF

input datafile file number=00025 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ21.DBF

input datafile file number=00026 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ22.DBF

input datafile file number=00027 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ23.DBF

input datafile file number=00028 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ24.DBF

input datafile file number=00029 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ25.DBF

channel ch00: starting piece 1 at 2014-09-21:23:53:07

channel ch01: starting incremental level 0 datafile backup set

channel ch01: specifying datafile(s) in backup set

input datafile file number=00002 name=D:\APP\LUOPING\ORADATA\HTZ\SYSAUX01.DBF

input datafile file number=00003 name=D:\APP\LUOPING\ORADATA\HTZ\UNDOTBS01.DBF

input datafile file number=00004 name=D:\APP\LUOPING\ORADATA\HTZ\USERS01.DBF

input datafile file number=00005 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ01.DBF

input datafile file number=00006 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ02.DBF

input datafile file number=00007 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ03.DBF

input datafile file number=00008 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ04.DBF

input datafile file number=00009 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ05.DBF

input datafile file number=00010 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ06.DBF

input datafile file number=00011 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ07.DBF

input datafile file number=00013 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ09.DBF

input datafile file number=00015 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ11.DBF

input datafile file number=00017 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ13.DBF

input datafile file number=00019 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ15.DBF

input datafile file number=00021 name=D:\APP\LUOPING\ORADATA\HTZ\HTZ17.DBF

channel ch01: starting piece 1 at 2014-09-21:23:53:08

channel ch00: finished piece 1 at 2014-09-21:23:53:23

piece handle=D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987 tag=TAG20140921T235307 comment=NONE

channel ch00: backup set complete, elapsed time: 00:00:16

channel ch00: starting incremental level 0 datafile backup set

channel ch00: specifying datafile(s) in backup set

channel ch01: finished piece 1 at 2014-09-21:23:53:23

piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307 comment=NONE

channel ch01: backup set complete, elapsed time: 00:00:15

channel ch01: starting incremental level 0 datafile backup set

channel ch01: specifying datafile(s) in backup set

including current SPFILE in backup set

channel ch01: starting piece 1 at 2014-09-21:23:53:23

including current control file in backup set

channel ch00: starting piece 1 at 2014-09-21:23:53:24

channel ch01: finished piece 1 at 2014-09-21:23:53:24

piece handle=D:\SHELL\BK_U0IPJ3JFJ_S18_P1_T858902003 tag=TAG20140921T235307 comment=NONE

channel ch01: backup set complete, elapsed time: 00:00:01

channel ch00: finished piece 1 at 2014-09-21:23:53:25

piece handle=D:\SHELL\BK_U0HPJ3JFJ_S17_P1_T858902003 tag=TAG20140921T235307 comment=NONE

channel ch00: backup set complete, elapsed time: 00:00:01

Finished backup at 2014-09-21:23:53:25

通过日志,可以看到生成了2个备份片的信息

5,还原测试

同样由于还原脚本内容太多,这里只贴了还原命令

5.1 备份工程师还原脚本模拟

RUN {

ALLOCATE CHANNEL ch00 TYPE DISK;

ALLOCATE CHANNEL ch01 TYPE DISK;

RESTORE DATAFILE 1 ;

RESTORE DATAFILE 2 ;

RESTORE DATAFILE 3 ;

RESTORE DATAFILE 4 ;

RESTORE DATAFILE 5 ;

RESTORE DATAFILE 6 ;

RESTORE DATAFILE 7 ;

RESTORE DATAFILE 8 ;

RESTORE DATAFILE 9 ;

RESTORE DATAFILE 10;

RESTORE DATAFILE 11;

RESTORE DATAFILE 12;

RESTORE DATAFILE 13;

RESTORE DATAFILE 14;

RESTORE DATAFILE 15;

RESTORE DATAFILE 16;

RESTORE DATAFILE 17;

RESTORE DATAFILE 18;

RESTORE DATAFILE 19;

RESTORE DATAFILE 20;

RESTORE DATAFILE 21;

RESTORE DATAFILE 22;

RESTORE DATAFILE 23;

RESTORE DATAFILE 24;

RESTORE DATAFILE 25;

RESTORE DATAFILE 26;

RESTORE DATAFILE 27;

RESTORE DATAFILE 28;  

RESTORE DATAFILE 29; 

RELEASE CHANNEL ch00;

RELEASE CHANNEL ch01;

}

d:\shell>restore.cmd                                                                                                                                              

RMAN> 2> 3> 4> 5> 6> 7> 8> 9> 10> 11> 12> 13> 14> 15> 16> 17> 18> 19> 20> 21> 22> 23> 24> 25> 26> 27> 28> 29> 30> 31> 32> 33> 34> 35> RMAN> LOGMSGDATERMAN_LOG_FILE

这里可以看到,每个数据文件都是一个单独的restore来还原。

下面来看看生成的日志内容

==== started on 2014/09/21 周日  23:59 ====

Script name: restore.cmd

 

Recovery Manager: Release 11.2.0.3.0 – Production on Sun Sep 21 23:59:14 2014

 

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

 

connected to target database: HTZ (DBID=1913545637, not open)

using target database control file instead of recovery catalog

 

RMAN> 2> 3> 4> 5> 6> 7> 8> 9> 10> 11> 12> 13> 14> 15> 16> 17> 18> 19> 20> 21> 22> 23> 24> 25> 26> 27> 28> 29> 30> 31> 32> 33> 34> 35>

allocated channel: ch00

channel ch00: SID=129 device type=DISK

 

allocated channel: ch01

channel ch01: SID=192 device type=DISK

 

Starting restore at 2014-09-21:23:59:15

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00001 to D:\APP\LUOPING\ORADATA\HTZ\SYSTEM01.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:07

Finished restore at 2014-09-21:23:59:23

 

……

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00007 to D:\APP\LUOPING\ORADATA\HTZ\HTZ03.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:32

 

Starting restore at 2014-09-21:23:59:32

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00008 to D:\APP\LUOPING\ORADATA\HTZ\HTZ04.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:33

 

Starting restore at 2014-09-21:23:59:33

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00009 to D:\APP\LUOPING\ORADATA\HTZ\HTZ05.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:34

 

Starting restore at 2014-09-21:23:59:34

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00010 to D:\APP\LUOPING\ORADATA\HTZ\HTZ06.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:35

 

Starting restore at 2014-09-21:23:59:35

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00011 to D:\APP\LUOPING\ORADATA\HTZ\HTZ07.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:36

 

Starting restore at 2014-09-21:23:59:36

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00012 to D:\APP\LUOPING\ORADATA\HTZ\HTZ08.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:37

 

Starting restore at 2014-09-21:23:59:37

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00013 to D:\APP\LUOPING\ORADATA\HTZ\HTZ09.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:39

 

Starting restore at 2014-09-21:23:59:39

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00014 to D:\APP\LUOPING\ORADATA\HTZ\HTZ10.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:40

 

Starting restore at 2014-09-21:23:59:40

 

channel ch00: starting datafile backup set restore

channel ch00: specifying datafile(s) to restore from backup set

channel ch00: restoring datafile 00015 to D:\APP\LUOPING\ORADATA\HTZ\HTZ11.DBF

channel ch00: reading from backup piece D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987

channel ch00: piece handle=D:\SHELL\BK_U0GPJ3JF3_S16_P1_T858901987 tag=TAG20140921T235307

channel ch00: restored backup piece 1

channel ch00: restore complete, elapsed time: 00:00:01

Finished restore at 2014-09-21:23:59:41

…………………..

其中一个备份片来看

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

channel ch00: reading from backup piece D:\SHELL\BK_U0FPJ3JF3_S15_P1_T858901987

在整个还原中,读了这么多次备份片,因为每一个restore命令就会去读还原片的信息,这就是慢的原因所在了。特别是在生产环境中,都是备份到磁带中的,还原不慢才怪。 

下面计算一下还原的时间

Starting restore at 2014-09-21:23:59:15

Finished restore at 2014-09-21:23:59:57

第一次还原使用了42S的时间,因为BUFFER的影响,多次测试,时间都差不多。

5.2 使用一条命令来还原

RUN {

ALLOCATE CHANNEL ch00 TYPE DISK;

ALLOCATE CHANNEL ch01 TYPE DISK;

RESTORE DATABASE;

RELEASE CHANNEL ch00;

RELEASE CHANNEL ch01;

}

d:\shell>restore.cmd

RMAN> 2> 3> 4> 5> 6> 7> RMAN> LOGMSGDATERMAN_LOG_FILE

后台日志内容如下:

cript name: restore.cmd

 

Recovery Manager: Release 11.2.0.3.0 – Production on Mon Sep 22 00:06:23 2014

 

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

 

connected to target database: HTZ (DBID=1913545637, not open)

using target database control file instead of recovery catalog

 

RMAN> 2> 3> 4> 5> 6> 7>

allocated channel: ch00

channel ch00: SID=129 device type=DISK

 

allocated channel: ch01

channel ch01: SID=191 device type=DISK

 

Starting restore at 2014-09-22:00:06:24

………………..

还原的时间,每一次测试

Starting restore at 2014-09-22:00:35:51

Finished restore at 2014-09-22:00:36:07

第二次测试

Starting restore at 2014-09-22:00:37:06

Finished restore at 2014-09-22:00:37:23

这里看到两次的时间都不到20S,远远小于之前的时间。

6,实验总结

在做rman还原的时候,尽量把命令写在一个restore命令中,减少对相同备份片进行重复的读取工作。另外整个实验需要注意的是:没有考虑一个数据文件写到一个备份片的情况。

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该日志由 huangtingzhong 于2014年09月22日发表在 BACKUP & RESTORE 分类下, 你可以发表评论,并在保留原文地址及作者的情况下引用到你的网站或博客。
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