1.Oracle参考文档中关于RMAN备份压缩的描述
1）关于如何通过调整RMAN参数启用取消备份压缩功能
http://download.oracle.com/docs/cd/B19306_01/backup.102/b14192/setup004.htm#sthref229
使用关键字COMPRESSED启用RMAN压缩备份方法
RMAN> CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COMPRESSED BACKUPSET;
去掉COMPRESSED关键字取消RMAN压缩备份方法
RMAN> CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO BACKUPSET;

2）关于如何直接使用RMAN命令启用备份压缩功能
http://download.oracle.com/docs/cd/B19306_01/backup.102/b14192/bkup002.htm#BRBSC138
两条压缩备份的RMAN语句，第一条语句实现对整个数据库及归档日志进行压缩备份，第二条命令实现对1、2和4号数据文件进行压缩备份。
BACKUP AS COMPRESSED BACKUPSET DATABASE PLUS ARCHIVELOG;
BACKUP AS COMPRESSED BACKUPSET DATAFILE 1,2,4;

2.测试压缩备份
1）测试脚本
（1）具有压缩功能的测试脚本
[oracle@secdb rmanbak]$ cat test_rman_compress.sh
date
rman target / <<EOF
backup as compressed backupset full database format '/u01/app/oracle/rmanbak/full_bk1_%u%p%s.rmn';
exit;
EOF
date

（2）不含压缩功能的测试脚本
[oracle@secdb rmanbak]$ cat test_rman_nocompress.sh
date
rman target / <<EOF
CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO BACKUPSET;
backup full database format '/u01/app/oracle/rmanbak/full_bk1_%u%p%s.rmn';
exit;
EOF
date

3.执行RMAN测试脚本及结论分析
1）具有压缩功能的测试脚本执行输出结果
[oracle@secdb rmanbak]$ sh test_rman_compress.sh
Thu Jul 21 22:29:46 CST 2010

Recovery Manager: Release 10.2.0.1.0 - Production on Thu Jul 21 22:29:46 2010

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

connected to target database: SECOOLER (DBID=4067316777)

RMAN>
Starting backup at 21-JUL-10
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=152 devtype=DISK
channel ORA_DISK_1: starting compressed full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00001 name=/u01/app/oracle/oradata/secooler/system01.dbf
input datafile fno=00017 name=/u01/app/oracle/oradata/secooler/tbs_perf_01.dbf
input datafile fno=00003 name=/u01/app/oracle/oradata/secooler/sysaux01.dbf
input datafile fno=00005 name=/u01/app/oracle/oradata/secooler/example01.dbf
input datafile fno=00007 name=/u01/app/oracle/oradata/secooler/tbs_rman_catalog01.dbf
input datafile fno=00002 name=/u01/app/oracle/oradata/secooler/undotbs01.dbf
input datafile fno=00006 name=/u01/app/oracle/oradata/secooler/user_08.dbf
input datafile fno=00018 name=/u01/app/oracle/oradata/secooler/EXAMPLE1_01.dbf
input datafile fno=00019 name=/u01/app/oracle/oradata/secooler/OLTP_01.dbf
input datafile fno=00020 name=/u01/app/oracle/oradata/secooler/OLTP_02.dbf
input datafile fno=00008 name=/u01/app/oracle/oradata/secooler/tbs1.dbf
input datafile fno=00014 name=/u01/app/oracle/oradata/secooler/indx_01.dbf
input datafile fno=00016 name=/u01/app/oracle/oradata/secooler/tbs_assm_01.dbf
input datafile fno=00004 name=/u01/app/oracle/oradata/secooler/users01.dbf
channel ORA_DISK_1: starting piece 1 at 21-JUL-10
channel ORA_DISK_1: finished piece 1 at 21-JUL-10
piece handle=/u01/app/oracle/rmanbak/full_bk1_2nlje62e187.rmn tag=TAG20100721T222949 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:25
channel ORA_DISK_1: starting compressed full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00009 name=/u01/app/oracle/oradata/secooler/DATA01_02.dbf
input datafile fno=00010 name=/u01/app/oracle/oradata/secooler/DATA01_03.dbf
input datafile fno=00011 name=/u01/app/oracle/oradata/secooler/DATA01_04.dbf
input datafile fno=00012 name=/u01/app/oracle/oradata/secooler/DATA01_05.dbf
input datafile fno=00013 name=/u01/app/oracle/oradata/secooler/DATA01_01.dbf
input datafile fno=00015 name=/u01/app/oracle/oradata/secooler/lob_data01.dbf
channel ORA_DISK_1: starting piece 1 at 21-JUL-10
channel ORA_DISK_1: finished piece 1 at 21-JUL-10
piece handle=/u01/app/oracle/rmanbak/full_bk1_2olje653188.rmn tag=TAG20100721T222949 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:07
Finished backup at 21-JUL-10

Starting Control File and SPFILE Autobackup at 21-JUL-10
piece handle=/u01/app/oracle/rmanbak/cf_c-4067316777-20100721-0e comment=NONE
Finished Control File and SPFILE Autobackup at 21-JUL-10

RMAN>

Recovery Manager complete.
Thu Jul 21 22:31:30 CST 2010

2）不含压缩功能的测试脚本执行输出结果
[oracle@secdb rmanbak]$ sh test_rman_nocompress.sh
Thu Jul 21 22:39:29 CST 2010

Recovery Manager: Release 10.2.0.1.0 - Production on Thu Jul 21 22:39:29 2010

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

connected to target database: SECOOLER (DBID=4067316777)

RMAN>
using target database control file instead of recovery catalog
old RMAN configuration parameters:
CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO BACKUPSET PARALLELISM 1;
new RMAN configuration parameters:
CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO BACKUPSET PARALLELISM 1;
new RMAN configuration parameters are successfully stored

RMAN>
Starting backup at 21-JUL-10
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=152 devtype=DISK
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00001 name=/u01/app/oracle/oradata/secooler/system01.dbf
input datafile fno=00017 name=/u01/app/oracle/oradata/secooler/tbs_perf_01.dbf
input datafile fno=00003 name=/u01/app/oracle/oradata/secooler/sysaux01.dbf
input datafile fno=00005 name=/u01/app/oracle/oradata/secooler/example01.dbf
input datafile fno=00007 name=/u01/app/oracle/oradata/secooler/tbs_rman_catalog01.dbf
input datafile fno=00002 name=/u01/app/oracle/oradata/secooler/undotbs01.dbf
input datafile fno=00006 name=/u01/app/oracle/oradata/secooler/user_08.dbf
input datafile fno=00018 name=/u01/app/oracle/oradata/secooler/EXAMPLE1_01.dbf
input datafile fno=00019 name=/u01/app/oracle/oradata/secooler/OLTP_01.dbf
input datafile fno=00020 name=/u01/app/oracle/oradata/secooler/OLTP_02.dbf
input datafile fno=00008 name=/u01/app/oracle/oradata/secooler/tbs1.dbf
input datafile fno=00014 name=/u01/app/oracle/oradata/secooler/indx_01.dbf
input datafile fno=00016 name=/u01/app/oracle/oradata/secooler/tbs_assm_01.dbf
input datafile fno=00004 name=/u01/app/oracle/oradata/secooler/users01.dbf
channel ORA_DISK_1: starting piece 1 at 21-JUL-10
channel ORA_DISK_1: finished piece 1 at 21-JUL-10
piece handle=/u01/app/oracle/rmanbak/full_bk1_2tlje6kl193.rmn tag=TAG20100721T223932 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:05
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00009 name=/u01/app/oracle/oradata/secooler/DATA01_02.dbf
input datafile fno=00010 name=/u01/app/oracle/oradata/secooler/DATA01_03.dbf
input datafile fno=00011 name=/u01/app/oracle/oradata/secooler/DATA01_04.dbf
input datafile fno=00012 name=/u01/app/oracle/oradata/secooler/DATA01_05.dbf
input datafile fno=00013 name=/u01/app/oracle/oradata/secooler/DATA01_01.dbf
input datafile fno=00015 name=/u01/app/oracle/oradata/secooler/lob_data01.dbf
channel ORA_DISK_1: starting piece 1 at 21-JUL-10
channel ORA_DISK_1: finished piece 1 at 21-JUL-10
piece handle=/u01/app/oracle/rmanbak/full_bk1_2ulje6mn194.rmn tag=TAG20100721T223932 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:15
Finished backup at 21-JUL-10

Starting Control File and SPFILE Autobackup at 21-JUL-10
piece handle=/u01/app/oracle/rmanbak/cf_c-4067316777-20100721-10 comment=NONE
Finished Control File and SPFILE Autobackup at 21-JUL-10

RMAN>

Recovery Manager complete.
Thu Jul 21 22:41:06 CST 2010

3）比较时间消耗
从elapsed time可以得出以下信息：
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:25
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:07

channel ORA_DISK_1: backup set complete, elapsed time: 00:01:05
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:15

启用压缩耗时：  00:01:25 + 00:00:07 = 00:01:32
未启用压缩耗时：00:01:05 + 00:00:15 = 00:01:20

结论：启用压缩备份耗时略有增加（在数据量较大的环境下这个时间差会比较大）。

4）从top监控CPU使用率上进行比较
启用压缩备份期间CPU使用率监控结果
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 4972 oracle    25   0  424m  52m  23m R 65.4  0.6   0:32.62 oracle

未启用压缩备份期间CPU使用率监控结果
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 5902 oracle    25   0  423m  47m  25m R 33.1  0.6   0:09.17 oracle

结论：启用压缩CPU使用率在65.4%左右，未启用时的CPU使用率在33.1%左右。差别很明显，启用压缩将消耗更多的CPU资源。

5）比较生成的备份集大小
压缩备份集大小
[oracle@secdb rmanbak]$ du -sm /u01/app/oracle/rmanbak/full_bk1_2nlje62e187.rmn
168     /u01/app/oracle/rmanbak/full_bk1_2nlje62e187.rmn

未压缩备份集大小
[oracle@secdb rmanbak]$ du -sm /u01/app/oracle/rmanbak/full_bk1_2tlje6kl193.rmn
951     /u01/app/oracle/rmanbak/full_bk1_2tlje6kl193.rmn

结论：启用压缩功能，备份集大小是168M，而未启用压缩功能的备份集大小有951M大，是压缩备份集的5.7倍。这就是压缩备份带来的最大好处。

4.小结
使用RMAN备份压缩技术可以在很大程度上节省存储备份的空间，是典型的以时间和CPU换取空间的做法。如果系统有合理的备份窗口，不妨将这项技术引入到日常备份中去。

Good luck.

secooler
10.07.21

-- The End --

【RMAN】使用RMAN的 Compressed Backupsets备份压缩技术 （转载）的更多相关文章

  1. rman实验——测试备份压缩

    oracle rman自带的备份压缩机制,可以有效的压缩备份的大小,降低磁盘的占用率.但是也会因为压缩而消耗更多的系统性能,和增加备份时间.现在就通过实验来看压缩和不压缩的区别. 进行不压缩全备 RM ...

  2. 【RMAN】RMAN脚本中使用替换变量

    [RMAN]RMAN脚本中使用替换变量--windows 下rman全备脚本 一.1  BLOG文档结构图 一.2  前言部分 一.2.1  导读 各位技术爱好者,看完本文后,你可以掌握如下的技能,也 ...

  3. 【RMAN】RMAN跨版本恢复(下)--大版本异机恢复

    [RMAN]RMAN跨版本恢复(下)--大版本异机恢复 BLOG文档结构图 ORACLE_SID=ORA1024G 关于10g的跨小版本恢复参考:http://blog.chinaunix.net/u ...

  4. rman catalog (rman 恢复目录)

    受控制文件大小的限制,一般rman需要用rman catalog来管理及存放备份信息: 这里介绍一下创建rman catalog的步骤: C:\Documents andSettings\Admini ...

  5. [Oracle][RMAN] Use RMAN to Migrate database from CentOS_5-11201-SingleDB to OracleLinux_5-11204-SingleDB

    リンク:How to Move/Restore DB to New Host and File System using RMAN (Doc ID 1338193.1)https://docs.ora ...

  6. sql server数据库备份压缩拷贝实例

    --数据库备份压缩拷贝实例:前提要安装RAR压缩软件--声明变量declare @day varchar(10),@dbname varchar(20),@filename varchar(100), ...

  7. MongoDB 如何实现备份压缩

    背景及原理 数据库的备份是灾难恢复的最后一道屏障,不管什么类型的数据库都需要设置数据库备份,MongoDB也不例外.MongoDB 3.0 后 ,数据库可以采用Wiredtiger存储引擎后(3.2 ...

  8. 云计算之路-试用Azure：数据库备份压缩文件在虚拟机上的恢复速度测试

    测试环境:Windows Azure上海机房,虚拟机配置为大型(四核,7 GB 内存),磁盘情况见下图. 数据库备份压缩文件大于为12.0 GB (12,914,327,552 bytes),放置于T ...

  9. linux下的nginx日志自动备份压缩--日志切割机

    部署完毕nginx之后,发现自己的/var/log/nginx/*log的日志不会压缩,一直都是一个文本写日志, 时间久了,日志文件内存过于增加,将会导致在日志添加过程效率降低,延长时间. 默认安装的 ...

随机推荐

  1. python 读取excel数据并将测试结果填入Excel

    python 读取excel数据并将测试结果填入Excel 读取一个Excel中的一条数据用例,请求接口,然后返回结果并反填到excel中.过程中会生成请求回来的文本,当然还会生成一个xml文件.具体 ...

  2. Hibernate框架第三天

    **课程回顾:Hibernate第二天** 1. 持久化类和一级缓存 * 持久化类:JavaBean + 映射的配置文件 * 持久化对象的三种状态 * 瞬时态 * 持久态:有自动更新数据的能力 * 托 ...

  3. c++中istream类型到bool类型的隐式转换

    事情的起因是见到了这种用法: while(cin>>m>>n&&m&&n) { } 现在分析一下,cin>>m>>n返回 ...

  4. Unity shader学习之反射

    shader如下: Shader "Custom/Reflection" { Properties { _Cubemap("Cubemap", Cube) = ...

  5. html5-css渐变应用小实例，按钮

    .but1{    padding: 10px 20px;    font-size: 16px;    text-shadow: 2px 2px 3px rgba(0,0,0,0.8);    bo ...

  6. 利用JavaCSV API来读写csv文件

    http://blog.csdn.net/loongshawn/article/details/53423121 http://javacsv.sourceforge.net/ 转载请注明来源-作者@ ...

  7. CSS选择符-----伪类选择符

    Element:hover E:hover { sRules }  设置元素在其鼠标悬停时的样式 <!DOCTYPE html> <html> <head> < ...

  8. python 修改xml文档 ing

    原xml文件 <?xml version="1.0" encoding="utf-8"?> <catalog> <maxid> ...

  9. Linux基础命令---文本显示tac

    tac 将指定文件中的行,按照反序方式显示.此命令的适用范围:RedHat.RHEL.Ubuntu.CentOS.SUSE.openSUSE.Fedora. 1.语法         tac [选项] ...

  10. php ci nginx 伪静态rewrite配置方法

    php ci nginx 伪静态rewrite配置方法 location / { if (!-e $request_filename) { rewrite ^(.*)$ /index.php?s=/$ ...