首先感谢junsansi和leshani两位大师的文笔；我可是好好看了很多遍；这两位哦；我跟你们说；对rman的解说那是相当精彩；文章形如流水，通俗易懂；内容那是入木三分...;好了我也不多说了，反正我现在也词穷了；对一个语文不及格的来说；说了这么多成语也不容易；××费就不收你们的了；说真的很感谢这两位；反正我对rman相当的研究了。rman:(Recovery Manager);顾名思义那就是一个备份/恢复的工具；同时对迁移，克隆也是一把好手。说到迁移...DG好像有话说；暂时不让它说。
对oracle数据库备份/恢复；
- 备份还是采用rman备份的好；原因吗？因为rman就是用来备份+恢复的工具。哦???。
- rman只备份oracle用到过的数据块；可以跳过未使用的数据块；这样备份集比“物理备份”要少；比逻辑备份我就不说了
- 它能够备份整个数据库或数据库部件，如表空间、数据文件、控制文件、归档文件以及Spfile参数文件。
好处当然不只1-2点；容你慢慢去学习。
- 至于恢复吗
尽量使用flase database去恢复；如这恢复不了（这是要看你能够闪回的最晚时间；或者是文件丢失）。才去用rman去恢复。
有了完整的备份；一起都是浮云；这话说的有点大？但是备份还是不能少；
下面是一些笔记（挑选）；至于详细大家还是去看他们的博客；我这就不复制了。
1. alter system switch logfile 和 alter system archive log current 区别和含义：
alter system switch logfile 是强制日志切换，不一定就归档当前的重做日志文件（若自动归档打开，就归档前的重做日志，若自动归档没有打开，就不归档当前重做日志。）alter system archive log current 是归档当前的重做日志文件，不管自动归档有没有打都归档。
2. 备份控制文件
RMAN> backup current controlfile;
SQL>alter database backup controlfile to trace as '/data/control01.txt';
3. 密码文件
orapwd file=<fname> password=<password> entries=<users> force=<y/n>orapwd file=orapwSY5221 password=oracle force=y entries=10 --force=y:表示允许覆盖原密码文件
4. 如何查找dbid
rman target /
SQL> select dbid from v$database;
5. filesperset 和 maxpiecesize的含义
filesperset: 允许备份集文件最多有多少个。
maxpiecesize ：允许备份集最大有多少
学习rman；至少要了解oracle体系结构（必要条件）；里面的参数重在理解；能灵活运用。
例如；就三思出的那个定时备份的题目来说；我写的脚本就是这样的；
run{
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 14 DAYS;
allocate channel c1 type disk;
backup database format 'f:\oracle\backup\back_%U' plus archivelog delete all input;
delete noprompt obsolete;
release channel c1;
}
还是那句话重在理解；能灵活运用。就行。
最后奉送一个备份脚本；很完善的rman备份脚本
#!/bin/bash
# User specific environment and startup programs
if [ -f ~/.bash_profile ];
then
source ~/.bash_profile
fi
ORACLE_SID=ora11g; export ORACLE_SID
RMAN_LEVEL=${}; export RMAN_LEVEL
TIMESTAMP=`date +%Y%m%d%H%M`; export TIMESTAMP
DATE=`date +%Y%m%d`; export DATE
RMAN_DIR=/data/backup/rman; export RMAN_DIR
RMAN_DATA=${RMAN_DIR}/${DATE}; export RMAN_DATA
RMAN_LOG=/data/backup/log; export RMAN_LOG
# Check rman level
#======================================================================
if [ "$RMAN_LEVEL" == "F" ];
then unset INCR_LVL
BACKUP_TYPE=full
else
INCR_LVL="INCREMENTAL LEVEL ${RMAN_LEVEL}"
BACKUP_TYPE=lev${RMAN_LEVEL}
fi
RMAN_FILE=${RMAN_DATA}/${ORACLE_SID}_${BACKUP_TYPE}_${TIMESTAMP}; export RMAN_FILE
SSH_LOG=${RMAN_LOG}/${ORACLE_SID}_${BACKUP_TYPE}_${TIMESTAMP}.log; export SSH_LOG
MAXPIECESIZE=4G; export MAXPIECESIZE
#Check RMAN Backup Path
#=========================================================================
if ! test -d ${RMAN_DATA}
then
mkdir -p ${RMAN_DATA}
fi
echo "---------------------------------" >>${SSH_LOG}
echo " " >>${SSH_LOG}
echo "Rman Begin to Working ........." >>${SSH_LOG}
echo "Begin time at:" `date` --`date +%Y%m%d%H%M` >>${SSH_LOG}
#Startup rman to backup
#=============================================================================
$ORACLE_HOME/bin/rman log=${RMAN_FILE}.log << EOF
connect target /
run {
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF DAYS;
CONFIGURE BACKUP OPTIMIZATION ON;
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '${RMAN_FILE}_%F';
ALLOCATE CHANNEL 'ch1' TYPE DISK maxpiecesize=${MAXPIECESIZE};
ALLOCATE CHANNEL 'ch2' TYPE DISK maxpiecesize=${MAXPIECESIZE};
set limit channel ch1 readrate=;
set limit channel ch1 kbytes=;
set limit channel ch2 readrate=;
set limit channel ch2 kbytes=;
CROSSCHECK ARCHIVELOG ALL;
DELETE NOPROMPT EXPIRED ARCHIVELOG ALL;
BACKUP
${INCR_LVL}
DATABASE FORMAT '${RMAN_FILE}_%U' TAG '${ORACLE_SID}_${BACKUP_TYPE}_${TIMESTAMP}';
SQL 'ALTER SYSTEM ARCHIVE LOG CURRENT';
BACKUP ARCHIVELOG ALL FORMAT '${RMAN_FILE}_arc_%U' TAG '${ORACLE_SID}_arc_${TIMESTAMP}'
DELETE INPUT;
DELETE NOPROMPT OBSOLETE;
RELEASE CHANNEL ch1;
RELEASE CHANNEL ch2;
}
sql "alter database backup controlfile to trace as ''${RMAN_DATA}/cntl_${BACKUP_TYPE}.bak''";
exit;
EOF
RC=$?
cat ${RMAN_FILE}.log >>${SSH_LOG}
echo "Rman Stop working @ time:"`date` `date +%Y%m%d%H%M` >>${SSH_LOG}
echo >>${SSH_LOG}
echo "------------------------" >>${SSH_LOG}
echo "------ Disk Space ------" >>${SSH_LOG}
df -h >>${SSH_LOG}
echo >>${SSH_LOG}
" ]; then
echo "------ error ------" >>${SSH_LOG}
else
echo "------ no error found during RMAN backup peroid------" >>${SSH_LOG}
rm -rf ${RMAN_FILE}.log
fi
#Remove old backup than 3 days
#============================================================================
RMDIR=${RMAN_DIR}/`/bin/date +%Y%m%d -d "3 days ago"`; export RMDIR
echo >>${SSH_LOG}
echo -e "------Remove old backup than 3 days ------\n" >>${SSH_LOG}
if test -d ${RMDIR}
then
rm -rf ${RMDIR}
RC=$?
fi
echo >>${SSH_LOG}
" ]; then
echo -e "------ Remove old backup exception------ \n" >>${SSH_LOG}
else
echo -e "------ no error found during remove old backup set peroid------ \n" >>${SSH_LOG}
fi
exit