xiaohao 2011-02-26
一. 一些准备知识
Oracle 分归档和非归档模式。 这两者的区别就是对redo log的处理。归档模式下,当一个redo log 写满之后,就会把这个redo log里的内容写入归档文件,等写完之后,这个redo log 就可以继续使用,如果是非归档模式下,redo log 就直接覆盖了。 恢复一般都需要归档文件,这里面记录了对数据库的操作,所以生产库一般都运行在归档模式下。 关于归档模式和非归档模式的切换参考Blog:
Oracle 归档与非归档的切换
RMAN 备份的存放位置也有2种选择,一种是直接备份到磁盘,另一种就是备份到磁带。 现在的大公司,一般都使用Symnatec Veritas NetBackup 软件来进行备份。 这款软件扩展了RMAN的功能和优点,所有用起来比较方便。 08年刚工作的时候就遇到了一个安装NetBackup的实战机会,可惜那时刚接触Oracle,连Oracle 都不了解,更不提NetBackup了, 转眼2年过去了,在也没有遇到这样的机会,不知道什么时候才能玩玩NetBackup。 遗憾啊。
使用RMAN 备份也分catalog 和nocatalog,就是是否使用恢复目录,如果不使用恢复目录,那么就是用control file作为catalog,每一次备份都要往控制文件里面写好多备份信息,控制文件里面会有越来越多的备份信息。因此,当使用rman nocatalog方式备份时,备份controlfile是非常重要的。 如果使用catalog模式,就需要句需要创建catalog目录。 当库比较多时,使用catalog也是比较方便的。
RMAN的备份也分两种,一种是全备,另一种增量备份。 全备适用与数据库比较小的情况,如果库大的话就需要使用增量备份了,因为这样能减少备份的时间。
修改控制文件的保存时间,从默认的7天改成14天
SQL> show parameter control
SQL> alter system set control_file_record_keep_time=14 scope=both;
开启控制文件的自动备份,开启之后在数据库备份或者数据文件(比如添加数据文件)有修改的时候都会自动备份控制文件和spfile文件。
Configure controlfile autobackup on;
当数据库兼容性设置为大于等于10.0.0时,尽管在没有0级备份情况做1级的增量备份实际上是一个全备,但是这个全备也是1级的,不能用作1级积累增量备份的基础备份,这个是在设计备份策略的时候要注意的问题。
二. 全备脚本
以 nocatalog 模式为例:
Shell 脚本:
########################################################################
## hot_database_backup.sh ##
## created by Tianlesoftware ##
## 2010-7-16 ##
#########################################################################
#!/bin/sh
# ---------------------------------------------------------------------------
# Determine the user which is executing this script.
# ---------------------------------------------------------------------------
CUSER=`id |cut -d"(" -f2 | cut -d ")" -f1`
# ---------------------------------------------------------------------------
# Put output in <this file name>.out. Change as desired.
# Note: output directory requires write permission.
# ---------------------------------------------------------------------------
RMAN_LOG_FILE=${0}.out
# ---------------------------------------------------------------------------
# You may want to delete the output file so that backup information does
# not accumulate. If not, delete the following lines.
# ---------------------------------------------------------------------------
if [ -f "$RMAN_LOG_FILE" ]
then
rm -f "$RMAN_LOG_FILE"
fi
# -----------------------------------------------------------------
# Initialize the log file.
# -----------------------------------------------------------------
echo >> $RMAN_LOG_FILE
chmod 666 $RMAN_LOG_FILE
# ---------------------------------------------------------------------------
# Log the start of this script.
# ---------------------------------------------------------------------------
echo Script $0 >> $RMAN_LOG_FILE
echo ==== started on `date` ==== >> $RMAN_LOG_FILE
echo >> $RMAN_LOG_FILE
# ---------------------------------------------------------------------------
# Oracle home path.
# ---------------------------------------------------------------------------
ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1
export ORACLE_HOME
# ---------------------------------------------------------------------------
# the Oracle SID of the target database.
# ---------------------------------------------------------------------------
ORACLE_SID=orcl
export ORACLE_SID
# ---------------------------------------------------------------------------
# The Oracle DBA user id (account).
# ---------------------------------------------------------------------------
ORACLE_USER=oracle
export ORACLE_USER
# ---------------------------------------------------------------------------
# Set the Oracle Recovery Manager name.
# ---------------------------------------------------------------------------
RMAN=$ORACLE_HOME/bin/rman
# ---------------------------------------------------------------------------
# Print out the value of the variables set by this script.
# ---------------------------------------------------------------------------
echo >> $RMAN_LOG_FILE
echo "RMAN: $RMAN" >> $RMAN_LOG_FILE
echo "ORACLE_SID: $ORACLE_SID" >> $RMAN_LOG_FILE
echo "ORACLE_USER: $ORACLE_USER" >> $RMAN_LOG_FILE
echo "ORACLE_HOME: $ORACLE_HOME" >> $RMAN_LOG_FILE
# ---------------------------------------------------------------------------
# Print out the value of the variables set by bphdb.
# ---------------------------------------------------------------------------
#echo >> $RMAN_LOG_FILE
#echo "NB_ORA_FULL: $NB_ORA_FULL" >> $RMAN_LOG_FILE
#echo "NB_ORA_INCR: $NB_ORA_INCR" >> $RMAN_LOG_FILE
#echo "NB_ORA_CINC: $NB_ORA_CINC" >> $RMAN_LOG_FILE
#echo "NB_ORA_SERV: $NB_ORA_SERV" >> $RMAN_LOG_FILE
#echo "NB_ORA_POLICY: $NB_ORA_POLICY" >> $RMAN_LOG_FILE
# ---------------------------------------------------------------------------
# NOTE: This script assumes that the database is properly opened. If desired,
# this would be the place to verify that.
# ---------------------------------------------------------------------------
echo >> $RMAN_LOG_FILE
# ---------------------------------------------------------------------------
# ---------------------------------------------------------------------------
# Call Recovery Manager to initiate the backup.
# ---------------------------------------------------------------------------
CMD_STR="
ORACLE_HOME=$ORACLE_HOME
export ORACLE_HOME
ORACLE_SID=$ORACLE_SID
export ORACLE_SID
$RMAN nocatalog target sys/admin msglog $RMAN_LOG_FILE append << EOF
RUN {
allocate channel c1 type disk;
allocate channel c2 type disk;
BACKUP FORMAT '/u01/backup/orcl_%U_%T' skip inaccessible filesperset 5 DATABASE TAG orcl_hot_db_bk;
sql 'alter system archive log current';
BACKUP FORMAT '/u01/backup/arch_%U_%T' skip inaccessible filesperset 5 ARCHIVELOG ALL DELETE INPUT;
backup current controlfile tag='bak_ctlfile' format='/u01/backup/ctl_file_%U_%T';
backup spfile tag='spfile' format='/u01/backup/ORCL_spfile_%U_%T';
release channel c2;
release channel c1;
}
report obsolete;
delete noprompt obsolete;
crosscheck backup;
delete noprompt expired backup;
list backup summary;
#EOF
"
# Initiate the command string
if [ "$CUSER" = "root" ]
then
echo "Root Command String: $CMD_STR" >> $RMAN_LOG_FILE
su - $ORACLE_USER -c "$CMD_STR" >> $RMAN_LOG_FILE
RSTAT=$?
else
echo "User Command String: $CMD_STR" >> $RMAN_LOG_FILE
/bin/sh -c "$CMD_STR" >> $RMAN_LOG_FILE
RSTAT=$?
fi
# ---------------------------------------------------------------------------
# Log the completion of this script.
# ---------------------------------------------------------------------------
if [ "$RSTAT" = "0" ]
then
LOGMSG="ended successfully"
else
LOGMSG="ended in error"
fi
echo >> $RMAN_LOG_FILE
echo Script $0 >> $RMAN_LOG_FILE
echo ==== $LOGMSG on `date` ==== >> $RMAN_LOG_FILE
echo >> $RMAN_LOG_FILE
/bin/mailx -s "RMAN Backup SID " [email protected] < $RMAN_LOG_FILE
exit $RSTAT