RAC RMAN 备份 RMAN-03009 ORA-19504 ORA-27040 RMAN-06012 channel c3 not allocated 错误分析

备份Shell 脚本如下：

########################################################################

## RAC_hot_database_backup.sh ##

## created by Tianlesoftware ##

## 2010-9-21 ##

#########################################################################

#!/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"

# -----------------------------------------------------------------

# 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=orcl1 -- 注意，这里需要连接任意节点就可以

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/oracle msglog $RMAN_LOG_FILE append << EOF

RUN {

allocate channel c1 device type disk connect 'sys/oracle@orcl1';

allocate channel c2 device type disk connect 'sys/oracle@orcl2';

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 c1;

release channel c2;

}

allocate channel for maintenance device type disk connect 'sys/oracle@orcl1';
allocate channel for maintenance device type disk connect 'sys/oracle@orcl2';

report obsolete;

delete noprompt obsolete;

crosscheck backup;

delete noprompt expired backup;

list backup summary;

release channel;

#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=$?

# ---------------------------------------------------------------------------

# Log the completion of this script.

# ---------------------------------------------------------------------------

if [ "$RSTAT" = "0" ]

then

LOGMSG="ended successfully"

else

LOGMSG="ended in error"

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 " tianlesoftware@vip.qq.com < $RMAN_LOG_FILE

exit $RSTAT

但是，运行该备份脚本报错。部分运行日志如下：

…

allocated channel: c1

channel c1: sid=129 instance=orcl1 devtype=DISK

allocated channel: c3

channel c3: sid=131 instance=orcl2 devtype=DISK

Starting backup at 22-SEP-10

channel c1: starting full datafile backupset

channel c1: specifying datafile(s) in backupset

input datafile fno=00001 name=+DATA/orcl/datafile/system.276.730181051

input datafile fno=00004 name=+DATA/orcl/datafile/users.279.730181053

channel c1: starting piece 1 at 22-SEP-10

channel c3: starting full datafile backupset

channel c3: specifying datafile(s) in backupset

input datafile fno=00003 name=+DATA/orcl/datafile/sysaux.277.730181053

input datafile fno=00002 name=+DATA/orcl/datafile/undotbs1.278.730181053

input datafile fno=00005 name=+DATA/orcl/datafile/undotbs2.284.730181347

channel c3: starting piece 1 at 22-SEP-10

RMAN-03009: failure of backup command on c3 channel at 09/22/2010 05:11:10

ORA-19504: failed to create file "/u01/backup/orcl_19logo39_1_1_20100922"

ORA-27040: file create error, unable to create file

Linux Error: 2: No such file or directory

channel c3 disabled, job failed on it will be run on another channel

channel c1: finished piece 1 at 22-SEP-10

piece handle=/u01/backup/orcl_18logo39_1_1_20100922 tag=ORCL_HOT_DB_BK comment=N

ONE

channel c1: backup set complete, elapsed time: 00:01:02

channel c1: starting full datafile backupset

channel c1: specifying datafile(s) in backupset

input datafile fno=00003 name=+DATA/orcl/datafile/sysaux.277.730181053

input datafile fno=00002 name=+DATA/orcl/datafile/undotbs1.278.730181053

input datafile fno=00005 name=+DATA/orcl/datafile/undotbs2.284.730181347

channel c1: starting piece 1 at 22-SEP-10

channel c1: finished piece 1 at 22-SEP-10

piece handle=/u01/backup/orcl_1alogo57_1_1_20100922 tag=ORCL_HOT_DB_BK comment=N

ONE

...

released channel: c1

released channel: c3

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03002: failure of release command at 09/22/2010 05:14:03

RMAN-06012: channel: c3 not allocated

对这个错误的分析过程如下：

1. 日志有c3 通道不能释放的问题。

C3 通道是节点2上的通道，非本地通道。怀疑是这个地方有问题，单独做一个简单的测试：

RMAN> run

{

allocate channel c2 device type disk connect 'sys/oracle@orcl2';

allocate channel c1 device type disk connect 'sys/oracle@orcl1';

delete expired archivelog all;

release channel c1;

release channel c2;

}

2> 3> 4> 5> 6> 7> 8>

allocated channel: c2

channel c2: sid=147 instance=orcl2 devtype=DISK

allocated channel: c1

channel c1: sid=147 instance=orcl1 devtype=DISK

specification does not match any archive log in the recovery catalog

released channel: c1

released channel: c2

这个实验结果证明，报错和通道没有关系。

2. 备份目录的权限问题

allocated channel: c3

channel c3: sid=131 instance=orcl2 devtype=DISK

RMAN-03009: failure of backup command on c3 channel at 09/22/2010 05:11:10

ORA-19504: failed to create file "/u01/backup/orcl_19logo39_1_1_20100922"

ORA-27040: file create error, unable to create file

Linux Error: 2: No such file or directory

channel c3 disabled, job failed on it will be run on another channel

从这里我们可以看出，通道c3 是创建成功了的。但是在通道上c3上不能创建备份集的文件。

因为我实在节点1上做的RMAN 备份。开始以为全部的备份文件都会放在节点1上。所以只在节点1上创建了备份目录。即/u01/backup目录。在节点2上没有创建。问题就出在这个地方。我在就节点2上创建了/u01/backup目录，并赋予了777权限后，备份成功。

最后检查2个备份文件。发现一个问题orcl1通道的备份集文件会存放在节点1的备份目录上（/u01/backup），orcl2通道的备份文件会放在orcl2的备份目录上（/u01/backup）. 因为它的备份文件存放在2个地方，所以恢复的时候会很麻烦。最理解的状态，是所有的备份文件都存放在一个节点，或者共享设备上。

所以，要解决这个有2种方法：

（1）使用NFS。在一个节点上共享备份目录，在另一个节点挂载这个共享。这个所有的文件就会在一个节点上了。

（2）使用存储。

对于NFS mount, 存在着一个比较严重的问题。就是NFS mount在一个节点没有启动的情况下，会极大的影响另一个节点的性能。也就是说，如果RAC一个节点出现故障，导致机器无法正常启动的话，另一个节点不但要承担全部的数据库压力，而且还会受到nfs mount带来的性能负载，基本上导致这个节点无法正常工作。所以从性能上的考虑，使用NFS mount的时候一定要慎重。所以对于RAC 的RMAN 备份文件，最好还是存放在存储上。