今天早上收邮件，看到师父发的rman恢复失败的邮件。

内容如下：

数据都已经解压完毕。 在/orabak/Oracle_bak 下

但恢复时读取备份片总是报错

channel dev1: reading from backup piece/orabak/oracle_bak/fullrac_EPTDB_820_1_20130802

ORA-19870: error reading backup piece/orabak/oracle_bak/fullrac_EPTDB_821_1_20130802

ORA-19587: error occurred reading 0 bytesat block number 1

ORA-27091: unable to queue I/O

ORA-27067: size of I/O buffer is invalid

Additional information: 2

ORA-19870: error reading backup piece/orabak/oracle_bak/fullrac_EPTDB_820_1_20130802

ORA-19587: error occurred reading 0 bytesat block number 1

ORA-27091: unable to queue I/O

ORA-27067: size of I/O buffer is invalid

Additional information: 2

系统日志中也可以看到

Fri Aug 9 00:30:04 2013

Corrupt block 1 found during reading backuppiece, file=/orabak/oracle_bak/fullrac_EPTDB_820_1_20130802, corr_type=1

Fri Aug 9 00:30:41 2013

Corrupt block 1 found during reading backuppiece, file=/orabak/oracle_bak/fullrac_EPTDB_819_1_20130802, corr_type=1

Fri Aug 9 00:30:41 2013

确认传输过程中没有问题。

似乎在这台机器上，RMAN没有办法正确读取备份片。。。

晕了。

我第一反应是备份集的问题，于是去备份目录下看了下。

-r--r--r--1 oracle oinstall 20611072 Aug 08 16:41 ctl_EPTDB_824_1_20130802

-r--r--r--1 oracle oinstall 21474836480 Aug 08 16:42 fullrac_EPTDB_818_1_20130802

-r--r--r--1 oracle oinstall 21474836480 Aug 08 16:45 fullrac_EPTDB_818_2_20130802

--都是只读权限，我觉得有问题，可想了下，rman备份是读取备份集，不用写应该不造成什么影响吧，但想是这么想，总觉得怪怪的。

于是查了下MOS，果然是权限的问题：

APPLIES TO:

Oracle Database - Enterprise Edition - Version 10.2.0.1 to 10.2.0.4 [Release 10.2]Oracle Database - Enterprise Edition - Version 10.1.0.2 to 10.2.0.1 [Release 10.1 to 10.2]Information in this document applies to any platform.***Checked for relevance on 06-May-2013***

SYMPTOMS

RMAN restore of read only backuppieces fails as follows:

.

ORA-19870: error reading backup piece

/bugmnt/am/ceaixcb5/tar5619852.992/app/oracle/oradata/TARCS/bkup_03hp58dk_1_1

ORA-19587: error occurred reading 0 bytes at block number 1

ORA-27091: unable to queue I/O

ORA-27067: size of I/O buffer is invalid

Additional information: 2

failover to previous backup

.

RMAN-571: ===========================================================

RMAN-569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-571: ===========================================================

RMAN-3002: failure of restore command at 07/26/2006 13:13:17

RMAN-6026: some targets not found - aborting restore

RMAN-6023: no backup or copy of datafile 4 found to restore

CAUSE

The backuppiece is in read only status at the operating system level.

SOLUTION

Make the RMAN backuppiece not only readable but also writable. See Bug 5412531 for other details.

--确实需要写的权限！

REFERENCES

BUG:5412531- RMAN FAILS RESTORING READONLY BACKUPS: ORA-19870 ORA-19587 ORA-27091 ORA-27067

解决：赋予写的权限即可。

经过修改权限后，进行验证就不会报错了。

cd/orabak/oracle_bak

chmod775 *20130802

RMAN>restore controlfile validate;

Startingrestore at 09-AUG-13

usingchannel ORA_DISK_1

channelORA_DISK_1: starting validation of datafile backupset

channelORA_DISK_1: reading from backup piece/orabak/oracle_bak/ctl_EPTDB_824_1_20130802

channelORA_DISK_1: restored backup piece 1

piecehandle=/orabak/oracle_bak/ctl_EPTDB_824_1_20130802 tag=TAG20130802T210600

channelORA_DISK_1: validation complete, elapsed time: 00:00:02

Finishedrestore at 09-AUG-13

之后的恢复也没有问题。

注意：中间恢复失败，或者手工停止后，要将rman相关进程杀干净再重新恢复，否则后面会有问题。说不定在第二次恢复过程中，第一次的进程才停止，然后把相关文件删除，其实删除的是第二次才恢复的文件(因为文件名相同)。

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