rman-06747

Backup of the flash recovery area is an important activity because this area contains important
backup information that is critical to the recovery of the database. Oracle has developed special
commands to back up the flash recovery area. This is performed to a tape device so that the
backups to the flash recovery can be recovered if there is a disk failure that supports the flash
recovery area.

RMAN> backup recovery area;

Starting backup at 12-APR-08
specification does not match any archive log in the recovery catalog
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 04/12/2008 09:15:19
RMAN-06747: at least 1 channel of tertiary storage must be allocated to execute this command

RMAN> backup recovery files;

Starting backup at 12-APR-08
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 04/12/2008 09:15:34
RMAN-06747: at least 1 channel of tertiary storage must be allocated to execute this command


[oracle*OCP10G@localhost oracle]$oerr rman 6747
6747, 1, "at least 1 channel of tertiary storage must be allocated to execute this command"
// *Cause: The executed command requires a SBT channel, but no channels of
// type SBT were configured or allocated.
// *Action: ALLOCATE or CONFIGURE a SBT channel.

10g引进了flash recovery area，同时在rman备份中支持对该区域的备份，昨天考试的时候还遇到这个问题，就是在备份闪回恢复区域时，oracle会备份那些文件，而不备份那些文件。这个从来还没有考虑过，当然在考场上也是很紧张的。今天查了很多资料，终于在metalink上找到一段话：

To free space in the FRA we could do take a backup of the Flash Recovery Area using the command BACKUP RECOVERY AREA.This command will take the backup of all the files in the FRA to tape only. After this the space occupied by the files in the FRA will be marked as reclaimable

这段话阐明了两个主要问题：

1、就是对recovery area的备份只能备份到tape上，如果备份到disk上，则会报以下错误：

RMAN>
启动 backup 于 31-10月-07
说明与资料档案库中的任何数据文件副本都不匹配
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: backup 命令 (在 10/31/2007 19:38:48 上) 失败
RMAN-06747: 至少必须分配一个三级存储通道以执行此命令




2、会备份存储在fra中的所有文件。即备份集、镜像备份、自动备份的控制文件和spfile文件、flashback log、归档重做日志等。