RMAN Restore Database Slow / How To Improve RMAN Restore Performance [ID 467694.1]

最新推荐文章于 2021-04-03 06:04:30 发布

最新推荐文章于 2021-04-03 06:04:30 发布 · 115 阅读

文章标签：

本文详细介绍了在使用RMAN从磁带恢复数据库时遇到性能问题时的排查和优化方法，包括配置合适的通道数量、禁用并行介质恢复、调整大池大小和启用备份磁盘IO从属等步骤，从而显著减少恢复时间。

RMAN Restore Database Slow / How To Improve RMAN Restore Performance [ID 467694.1]

	Modified10-JUN-2010TypeHOWTOStatusMODERATED

In this Document
Goal
Solution

Platforms: 1-914CU;

This document is being delivered to you via Oracle Support's Rapid Visibility (RaV) process and therefore has not been subject to an independent technical review.

Applies to:

Oracle Server - Enterprise Edition - Version: 10.1.0.2 to 10.2.0.4 - Release: 10.1 to 10.2
Information in this document applies to any platform.

Goal

RMAN Restore databaseis slow. Backup to tape takes 13 hours and the restore takes over 26hrs.

Solution

Things to check/configure when RMAN restore from tape is slow :

+ The number of channels to be allocated should be equal to the number of physical tape drives.

+ Set parallelmediarestore off and run the restore :

Example :
RMAN> SET PARALLELMEDIARESTORE OFF;
RMAN> RUN {
allocate channel to tape ...
.
.
RESTORE DATABASE;
RECOVER DATABASE;
}

+ If large pool is not configured then configure the large pool size and enable the backup_tape_io_slaves :
LARGE_POOL_SIZE = 100 m
BACKUP_TAPE_IO_SLAVES = true

By setting the above parameters the restore time reduced from 26 hours to 13 hours.