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

目录(?)[+]

RMAN Restore Database Slow / How To Improve RMAN Restore Performance [ID 467694.1]
	Modified 10-JUN-2010     Type HOWTO     Status MODERATED

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 database is 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.