Oracle Slow restore performance

[hungng89]

Hi every one

I am troubleshooting Oracle slow restore performance .
Based on the Oracle tuning guide
http://download.oracle.com/docs/cd/B28359_01/backup.111/b28270/rcmtunin.htm#BABBGAHE

If you see data in V$BACKUP_SYNC_IO, then the problem is that you have not enabled asynchronous I/O or you are not using disk I/O slaves.

I wonder how to enable the asynchronous I/O on RMAN ?

Thanks and Best Regards

 

[hogmaster]

This refers to how you mount the filesystems.
Here is ia good link for Solaris OS
http://www.dba-oracle.com/art_orafaq_oracle_direct_io.htm
/good luck