we have a rman backup for 500 GB 9.2 RAC on RHEL3 (3 LTO II drives) that takes 3 hours to complete, but kills the node it runs on. io wait % goes to 60%, cpu is low. the server is pretty much unresponsive until it completes. We allocate 4 channels and are not using the large_pool or tape slaves. We tried the same thing but used Disk (seperate LUN from the database) and the server crashed. ----- Original Message ----- From: Li Li To: Oracle-L@xxxxxxxxxxxxx Sent: Thursday, March 09, 2006 10:42 AM Subject: RMAN impact Hi, all, I just started to look into RMAN backup and recovery and have a question: for example, it takes 2 hours for RMAN to backup the database, how much impact will RMAN have on the database during this 2 hours? Will user be able to access the database during this 2 hours? Any comments would be greatly appreciated!! Regards, -Li