Too Large To Back Up?
If it is possible to back up a large data warehouse at rates of over 11 TB/h for full backup and more than 100 TB/h for incremental backups, maybe not!
The Maximum Availability Architecture (MAA) team has just published a paper covering tape backup of the HP Oracle Database Machine. The conclusion reads:
With the Exadata Storage Server, Oracle provides an architecture that allows customers with large databases to scale their tape backup to any desired peformance level. The number and connectivity of media servers, and the number and speed of tape drives will define the performance limit of backup, not the Database Machine. With two media servers, effective full backup rates from 11.2 TB/hour and effective incremental backup rate of over 104 TB/hour were achieved.
The title of the paper is Tape Backup Performance and Best Practices for Exadata Storage and the HP Oracle Database Machine and the paper can be accessed at the following link:
Tape Backup Performance and Best Practices for Exadata Storage and the HP Oracle Database Machine
Kevin Closson's Blog: Platforms, Databases and Storage 
Though impressive, how fast can you back up to real drives?
“…Instead of using physical tapes, virtual tapes were configured to backup to /dev/null…”
I don’t know…I wasn’t on the project. The point of the paper is to show that as long as you have enough tape device bandwidth, you’ll be able to feed it. At least that is how I interpret the message.