VMS Shadowing vs RAID - your opinions wanted

I'm interested in your opinions on the relative merits of VMS shadowing vs various RAID levels.  

Some of the issues that come quickly to mind are: Cost, Performance, Reliability, Expandability, and Processor loading.  

The application is an audio text (telephone voice response stuff) system using Oracle as the database and a pair of DEC Alpha's running VMS. Call volume is currently about 80,000 per day, expected to double in 18 months. Each call currently involves executing 2 stored procedures that query tables with 250,000 rows, 1 query against a table with 600,000 rows, 2 queries against tables with 1,000 rows, and inserts a row into 3 tables, 2 with 250,000 rows, and 1 with 2,400,000 rows.  

So, let's hear your opinion. (And back it up with logic or facts if you can!)

Steve Edwards       Internet: steve_at_newline.com      Voice: +1-619-723-2727
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