ASM High redundancy on Quarter rack should be possible
I was reading the whitepaper "Best Practices For Database Consolidation On Exadata Database Machine" http://www.oracle.com/technetwork/database/features/availability/exadata-consolidation-522500.pdf and came across this statement
On page 5
"There is also the option of deploying a smaller pool consisting of an Exadata X2-2 quarter rack for entry-level consolidation of non mission critical systems.This option is discouraged for business critical requirements because it does not fully support ASM high redundancy disk groups (full support for ASM high redundancy disk groups requires a minimum of Exadata X2-2 half rack)."
As a quarter rack has 3 storage cells seems to me that high redundancy should be possible. can some one throw some light on the origin and meaning of this statement ?
Thanks
Robin