Kelem Consulting Limited

Recovery and Availability

This area will cover the subject areas of availability and recovery, critical subjects for all busineses.
We will also discuss Business Continuity which includes but isn't the same as Disaster recovery
Whilst we prepare this area we'd like to repeat an amusing definition of High Availabilty in response to our question concerning the lack of clustering on a critical production system.

Q: Why is the production server not clustered?
A: "We don't support clustered SQL Server."

Q: OK. But your documentation states you have "highly available servers"
A: The Server has two power supplies and we're using a SAN.

Footnote: The "SAN" was actually a 1TB iscsi appliance marketed for small businesses.
Interestingly the "SAN" had a power supply failure, despite having dual power supplies, and corrupted one of the production databases.