CISSP 18.3 - Recovery Strategy (Part 2 of 2)

This episode of the ISC2 Certified Information Systems Security Professional (CISSP) exam prep series completes recovery strategy in Domain 7 by finishing the tour of alternate sites and adding database recovery. It covers how the site you choose is a direct trade between money and recovery speed, and how to match the facility to how much downtime and data loss the business can actually survive.

Frequently Asked Questions

What is a hot site, and when is it worth the cost?

A hot site is the opposite of a cold one, a fully equipped backup facility kept in constant working order, with servers and workstations preconfigured, software loaded, and production data replicated continuously or periodically. If replication is live, you switch operations over in moments. The protection is unmatched, but so is the price, because a hot site roughly doubles your spending on hardware, software, and staff, and since it holds copies of your production data, it needs the same security as your primary site.

Where does a warm site fit in between?

A warm site is the sensible middle ground, keeping preconfigured equipment and data circuits ready to run, but unlike a hot site it does not hold a live copy of your data. To bring it online, you transport backup media in and restore your critical data onto the standby servers, which means activation typically takes at least half a day versus the seconds a hot site needs. In exchange, you dodge the heavy telecommunications and staffing costs of real-time mirroring, and if you share one, write a no-lockout clause into the contract.

What are mobile sites and cloud recovery good for?

A mobile site is a self-contained, relocatable unit, often a trailer with its own environmental controls, that you deploy wherever a disaster strikes, and it shines for workgroup recovery, usually set up as a cold or warm site. Cloud recovery has become the go-to for many organizations, storing ready-to-run images with a provider and avoiding most operating costs until a disaster activates the site. If you rely on the cloud this way, negotiate a resource capacity agreement so the provider is contractually bound to supply the capacity you will need.

Why are mutual assistance agreements rarely used?

A mutual assistance agreement is two organizations pledging to shelter each other’s operations in a disaster, sharing facilities without a big capital outlay, which looks wonderfully cheap on paper. In practice three problems sink it: enforcement is hard because an unharmed partner may quietly renege, proximity is a paradox since partners close enough to be useful may be hit by the same disaster, and confidentiality worries make firms reluctant to hand sensitive data to an outside party. They work best between two units of the same company.

How do you keep a database recoverable off-site?

You pick from three techniques, trading cost against how little data you can afford to lose, guided by your recovery point objective. Electronic vaulting ships full database backups to a remote site in bulk, which is simple but recovers only to the last vaulting run. Remote journaling is faster, moving transaction logs frequently, often hourly, so far less is lost. Remote mirroring is the top tier and most expensive, keeping a live server at the backup site that receives every change as it happens, ready to take over instantly.

Reference: This article is based on concepts discussed in CISSP 18.3 - Recovery Strategy (Part 2 of 2).