CDP systems usually involve a combination of software and hardware to achieve a
continual transfer of live data to a secondary, sometimes remote, system. If the active
system fails, the CDP-based system will come online in a matter of minutes (sometimes
seconds).
Some CDP systems are hardware-based geolocated SANs, where data is transferred
bit by bit to a remote location. These geolocated SANs are generally composed of expensive
hardware??”a luxury that many of us cannot afford. For those who can afford geolocated
SANs, they should not serve as a replacement for a disaster recovery plan. What
if the network link hiccups and corrupts data? What if the secondary data center is completely
destroyed?
CDP is a great augmentation toward a disaster recovery plan, but it is not sufficient
on its own. Backup/restore planning is still necessary, as is preparing for user or process
disasters, and so on.
Virtualization
A popular practice these days is to consolidate multiple servers onto a more powerful
server using some sort of virtualization software. Virtualization refers to the creation of
separate virtual hardware environments, as shown in Figure 10-11.
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