Continuity and Disaster Recovery
Continuity. Continuity refers to the ability to get your systems running quickly during an outage. When your server goes down and can’t be brought back up – now what? If you have regular, non-image based backups, here are the steps:
- Find a good backup. This is usually very difficult as few data backups actually work when you need them – especially tape! This could take anywhere between 4-8 hours.
- Get your server hardware fixed. This could take about 4-8 hours if its under warranty, otherwise you are looking at multiple days of downtime.
- Restore your operating system. Expect around 4 hours of downtime.
- Restore your applications. This usually takes about 4 hours as well.
- Restore your data. Expect about 4 hours here as well.
- Total downtime: 30 hours, assuming all went well.
*Also remember that traditional backups are usually done at night so you may have also probably lost a full day of data if not two days of data in addition to the 30 hours you’re down (if all goes well).
What happens if you have server-based image-driven backups?
- Main server is down
- Turn up server image on backup server
- Get back to work with less than 1 hour of data loss
Now lets say your entire local computer room is down:
- Turn up your offsite image-based backups
- Return to work remotely either from home or from the office (if its still workable)
Either of these solutions takes less than 30 minutes to turn up which means less than 1 hour of data loss.
Most disk-based systems today employ what is called an image backup. Basically, instead of a bunch of files, the system backs up the entire server in a container called a virtual machine. This virtual machine, or VM, has all your operating system, application, and data stored in it, and this VM can be ‘turned on’ in the event that your server is down.
This means that when your server is down you wait a few minutes, not many hours, to get back to work. If the local backup system is down as well as the server, the VM can be turned up on the offsite backup system and you can work from there. Really, you are covered and have ‘continuity’ regardless of the type of disaster that happens.