What should a business take into account when choosing between an internal or external DR site as a backup? What are the pros and cons of each?
In my experience, the two major factors to consider are:
1 - Capital vs Operating budget
2 - Internal staffing
- you have a lot more control over the infrastructure and how you use it.
- Operating expenses are generally lower than external and only moderately higher than not having a DR site. Maintaining two sites does not double your budget, and doesn't rquire double the staff, depending on how you use the DR site.
- You can use the DR site for testing and development, within reason, without compromising your recovery capabilities. We found that many vendors won't charge a full license for DR and testing.
- Capital expenses are a lot higher - you now have two sites to maintain and keep in synch. The biggest trap is to skimp on upgrading your DR site and then finding out some back level piece of hardware stops a major application from running.
- you have a lot more control over how you use the DR resources. This is both a pro and a con. One organization I worked for hurt themselves because they (we) felt we needed to use this equipment that was "just sitting there" sucking up money, so they found uses for it that ended up causing conflicts when needed for DR. Fortunately, we discovered this during testing and scaled back on how we used the site.
- Should be almost no CapEx. The vendor should be responsible for maintaining the infrastructure, but you need to factor that into the contract and your primary site refresh cycle. Too often and the vendor will expect you to pay extra and too long, you will risk getting out of synch.
- Don't need the staffing for two sites. While not usually doubled for Internal, you should be able to fully run the external DR with the same staff.
- Higher Operating Expenses. Can be even higher than factoring in CapEx for Internal, but shouldn't be. Of course, when the disaster hits, expenses will increase, plus you are dealing with trying to recover from the disaster at you primary site.
- More of a risk than a con, but you can easily forget about the DR site when you upgrade your infrastructure and/or apps and don't keep the DR contract up-to-date.
There are more on both sides, but in the interest of time and space, I will leave it at these.
I hope this helps.
The DR hosts the business applications in another site in case of disaster. There are several key factors to take in account in choosing between internal and external DR. First data security, hosting DR external can make the data breachable while internal is more secure. Second managment headache hosting internal can be headache for your adminstration team while external can be easier to manage. Finally cost hosting internal has high CAPEX while external have high OPEX.
I think the most important things a business should consider first is the importance of the system in question. If it is mission critical then consider an offsite DR location. Money would need to be spent on the application performing the backup and the bandwidth to the DR site considering it should be able to run the system. If the system in question is not mission critical then a local backup would be more cost effective. So the main decision that needs to be made is the criticality of the system to be backed up. Money is, of course, a consideration, but should not be the first consideration. I am able to control out offsite backups as if they were onsite. This is made possible with using our own servers and have a lot of bandwidth. There is a cost factor using your own equipment so that needs to be taken into consideration. There are pros and cons to both but I believe it should start with how important are the things you need to back up as this sets the stage for future decisions.
Choosing an Internal DR site as a backup has three main benefits, which are cost, control and communication Quality of Service (QoS). By placing the DR site internally, you'll have full control of its operation. In addition, the communication infrastructure between production and DR site is typically done through robust LAN networks, which offer very high QoS. Since all infrastructure reside internally, cost is typically reasonably under control. The disadvantages of hosting the DR site internally, is that this setup mainly protects you against human and infrastructure errors. It does not offer protection against "force majeure" events such as power outages, fires, storms, etc. Hosting the DR site externally also protects you against human and infrastructure errors, plus you have the added advantage of geographical redundancy, which adds additional protection against major calamities at the home site. Of course hosting the DR externally has its disadvantages, which are mainly related to the added costs for implementing the external communication links and the hosting of the DR infrastructure in a remote site. Further more you may experience a decrease in control and communication QoS that comes with hosting the DR site externally. At the end of the day it boils down to: "How critical is my data and how much can I afford to protect it."