Most of the organization look to the cloud to provide some of the level of contingency against their own systems going down, be it off-site data backup, failover servers for business applications or the use of high-availability servers and software. The business continuity and level of disaster recovery a given organization chooses to put in the places will vary according to its own risk appetite and budget.
With the most basic level of data backup and moving to full business continuity, the following use case scenarios provide some guidance these are the following:
* Simple data backup — the cloud can act as an external storage system where files can be stored so that if there is a problem with on-premise storage, images of specific machines can be restored to a device and individual files can be recovered. It is said that it can be very cost effective, however as with the similar on-premise solutions, there will be a level of down-time while the data is identified and restored to the live environment. Large of the amounts of the data will take a long time to be recovered over the internet which is why Quocirca recommends that data be recovered from the cloud to a local physical device which is then couriered to the customer’s site and then recovered to the target storage system at local area network. The service provider may be able to offer additional archiving services that could work well for the compliance needs.
* Secondary data storage — the cloud can be used as the place where a mirror of existing data is kept. When there is a failure in an on-premise data storage device, systems can failover to use the data being stored in the cloud. Even though this may look as if it provides good levels of business continuity, organization must bear in mind that providing data to on-premise applications from outside the data center may lead to latency issues and that the synchronization of live data may not be as easy as first thought.
* Primary data storage — no data is stored on-premise instead being held directly in the cloud. The latency from the on-premise application to the data will generally make this a non-viable option although this should provide a better data availability due to how the cloud provider architects its storage platform, the latency from the on-premise application to the data will generally make this a non viable option. The data backup and restore is now being carried out at LAN speed.
* Applications and data are held in the cloud with the data back up and restore that is being integrated. The mves of the application and the data closer to each other so that the direct latency is no longer an issue.
* Applications being used as Virtual machines with data being mirrored — In this, by usin applications that have been packed as virtual machine, the failure of a single instance of the application can be rapidly fixed through just spinning up a new instance., this is getting closer to real business continuity.
* Stand-by business continuity — this application virtual machine is permanently spinning, however it is not a part of the live image, the pointers can be moved over to stand-by image in a matter of second, using existing or mirrored data storage.
* Full business continuity — the multiple data storage silos are mirrored on a live basis and multiple application. Virtual machines are maintained, the workloads are balanced between the virtual machines and two level commit is used on the data to ensure that any problem with the data itself is not mirrored across all the data stores.
REFERENCE:
http://www.computing.co.uk/ctg/the-big-picture-blog/2203020/the-cloud-business-continuity-at-affordable-pricing
