written by
Ninad Gupte

Why Disaster Recovery is required in Cloud too

AWS Disaster Recovery 5 min read

Is there a need for a Disaster Recovery in the cloud? Isn't AWS cloud safe from malfunctions and disasters? Nothing is safe from the manmade disaster or extreme weather conditions or natural calamities. That is the prime reason for opting for a Disaster Recovery Solution.

The AWS infrastructure build is very robust and many measures are taken to ensure its robustness. There are about 60 availability zones (AZ) across all the 20 regions that are dispersed across the globe. Every region has multiple availability zones (AZ) and each AZ are separate in power supply, and other infrastructure. Disaster can occur at any of the AZ but it is unlikely to occur in all the AZ in a region. However, it may occur by a small chance under extreme natural calamities. Having the right backup solution can save your business from downtime or even total loss of data.

Disaster Recovery based on EBS Snapshots

Interpole's AWS Backup & 1-Click Recovery solution (IBR) offers an EC2 backup and disaster recovery solution based on EBS snapshots. Snapshots are quicker and easier to take without affecting the host. And snapshots are used to recovery rapidly by creating a volume from it and restoring the EC2.

All the EBS snapshots are stored in the S3 which is a separate infrastructure than EC2. Because of this, taking snapshots has become an excellent solution for backup and recovery. Within minutes we can restore the instances in another region or availability zone AZ using snapshots.

EBS snapshots are incremental, meaning when you take a new snapshot only the storage blocks that were changed since the last snapshot are stored. This remains the same for copying snapshots as well so that only the blocks that were changed since the last snapshot will be copied. Even though this is easier to create copies it would become expensive in the long term. So if you implement a backup solution that takes a snapshot every couple of hours, it will not be feasible to copy every time to another region, even if you are willing to pay the costs.

Interpole's AWS Backup & 1-Click Recovery solution (IBR)

With Interpole's AWS Backup & 1-Click Recovery solution (IBR), you have absolute power over all your EC2 Instance backup features. You can define and configure your backup policies for your local backup, detailed scheduling, retention period and more. Additionally, you can recover and restore your instances with the click of a mouse giving you a one-stop solution for backup and recovery across availability zones AZ.

Now if you need a disaster recovery solution that solves the problem across regions for a region-wide outage, you need to scale technical limitations and costs against your business requirement and answer these two questions:
1. What is the Recovery Point Objective (RPO) you need for your local backup? and
2. What is the Recovery Point Objective (RPO) you need for your remote backups?

Recovery point objective (RPO) means, how much data you lose while recovering from the latest backup because the last backup might be a few hours or days old and not up to date. The RPO of daily backup can be up to a day which means that when you recover your data, it will be 1 day old. Is that acceptable for your application? By using IBR, enables you to increase the frequency of backup compared to a daily backup. So why should there be a different RPO for remote regions? This is due to the two reasons that we mentioned earlier limitations and cost, and the fact that a chance for the region-wide outage is much lower than a failure of availability zone AZ.

If your company is completely data-driven and you are willing to prepare for such an event, then IBR is perfect for you as it performs bi-hourly local backups, and copying to a different region will happen on a daily basis. You can balance your business needs against cost and against the probability of an outage by allowing you to configure different frequencies.

Disaster Recovery Recovery in a Remote Region

Along with the backup and copying snapshots you still need to complete recovery using Interpole's AWS Backup & 1-Click Recovery in case of downtime. All you've to do is make sure that IBR server (EC2 Server) will be up and running during such an outage. This can be done by deploying the IBR server away from your other volumes and EC2 instances. Never deploy IBR server in the same availability zone, it is best to deploy in a remote region as the IBR works seamless across regions.

The key challenges when recovering instance at a remote region is that the instance's configuration includes dependencies to other objects like security group, key pairs, kernels, and ramdisks. However, these objects exist at the context of the local region and not at the remote region where you are recovering the instance. Since you are the one defining the key pair and security group, this can be done easily in other regions.

But the challenge is for kernels and ramdisks, you need to search the compatible ones at the remote region. IBR resolves this issue as it finds the right compatible AMI in the remote region that is similar to original AMI. You can use this AMI and it's configuration to launch the recovered instance.

Conclusion

Interpole’s AWS Backup & 1-Click Recovery solution (IBR) offers a broad range of solution for both EC2 backup and disaster recovery. When balancing the business needs and costs for your disaster recovery solution, consider the probability of a region-wide outage and assume you can accept higher recovery point objective than in case of an outage within a region. If your business doesn't allow you for high RPO, then you need to get high availability solution from Interpole.

About InterPole

InterPole was established in 1996 and has been engaged in web hosting, email, and management of IT infrastructure. InterPole pioneered with Virtual Private Servers in 2004 and Cloud Hosting in 2008. Over the years, InterPole has worked with over 6200 mid-sized businesses and startups, and have assisted them in their journey towards the adoption of modern technologies through the Internet. InterPole is a Standard Consulting Partner of Amazon AWS and Microsoft Azure. With this partnership, provides Managed AWS service and maintains a team of engineers who are trained and certified for the specific cloud platforms. These benefits companies in defining their cloud strategy and making a well-planned journey, reliably and cost-effectively.

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