Disaster recovery as a service (DRaaS) is now a mainstream offering that includes cloud service benefits. According Gartner’s Magic Quadrant for Disaster Recovery as a Service, from 2016 through 2020, the use of either DRaaS or Infrastructure as a Service (IaaS) to support the failover of production applications will grow by more than 200 percent. Still a lot of businesses have physiologic obstacles when they try to give up the “storage disaster recovery” by replicating to the cloud. Although DRaaS is here to stay and to take the lead (no doubt about it) and is currently offered by 250 providers, it’s important to understand what’s needed to know when choosing between disaster recovery service providers. In this post, we will cover the differences between real DRaaS versus storage disaster recovery. We are basing our conclusions on interviews we made with 874 of our customers. Our number one question to examine this comparison is: Is software replication better than storage-based replication for offsite disaster recovery? The answer is yes. Storage disaster recovery lacks DR capabilities. Here you got a list of demands you should give to the disaster recovery service providers:
- Database consistency. Consistency in database systems refers to the requirement that any given database transaction must change affected data only in allowed ways. Any data written to the database must be valid according to all defined rules, including constraints, cascades, triggers, and any combination thereof. This does not guarantee correctness of the transaction in all ways the application programmer might have wanted (that is the responsibility of application-level code), but merely that any programming errors cannot result in the violation of any defined rules. This ability can’t be delivered with storage-based replication, only DRaaS-based inbound software. Consistency is one of the four guarantees that define ACID transactions, however, significant ambiguity exists about the nature of this guarantee. It is defined variously as: * The guarantee that any transactions started in the future necessarily see the effects of other transactions committed in the past. * The guarantee that database constraints are not violated, particularly once a transaction commits. * The guarantee that operations in transactions are performed accurately, correctly, and with validity, with respect to application semantics. As these various definitions are not mutually exclusive, it is not possible to design a system that guarantees “consistency” in every sense of the word, as most relational database management systems in common use today arguably do. Think of exchange server disaster recovery or sql server disaster recovery. Most databases like SQL or Oracle are a scalable, reliable, flexible, and high-performance relational database management system for server-based systems. Your product needs to provides real-time enterprise data protection and replication.
- The freedom to change. During the past year, DRaaS has undergone significant changes. Disaster Recovery Providers monthly service pricing and cloud usage policies have become increasingly fragmented as a direct result of increased IaaS pricing competition. And the more flexible cloud usage policies from hyper-scale cloud providers such as Amazon, Microsoft, and Google. You need to have the freedom to change your home target site, to work with different vendors, to choose a better new provider (for DRaaS), and to migrate your production site to the cloud.
- Disaster recovery testing. Disaster recovery solutions do not work. The primary reason for testing is to identify deficiencies in DR plans. Period tests present opportunities to fix problems before a disaster happens. For these reasons, testing should be done on monthly basis.
- Migrate to the cloud. As part of the cloud buzz, there is a growth in business moving their production site to the cloud. You must have the choice to use this ability (or not). Choosing storage doesn’t allow you to get it in the future.
- Storage providers are clearly focused on box moving. Good DRaaS providers with well-managed customer care programs continue to have high overall customer satisfaction ratings from their reference customers. DRaaS based on software replication offers a very high-touch approach to service delivery, especially with respect to recovery run book development and facilitated exercising. This method also received very high reference customer ratings in relation to the quality of technical support delivered.
- Resilient. Although you chose and love your storage vendor, you should not depend on him in the target. You must have the ability to recover from storage crash. Your DR site should be using different dependencies from your production so that in a real disaster case you will have the ability to continue working without any vendor dependency.
- Physical servers. Modern data centers employ a combination of physical, virtual, private cloud, and public cloud platforms. DRaaS needs to provides technologies that work within and across these diverse computing platforms to provide protection throughout your data center. Whether replicating entire virtual machines between virtual hosts or replicating applications between physical and cloud environments, DRaaS should delivers leading-edge technologies that move data efficiently and keep users online with the least disruption, while eliminating the barriers between physical, virtual, and cloud platforms. Modern data centers are intricate for many reasons. Storage base replication specializing in a single virtualization platform or providing a one-size-fits-all approach to data and application availability. In contrast, software base replication provides different technologies that work together across a complex data center to bring all of your protection under the umbrella of a single provider and a single management interface. Whether your critical data and applications reside on virtual, physical or cloud servers, you should use the most trusted solutions in the industry for keeping users online and information and tools always available. Gartner says until 2020 20% of the servers will still be physical. You need a DRaaS solution that can protect physical environments. The provider should allow you to protect your data and provides fault tolerance as well as immediate recovery from a system outage through the use of a unified console. To offer continuous data replication over any distance, helping to ensure that you always have access to a current copy of your data, applications, and operating system. IT environments are now more complex than ever, with a mix of applications, storage, hardware platforms, and operating systems. Because real DRaaS based on application it application and hardware independent, you benefit from being able to deploy a single solution that delivers replication and high availability for all major Windows and Linux versions running on physical, virtual and cloud-based servers. Market forces demand 24 x 7 availability for your systems, applications and data. They offer the flexibility to replicate data for key applications (i.e. SQL Server), files, or entire physical or virtual machines across your data center as needed to ensure your business keeps running.
- Don’t change the production site configuration. The goal of DR is to maintain the possibility to continue working as usual when any scenario happens. It doesn’t mean an IT project for your production environment. Many vendors and integrators explain the concept that includes the need to change your storage or servers, or saying it’s a great chance to upgrade it. This is totally wrong due to a few issues:
- You need a bigger budget – source and target, while only target is needed for DR.
- The use of storage and your requirements of it is very different from your objectives from the DR.
- This will commit you for the next five years’ source and target.
- You are putting your source site at risk by trying to change it. DR implementation has requirements and a learning period. You don’t need to handle the source site in parallel. So, the first conclusion must be that you shouldn’t involve the DR project in your current infrastructure future changes. Of course, from the vendor’s marketing point of view, the message objective is to increase their sales by promoting two sides of new storage and servers. But for your DR goal, their promotion is irrelevant.