Best Time for Cloud Migrations?
An excellent question we are always being asked at Digital Innovations Global, is "when is the best time for cloud migrations?" To determine when the best time to migrate an on-premise server to the cloud, you first need to know how much system resources are being used: memory, CPU and storage I/O activity for each application on each server.
This information will help you to estimate the cloud migration costs for the apps and determine whether they can be shared with other applications, or separated to run on their own virtual, centralised cloud servers for ease of support.
You will also need to review data storage for potential candidate applications and estimate their future costs before deciding if the server is suitable for a cloud migration.
Platform as a Service (PaaS) and Software as a Service (SaaS) can significantly reduce maintenance costs and license fees for an application or platform based software, the best apps for the cloud have limited data usage which does not use large data storage disks.
SaaS, IaaS or PaaS: Selecting the right cloud service model
After analysing your on-premise apps for the cloud, the next important step is to determine what cloud service model will best suit the applications. Many cloud users make the fundamental error in attempting to duplicate the on-premise server architecture in the cloud using Infrastructure as Service (IaaS).
While this approach sometimes works because IaaS is usually the most general and flexible cloud service available, it can most times not be the most cost-effective solution. To really determine if the chosen cloud option is the right solution, you need to ask yourself the following three questions:
- Does the application’s resource usage match with the cloud service pricing model? Any application that accesses a massive SQL database will always incur high storage charges; an application that runs 24/7 will also incur a higher usage charge, therefore look for low resource use applications, especially ones in terms of low data storage.
- Does the cloud vendor allow a business to choose a single cloud provider to support many different application types? Using multiple cloud vendors is very costly; it’s also technically more complex to use multiple hybrid cloud vendors with applications that stay within the on-premise datacentre. You need to find a cloud service that offers the best cost versus support ratio for the largest range of migration candidates.
- Does the cloud vendor replace as much of the on-premise total application platform; hardware, operating system (OS), middleware and application software as possible? The support for user application components is always your responsibility. This support includes software licenses, maintenance and updates, installation and technical support. Higher-layer cloud offerings, such as PaaS and SaaS, displace more cost, which can make them a more valuable option, especially for small or remote businesses with limited technical support resources.
Most companies should always decide first whether an on-premise application can be replaced by SaaS, either one from the same cloud vendor or from one with the same functionality. For example, companies that host customer relationship management (CRM) on independent servers often find that there are other similar SaaS applications available. Higher-layer cloud offerings, such as PaaS and SaaS, displace more cost, which can make them more valuable, particularly for small or remote businesses with limited technical support resources.
Deciding whether to use IaaS or PaaS to support a given on-premise application requires more in-depth analysis. PaaS include operating systems and middleware, so cloud service costs usually include software and support. Savings and support can be major deciding factors, especially if a companies application site license doesn’t cover an apps cloud platform services, therefore not having the right license, may also mean that there is no in-house support.
Migrating to the cloud could also eliminate the need to hire or train on-house support staff. PaaS migrations usually require less hybrid cloud management and they are easier to migrate in-house application services that use the same platform, e.g. on-premise Microsoft IT systems to cloud Microsoft instances. Alternatively, IaaS is a more general and broader approach which is available. If multiple cloud services and providers are not an option, IaaS cloud services are a much better alternative, than PaaS for a very diverse mix of applications.
The cloud will not always be a viable alternative to on-premise consolidation for every application, because most companies will have some in-house IT applications, even when using the cloud. Hybrid public cloud and private datacentres will become vital components, using a single cloud model and provider will definitely ease the transition to hybrid clouds and reduce support costs for applications in the cloud and in the datacentre. Most likely, the simplest cloud model for your company to manage will always be the best.