Migrating SaaS to Cloud: How to do it without disruption

By George Williams
12 Min Read
Migrating SaaS to Cloud: How to do it without disruption 1

SaaS applications work nicely on local appliances (on-premises). However, if you’re running your SaaS on legacy hardware, you’re bound to run into a couple of challenges. And since you’re keeping it to your on-premises infrastructure, you can’t tap into the features or capabilities of cloud computing. That’s a big disadvantage. So, your go to solution? Migrate SaaS to cloud. Easier said than done though, isn’t it?


In this blog post, I take a closer look at:

  • Three reasons why you might want to migrate your SaaS to the cloud
  • Three challenges when migrating your SaaS to the cloud
  • Three ways to migrate your SaaS to the cloud

Yes, we’re keeping it brief by sticking it to the rule of three.

Three reasons to migrate your SaaS to the Cloud

#1 – Overcome legacy infrastructure limitations

One of the most common reasons why organizations move their SaaS workloads to the cloud is legacy infrastructure limitations. These include challenges such as:

  • Limited scalability: The infrastructure needs forklift upgrades. That’s a disruptive, expensive, and inefficient process.
  • End of life equipment: The infrastructure has lived its life. It has been a satisfying experience but now it’s end of life equipment. That means that the warranty is over and any part or parts may fail at any time. In other words, it’s simply riskier to run critical workloads on this equipment.
  • Management complexity: Most on-premises infrastructures require onsite IT staff. The larger the system, the more difficult it is to manage different metrics and features. It consumes time, budget, and as time goes by, productivity too.
  • Compatibility issues: Let’s not forget compatibility problems. Some applications or databases require specific processors or system memory. Unless the organization prepared in advance, that means more forklift upgrades or looking for alternative software; either way it’s not a good experience.

#2 – Data availability

In order to ensure high availability for critical workloads, you have to resort to expensive setups such as replication-based twin cluster nodes, RAID configuration, etc.

Even with the expensive solutions, it’s relatively difficult to ensure high availability for important data. Mostly because of single point-of-failure. Twin clustered nodes are great but they’re expensive. And RAID isn’t bad either but if you don’t replace your hard drives in time, you’ll still end up losing your data.

 In comparison, Cloud Service Providers (CSPs) deploy geo-replication and other similar services to make sure that even if a data center or region goes down, your data remains available.

By putting your data in the cloud, you’re able to leverage the availability measures CSPs have put in place so that they’re in compliance with strict SLAs. And you’re not paying any additional charges to benefit from them.

#3 – On-Premises Hardware

 On-premises hardware is expensive and it continues to consume budget that could be otherwise redirected for core operations. OpEx for an in-house data center includes maintenance cost, power and cooling costs, and the cost of the space reserved for the hardware appliances; not to mention the salaries for dedicated IT staff.

On the other hand, if you decide to put your SaaS in the cloud, you can opt to build a completely hardware less environment. This is particularly good for businesses that don’t have enough space or are looking to save OpEx so that they can focus on core operations.

Now that we know why most organizations migrate their SaaS applications to the cloud, let’s see what kind of challenges they have to overcome to do so.

Three challenges you’ll have to overcome when migrating your SaaS to the cloud

#1 – Disruption

If the SaaS software is a part of your core operations, usually it is, then migration cannot be a disruptive process for you; because that spells downtime and downtime is bad for business.

That implies, you’ll have to find a way to migrate your SaaS applications without disruption (solutions suggested below – see three ways to migrate your SaaS to the cloud).

#2 – Synchronization & Data Integrity

When migrating any workloads, SaaS applications or VMs, it’s a challenge to ensure synchronization. You’d want your applications and staff to continue as though nothing happened or simply start off the next day from where they left off.

However, it’s not easy to do that when migrating from your production environment to cloud-based servers. Secondly, it’s also important to do regular integrity checks.

Integrity checks simply mean that you have to make sure that the data has not been corrupted during the transfer (migration) and is available for use without any problems.

#3 – Cost

Depending on the way it’s done, SaaS migration can be very expensive. And cost considerations are a critical part of any business decision. Verily, moving core SaaS software from on-premises production environment to the cloud is a business decision. Therefore, the consequent cost has to be weighed in.

Best practice is to look for vendors that offer turnkey solutions instead of a component or a couple of components for the migration process.

If IT is not the core of your organization, then it’s ideal to look for vendors who are also offering professional services along with their solution to help with the setup and guide your onsite IT staff so that they can use the software effectively.

We have journeyed across the reasons why you might want to migrate your SaaS application to the cloud and the consequent challenges you’ll have to overcome. Now, let’s discuss the three ways you can migrate your SaaS application to desired clouds.

Three ways to migrate your SaaS application to the cloud

#1 – Use migration applications (vMotion, Azure Migrate, etc.)

If you’re running your SaaS application on VMware, then a good option is the vMotion plugin. It automates VM migration and simplifies migration from one VMware environment to another VMware environment.

If you’re running your SaaS application on an OS installed on a enterprise NAS storage, then things can be comparatively trickier. However, there are software available to help with server migration too. A good example would be Azure Migrate. It can simplify the migration process if you’re looking to migrate your server to Microsoft Azure.

The challenge with these VM migration or server migration applications is that they lead to vendor lock-in. For example, vMotion, despite being quite expensive, will only work for VMware environments. Similarly, Azure migrate is only going to work if you’re looking to migrate your servers to Azure.

Secondly, neither of these are turnkey solutions. They are components. In other words, your staff will have to do most of the heavy lifting.

Comparatively, it’s not a bad idea to look for third party service providers that offer complete data migration services from setup, to transfer, to switch over.

Note: This may or may not be a completely disruption free process. It depends on the chosen vendor. For instance, VMware vMotion promises a disruption free experience.

#2 – Use Data Transfer Devices (DTDs)

The second option are data transfer devices or DTDs.

You might be thinking, “hey wait! How can that be a disruption free option?”

That was true a little while ago but now there are services that leverage DTDs in combination with applications in a way that you don’t feel any disruption at all.

For instance, StoneFly does that with their live VM migration DTDs (for VMware environments only).

How these DTDs work is a combination of replication-based synchronization. First, the major bulk of the data is offloaded to the DTDs, then the DTDs are shipped. The data is transferred to the target location and then the recently written data is synced over the wire. Finally, when everything is synced and ready, the system switches over and completes the migration process.

Note: Again, this option too depends on the chosen vendor. It’s a good idea to clarify during the early stages that you’re looking for a disruption-free process. If the vendor can deliver, they agree to it. If not, then you should look for vendors who can.

#3 – Use replication services over the wire

This solution is only suitable if you don’t have a large bulk of data. For larger data, replication services become expensive, they overload the network, consume compute resources and bandwidth. In other words, everything comes to a grinding halt and this may even take days or weeks depending on the total volume you wish to migrate.

If you don’t have a large chunk of virtual data to move, then this isn’t a bad idea.

Replication, as the term implies, simply copies your data to the target site. Once the replication is completed, you can switch over and then stop the replication process.

It sounds simple and it is, as long as you choose the right vendor and application for the job.


There’s a good chance that the reason why you’re looking to migrate your SaaS application to the cloud is to:

  • Overcome legacy infrastructure limitations like scalability, cost, management complexity, etc.
  • Ensure data availability for your SaaS application
  • Remove the cost & complexity of maintaining on-premises hardware

Here are the challenges you’ll have to overcome to do that:

  • Disruption for your core operations
  • Ensuring synchronization & data integrity
  • Keeping the cost implications in check

Here are three effective ways to do it:

  • Use applications like vMotion or Azure Migrate or third party data migration services that offer completely turnkey solutions
  • Use data transfer devices (DTDs) in conjunction with capable applications
  • Replicate your data over the wire

Which do you think is the best way to migrate your SaaS application to the cloud? Comment down below and share your expertise.

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George Williams is a Technical Content Marketer at StoneFly Inc. StoneFly is a pioneer in the creation, development, and deployment of the iSCSI storage protocol. StoneFly has made iSCSI into a standard that is now used by IT professionals around the world.
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