The front-facing API can be improved to support lots of requests when the platform is huge with lots of virtual resources. The current design requires to extraction of lots of data so it leads to some latencies for some requests.

Adding more customization layers to Sunstone can also speed up the way we can expose it to our customers.

Even if some huge improvement has been made, we cannot still open it to be used directly and autonomously by our customers. 

We need to dig more into the last releases to see what can be improved.

OpenNebula's templates are weak, and it could do something to make template creation a lot easier to use. The solution has a template for every single VM you create, which is not clever. You should be able to use a template for many different virtual machines.

There are no payment gateways in OpenNebula.

I've found OpenNebula upgrades to be more complex than those of some of the competitors and the support to be mediocre.  

I would also like to see more and better ancillary tools related to OpenNebula, for example, more robust tools for backups, user support, etc.  

The support knows their software stack reasonably well. However, OpenNebula depends on so many open-source projects that they lack expertise.  

As with all enterprise software licensing, the pricing is not intuitive and must be negotiated; grandfathered contracts are better than anything offered today.  

I would like to see OpenNebula add more integration with REST API. XML-RPC API is good, but it becomes a pain to form a resting output. The pathway and prediction and all those things can be tricky.

It should have a simple REST API like most other tools. It's the industry standard format. An XML-RPC API gives you an XML document that you have to convert and then do something with that. REST API endpoint provides outputs in a JSON document. I would also like to see support for user data or heat templates, which OpenStack offers, but OpenNebula doesn't have this yet. 

The structure of the documentation is very messy. You can't find anything you want. When you search for features you are faced with many different topics and they don't have any connection to each other.

Compared to the documentation for VMware, it is really simple and messy. You find many topics that are not related to each other and you have to read all of the documents from beginning to end if you want to know how to set something up. For example, if you want to set up Kubernetes then you should be able to search for the top and learn how to do it. However, with OpenNebula, it is too difficult to do that.

They have been saying for the past two and a half years that they would develop a feature to hot-add RAM and CPU, but it does not work. They keep postponing it to the next version and we are impatiently waiting for it. When the ability to hot-add or remove RAM and CPU inside the virtual machine is working, it will be very good.

The community has some weaknesses. For example, the answers are sometimes very short and contain no detail, like "Working on it", without answering with specifics.

Another weakness is that you have to develop a third-party portal from outside and connect using the NSX API directly from it.

Hosting platforms are limited so the deployment process needs improvement. There are some kernels that limit hosting or cause issues with the CLI which only works on the server where it is installed. To solve this issue, we use a virtual box with user centers that run the solution for particular machines. 

Upgrades sometimes have compatibility issues that require changes on our end and this should be improved. For example, a 6.4 or 7.0 release should be downward compatible with the 6.0 version.  

The multiple stacks are built on the Python side but need a .NET extension. 

The CLI is on Ruby on rails so can be complex. 

An installation video that walks through all setup steps would be useful. 

The UI, monitoring, and alerting could benefit from further improvements.    

The marketplace feature that they had wasn't really up to the mark as they published it. That is something that they could improve.

They need to improve their customer support as well.

The storage feature that they have is a bit confusing. At first glance, it would all look okay. However, they need to be very specific about how their storage is occupied at the OpenNebula level. That would give a pretty clear idea to the end user on how to deal with it and how to plan ahead. 

An area for improvement in OpenNebula is the number of features it has. The solution doesn't have that many cloud features compared to other solutions. You'd say, "Okay, simplicity over a rich feature list?" Some say, "No, I need a big machine or a cloud interface for my customers to manage resources. I don't have to go and do it for them." Some people do it that way, and it works, but I'd like to improve the limited features in OpenNebula.

Template management also needs improvement in OpenNebula because it's inferior right now. I speak from experience because I've worked with multiple private cloud solutions, and most of those solutions have template management and networking all figured out, making it easier for new users to start immediately.

With OpenNebula, you'd need a networking expert to have a full-fledged cloud. The OpenNebula team assumes that you know this. Still, most developers don't because they don't do networking, so you'll end up with a half-configured cloud or an OpenNebula that needs many inner workings to run. It would be great to have an OpenNebula assistant to guide users in configuring the servers. Otherwise, the solution may need to be rebuilt.

In the next release of OpenNebula, I'd like it to have an automatic network provisioning feature.

The protocol for clusterization is rough and doesn't work well. We stopped using that feature because we had problems. It's not always easy to find answers on the forums if you're using the open source product. 

Backup features are only available in the enterprise edition. The community version lacks a good solution for making backups. 

It's very tough, depending on the requirements. There are small things that are hard. For example, making sure that it is going to be installable on public clouds so that you can have different drones on public clouds and different public clouds, and making sure that everything is going to work seamlessly whether on-premises or on the cloud. Right now, on public clouds, you cannot actually install OpenNebula. 

They should add more features like object storage. They should improve some management feature for the storage, for example, they should put third party staff. The integration features should also be improved but I believe they are working on it. 

They should add HDM and HDS features. 

With a detailed billing module, this can be used as a complete public cloud implementation, and we are waiting to see that module from OpenNebula.

Most of the competitors are offering some sort of billing software to transform their installation to work as a small-sized public cloud, but those offerings from OpenNebula are still missing.

With the addition of this module, it will bring completeness to the overall offerings. We hope that OpenNebula listens to this and bring quickly the module.