Can you use VPNs to connect? You are going to want to have a secure method to access your servers and data, and most providers offer a virtual private network for this access. For example. Amazon offers its Virtual Private Cloud VPN service. Others only make use of secure HTTP browsers or remote desktop connections or SSH terminal sessions.
Can you segment your network into Virtual LANs easily? This helps for extra security and makes your cloud easier to manage too.
Are there any role-based or granular access controls? With some providers, access is an all-or-nothing proposition. Look for more granularity, where you can limit what ordinary users can do (such as prevent them from stopping or starting a virtual server or making changes to your virtual infrastructure).
Are both Linux and Windows virtual server instances available? While you may not need both kinds of servers, it is nice to be able to bring up what you need down the road. Make sure the exact version of OS is available from your cloud vendor, such as 64-bit or a particular configuration, too.
How do you set up and tear down a virtual machine instance? With many providers, this is done via a Web browser connecting to a portal page. Amazon has its Auto Scale and Elastic Load Balancer features to add or subtract computing resources. Others have simple copy commands, so once you have a "golden" server configured, you can easily make clones.
Some cloud vendors use Ciscos AnyConnect VPN as one of various connection mechanisms to your hosted servers in its cloud.
Some leading vendors to look at in your migration to a hybrid cloud include:
· Skytap.com can set up an entire hosted virtual network of various servers, all via a Web browser.
· Vyatta.com has virtual firewalls and other network infrastructure gear to help secure the hybrid configuration.
· Cloudswitch.com sells a virtual appliance that can be used to move any virtual machine into either Amazon or Terremark's clouds.
· VMware offers a variety of cloud management tools, including vCloud Director, vFabrik that can help create a virtual datacenter and set up pre-configured app services and infrastructure.
· Appistry has its CloudIQ servers that can help scale them up or down.
- Dells Boomi helps integrate a variety of cloud-based servces such as Force.com and Google Apps.