To carry on where we were last week, lets start looking at the numbers. Once we have a list of the applications, then we need to crunch some numbers. If you have 50 hosts, and out of those 50 hosts each one has 25 guest VMs then you would have 1250 VMs you need to migrate. But what if you only have a few VMs, and everything else are all physical machines? Then you need to add an additional step for converting them from P2V (Physical to Virtual) or P2V2C (Physical to Virtual to Cloud). Not hard to do, but it takes time and allot of after hours work.
If we now take the 1250 VMs that we mentioned before, and now applied how many separate applications we have over the top of it, it should give us a number we can look at more closely. If the customer has 400 applications, we subtract it from the 1250 VMs that would leave us with 850 VMs. This number says every application needs its own VM, which we know most of the time it is not true. Also, the new number doesn’t take into consideration clustered, print servers, fault tolerant units or server farms. So, out of those 850 VMs, some will still need to be around.
We crunch the numbers again. Everything you move to a hosted cloud, you pay for. Period. Whether it is CPU, RAM, Disk, Bandwidth you will pay something, somehow for it. And, if you use additional services that the cloud provider can offer, such as Databases Management, Backups, Managed Services, your ticket will grow per VM instance that you have in the cloud. So, we need to make sure that applications can coexist on the same VMs to save money. The only way to tell that is to monitor the application’s usage of resources and see if another application or a few can buddy up with it on the same VM.
Now, once we get to this point I ask them “Why?” Why do they want to move to the cloud? What do they expect to get out of it? Do you have a test environment already that you have been learning cloud management on? Do you own licenses for locally installed software or do you plan on using an open source solution? Does the term “all or nothing” really work for the cloud? Do you have certified personnel on staff that can use the selected software or environments to benefit your company and make the migration successful?
I will get into the weeds of each step, why we need them, and caveats if we forget something or take it for granted. We need to look at the roles and responsibility matrix for each organization, and who does what when and where.
Cloud is simple, robust and easy to use if you plan accordingly. Just because you are being circled by hungry sharks, doesn’t mean they will bite!