We have talked some on who needs cloud and why you need the cloud. Now I wanna talk about what is involved in building a cloud. Cloud computing consists of the layers you see in the image to the left. I wanna focus on the foundation of infrastructure and how you build a proper one. What makes for a solid cloud foundation. We will talk later about processors and memory and how many servers you need to start a cloud off. For now I wanna start with what seems to be the weakest link, storage.
If you spend time researching cloud technologies you will find that the thing people have the most problem with is the IO speeds of the hard drives. This is a big problem as all of your other layers rely on IO. If you have slow speeds then your Platform and Software services will not run as efficiently as possible. So how do you solve the issue of hard drive speeds?
The answer to this can get rather technical. Read and write speeds are ranked normally by RPMs or rotations per minute. Your standard computer runs anywhere from 5400 RPMs to 7200 RPMs. A gamer or a standard server might have a 10,000 RPM hard drive. But to see real speeds over what would be multiple machines you need to go expensive. At a minimum you would be looking at 15,000 RPM specialized hard drives. And even those would not provide the speed we are looking for. So then your really limited and Solid State Drives (SSD) would be your option or is there something better?
Lets start by looking at SSDs. SSD does not run in RPMs as there are no disks to spin. They work in data transfer rates. Your standard SSD will run at something like 250 MBps for reading data, and 180 MBps in writing you data. Part of that limitation is due to the actual controller. Another part is that Operating Systems are still being optimized for Solid State Drives. The big downside is the life of a solid state drive. There performance reduces over time as they have a limited amount of write sequences before they degrade.
There is one other option that is starting to emerge as what will be the future in server storage. Its headed by a group names FusionIO. They are putting SSD storage directly onto cards that are plugged into the server. This seeps up the Read and write speeds and also allows for faster transmissions.
The most viable option to me is the FusionIO system. They see storage as its own virtualized layer which it should be. Allowing for fast but not so affordable storage capacity in the cloud. This is a must for any application and can be a differentiator when deciding between cloud providers.