Libro sobre Proxmox maestria
Current load versus future growth
Never design a cluster with only the present day in mind; always look into the future, at least the near future. An enterprise cluster must be able to grow with the company and adapt to the increased operations. However, for the most part, plan in such a way that a cluster does not max out in a very short period of time. Both Proxmox and the Ceph cluster have the ability to grow at any time to any size: this provides the ability to simply add new hardware nodes to expand the size of the cluster and increase the resources required by virtual machines.
When installing memory in nodes, never add memory only to run the existing virtual machines, but foresee any future virtual machine migration to any nodes during a node failure. For example, let's say all the six nodes in a Proxmox cluster have 64 GB of memory, and 60 GB is consumed at all times by all the virtual machines. If node 1 fails, you will not be able to migrate all the virtual machines from node 1 to the other five nodes. This is because there will not be enough memory to go around. We could just add another spare node and migrate all the virtual machines, but we have to make sure that there are enough power outlets to even plug in the new node. Usually, 50 percent of the maximum capacity should be free in a cluster environment. This is possible if you have a large budget.
Budgetary concerns always play a role in decision making, no matter what kind of network environment we are dealing with. However, the fact is that a setup can be adaptable to just about any budget with some clever and creative planning. Times too numerous to count, administrators have had to work with a very small IT budget. Hopefully, this chapter will help you find that missing thread to connect a budget with proper hardware components.
Simplicity is often overlooked in a network environment. A lot of times, it just happens naturally. If we are not mindful about simplicity, we can very quickly make a network unnecessarily complex. By mixing hardware RAID with software RAID, putting one RAID within another RAID, or through a multidrive setup to protect the OS, we can quickly make the cluster go out of control. Both Proxmox and Ceph can run on high- grade commodity hardware. For example, just by selecting the desktop-class i7 over the server-class Xeon, we can slash the cost by 50 percent while providing a very stable and simple cluster setup, unless the task specifically calls for multi-Xeon setup.