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As companies choose to virtualise more of their servers, choosing the right hardware has never been so important. The servers you deploy will impact upon your total cost of ownership, the performance of your business apps and the efficiency of your data centre. By simply spinning up a new VM on existing hardware, your business could save a fortune by choosing the right hardware purchase.

Here are some of our top tips for selecting the best server for virtualisation.

Memory and Server Virtualisation

A long standing myth suggests that we humans only use 10% of their brain power. RAM on the other hand seems to be doing a much better job! Even so, it is commonly acknowledged that memory is often the most limiting factor in the number of virtual machines a server can host. Ensuring an adequate amount of fast RAM plays a huge role in the server’s virtualisation capabilities.

A shortage in either RAM or processing power can directly affect performance, so we would recommend directing your buying efforts on memory capability. Anywhere from 128 GB to 512 GB of low power DDR3 RAM is becoming the industry standard for most servers. High end servers may host up to 1TB of memory.

CPU Options

The faster the CPU, the faster the server’s computing performance. Now with the introduction of multi-core CPUs, it has become much easier and more cost effective to increase the number of CPUs in one server. A handy rule to remember is that four single CPU VMs can be supported per CPU core.
Always aim to have at least one more core than the maximum number of vCPUs that are assigned to a single VM. For example, never buy a two processor dual-core server with a total of four cores and try to run a four vCPU VM on it. The reason being that the CPU scheduler of the hypervisor needs to find 4 free cores simultaneously each time the VM makes a CPU request. If there are only four available cores, the performance will be very slow. Our recommendation would be to use at least quad core CPUs because more cores provide the CPU scheduler with more flexibility to process requests.

Rack Servers

Rack servers act as complete computers providing everything from processors and memory to disk bays and independent I/O slots for expansion. We would advise you make sure you have enough space to include enough physical servers to survive the loss of a single server. One physical host cannot go offline for even 5 minutes to replace a failed DIMM, so it’s best to plan carefully ahead with redundant hardware available.

Create a Scalable Pool of Virtualised Server Resources

Another trend we have noticed is the use of consolidating applications onto server resource pools. These provide exceptional flexibility for optimising resource utilisation. Virtual machines running live applications can easily be moved from one physical server to another with no application downtime. This facilitates very efficient workload balancing, server maintenance and disaster recovery which can deliver sensational improvements for IT departments at a surprisingly low cost. Score!

Storage and Server Virtualisation

When it comes to server architecture, Storage has always played the part of the breadwinner, providing disk space for OS startup, databases and other demanding server applications. Notable benefits of centralised storage include SAN or network boot-ups and data protection storage thus, taking the burden off individual servers. When no data is stored locally, each server can be swapped quickly and easily without needing to reload operating systems or VM images from backups (AKA your worst nightmare). Central storage makes this process much more efficient.
Conclusively, server hardware choices for a virtualised environment boil down to several considerations including available computing resources, resiliency requirements, available budgets and the units physical deployment in the data centre.

For more advice on choosing the right server hardware, or upgrading your existing machines, call Touchpoint on 02 8424 3500 or drop us a line.