Solution providers using VMware vSphere 5 to provide applications in the cloud can see sluggish performance as
customer demand increases. These five vSphere performance tips will speed up your system, providing customers with faster access to the applications.
1. Manage the number of VMs per host
Especially in fast-growing infrastructures, you easily risk running too many virtual machines (VMs) per host. While techniques such as dynamic resource allocation make it easy to run many VMs on a host, these techniques only work if the load per VM is low. If the per-VM load is too high, you risk overpopulating hosts with VMs that need too many resources, which can hurt vSphere performance.
2. Choose the best guest operating system for vSphere performance
You can install pretty much any operating system as a guest in vSphere. The first priority should always be the best OS for the application, but it makes sense to choose the operating system that is also best for vSphere performance. You can always improve performance by installing the VMware drivers for I/O hardware in the VM, but these don’t change the kernel. To really get the best out of the VM, select an operating system that has been modified for optimal performance in VMware infrastructures, such as SUSE Linux Enterprise Server.
3. Design networking for vSphere performance
A virtual infrastructure that needs the best possible performance also needs a carefully designed virtual network. That means you are probably better off with a design where VMs don’t need to share the network adapters, but instead have dedicated network adapters available. Only in infrastructures where the highest possible network performance is required does it makes sense to dedicate a complete network card to a VM. But it can make sense to create different virtual networks to separate bandwidth usage.
4. Use the VMware Paravirtual SCSI disk driver
When creating a VM, the default is the LSI Logic SAS SCSI controller, which is the safest choice for use on any operating system. But for optimized vSphere performance, the VMware Paravirtual SCSI driver gives better I/O throughput and lower CPU load on the host OS at the same time. This driver is not optimized for all operating systems, whichs is why selecting the right operating system really matters.
5. Discard unused VMs regularly
There’s a major benefit in using physical hardware for every server you need to install: You’ll only install a server if you really need to. Virtual infrastructures are often are polluted with VMs that have been created for several different reasons, such as test environments, temporary production servers, end-of-life servers and more. Keep track of all of these, and at least once a year, try to analyze all of these servers and see if you really still need them.
Optimizing vSphere performance doesn’t have to be hard. Applying these five techniques is likely to bring you a significant performance improvement, which means more satisfied customers for less hardware cost.
About the author:
Sander van Vugt is an author and independent technical trainer, specializing in Linux since 1994. Van Vugt is also a technical consultant for high-availability (HA) clustering and performance optimization, as well as an expert on SLED 10 administration.