A VMWare Enterprise licensed solution consisting of a number of VMWare hosts, shared storage, plus the VSphere management application is a complex product. Obtaining maximum performance means being able to tune a number of different sub-systems, and to get the various sub-systems working together efficiently.
One of the key sub-systems many people over-look is the network. It appears as though many people think that simply plugging gear into a series of gigibit ethernet ports is all that is necessary for inter-connecting the various VMWare solution components. That may be true for a basic level of functionality, but not for optimal performance.
VMWare has a capability called vMotion. This allows guest operating systems to be migrated live from one host to another. This requires synchronization of sessions between hosting physical servers, which relies on an efficient network connection.
vStorage is a function, very similar in capability to vMotion. In this case it is used to migrate file sets between VMWare DataStores in a live scenario. This requires coordination between shared storage devices, between hosts, and between the host and shared storage devices. If iSCSI is used for accessing shared storage, the network beocmes a doubly critical component of this migration and synchronization.
Here are some ideas for improving the performance of a VMWare solution at the network level. Continue reading "Tuning VMWare Network Performance" »