4.2. Application Restrictions

There are aspects of virtualization which make it unsuitable for certain types of applications.

Applications with high I/O throughput requirements should use the paravirtualized drivers for fully-virtualized guests. Without the paravirtualized drivers certain applications may be unpredictable under heavy I/O loads.

The following applications should be avoided due to high I/O requirements:

You should carefully evaluate applications and tools that heavily utilize I/O or those that require real-time performance. Consider the paravirtualized drivers or PCI device assignment for increased I/O performance. Refer to Chapter 10, KVM Paravirtualized (virtio) Drivers for more information on the paravirtualized drivers for fully virtualized guests. Refer to Chapter 12, PCI Device Assignment for more information on PCI device assignment.

Applications suffer a small performance loss from running in virtualized environments. The performance benefits of virtualization through consolidating to newer and faster hardware should be evaluated against the potential application performance issues associated with using virtualization.