InformationWeek published a brief but very positive review of XenSource XenEnterprise 3.2:
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After running a battery of tests, we were impressed with the outstanding performance of the slim XenEnterprise hypervisor and XenSource’s paravirtualization approach for hosting Windows Servers–at times running a truly impressive 99.9% of bare-metal CPU performance.
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The Achilles’ heel of Xen, and to some degree all virtualized environments, is the shared disk pool hosting multiple virtual machines.
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The virtualization benefit decreases when systems are short on physical memory and/or are running disk-intensive apps from a shared repository. VMware supports multiple repositories, providing far greater flexibility in host server design and off-box storage options. In contrast, all current XenSource offerings are limited to one storage repository per physical server. This can severely impact performance when two or more resource-intensive app servers start competing for the same disk pool.
In our loaded tests, we found that scores on our PassMark Software PerformanceTest hardware benchmark dropped significantly because of reduced disk performance scores, though the hypervisor does a solid job maintaining and allocating CPU and memory resources across the XenVMs…
Read the whole review at source.