Well folks, its that time once again; we've another XenServer build ripe for your inspection, and this one is a critical one for a number of reasons. Today we've released XenServer Creedence beta.2, and this is binary compatible with a Citrix Tech Preview refresh. The build number is 87850 and it presents itself to the outside world as 6.4.95. Over the past few announcements I've hinted at pushing the boundaries of XenServer and wanting the community at large to "have at it", but I've not put out too many details on the overall performance we're seeing internally. The most important attribute of this build is that internally, its going to form part of a series of long term stability tests. Yes folks, we're that confident in what we're seeing and I wanted to thank everyone who has participated in our pre-release activities by sharing a few performance tidbits:
- Creedence can start and run 1000 PV VMs with only 8GB dom0 memory. That's up from the 650 we have in XenServer 6.2.
- Booting 125 Windows 7 VMs on a single host takes only 350 seconds in a bootstorm scenario. That's down from 850 seconds in XenServer 6.2
- Aggregate disk throughput has been measured to improve by as much as 100% when compared to XenServer 6.2
- Aggregate intrahost network throughput has been measured to improve by as much as 200% when compared to XenServer 6.2
- The number of virtual disks per host has been raised by a factor of four when compared to XenServer 6.2
When compared to beta.1, the team has been looking at a number of performance and scalability system aspects, with a primary focus on dom0 idle state behavior at scale. This is a very important aspect of system operation as overall system responsiveness is directly tied to the overhead of managing a large number of VMs. We did see two distinct areas for investigation, and are inviting the community to look into these and provide us with others. Those two areas are:
- When using 40Gb NICs outbound (transmit) performance is below expectations. We have some internal fixes, but are encouraging anyone with such NICs to test and report their findings
- When large numbers of hosts are pooled we're seeing VM start times appear to slow unexpectedly under large pool VM densities.
As always we're actively encouraging you to test the beta and provide your feedback (both positive and negative) in an incident report. You can download beta.2 from here: http://xenserver.org/component/content/article/11-product/142-download-pre-release.html, and enter your feedback at https://bugs.xenserver.org.