News

XenServer 6.5 Released

The latest iteration promises dramatic increases in I/O speeds.

• By Keith Ward
• 01/13/2015

The latest version of XenServer was released today, and the new edition is focused mainly on better throughput for stronger I/O performance.

Steve Wilson, vice president of Cloud Engineering at Citrix Systems Inc., announced version 6.5 -- formerly code-named "Creedence" -- in a blog post. Some of the biggest upgrades from version 6.2, the last major release, include the move to 64-bit only architecture; the reintroduction of the Workload Balancing (WLB) appliance; and a 50 percent increase in GPU density.

The big news is the performance improvements. "… we realized that more and more work workloads are now becoming I/O bound.  Thus, the team put a massive effort into improving the data path through the networking and storage systems," Wilson blogged.

He posted numbers to back up that claim. A graphic accompanying the blog showed big gains in aggregate network throughput, from 3 Gb/s to 25 Gb/s, a 700 percent increase. In addition, aggregate storage read throughput went from 2.2 GB/s to 9.9 GB/s, an increase of 350 percent; aggregate storage write throughput saw a 175 percent increase, going from 2.8 GB/s to 7.8 GB/s. The graphic also showed significant speed improvements in booting large numbers of virtual machines (VMs) simultaneously because of new read-caching, and a big reduction in IOPS for the storage array when VMs share a common base image.

Wilson said that the next two XenServer releases are on the horizon, and hinted that something interesting is coming in relation to containerization: "Wait until you see what we're doing with Linux containers!"

The release of XenServer 6.5 came a day after another major Citrix announcement: the company purchased storage virtualization vendor Sanbolic. Virtualization Review columnist Dan Kusnetzky called the acquisition "a great move by Citrix."

XenServer is a free, open source hypervisor that competes with VMware ESXi and Microsoft Hyper-V hypervisors. The latest data from Gartner Inc. shows VMware in the hypervisor lead, with Microsoft second. Citrix is in the quadrant labeled "Niche Players." The report states that XenServer "… is a good product offering at zero cost," but also stated that it "… does not have a strong business model for monetization to cover future investments."