VMware's chief executive has apologised for the disruption caused by a licensing issue which resulted in the company's latest hypervisors, ESX 3.5 Update 2 and ESXi 3.5 Update 2, not powering on after being turned off.

Paul Maritz
(Credit: VMware)

The bug also prevented virtual machines that had been suspended from leaving suspend mode, and prevented virtual motioning: moving a virtual machine from one host to another.

"I want to apologise for the disruption and difficulty this issue may have caused to our customers and our partners," VMware chief executive Paul Maritz wrote in an open letter this week. "Your confidence in VMware is extremely important to us, and we are committed to restoring that confidence fully and quickly."

Maritz said that the issue was caused by a piece of code in the virtualisation software that was "mistakenly left enabled for the final release of Update 2".

"This piece of code was left over from the pre-release versions of Update 2, and was designed to ensure that customers are running on the supported, generally available version of Update 2," wrote Maritz.

VMware has released an express patch designed to resolve the licensing difficulty, and said it would release a replacement version of Update 2, without the bug, for customers who wanted fresh installs of ESX or ESXi.

Maritz said that VMware's quality-assurance procedures had failed to catch the bug, and that a review of those procedures had been launched.

"I am sure you're wondering how this could happen. We failed in two areas: not disabling the code in the final release of Update 2; and not catching it in our quality-assurance process. We are doing everything in our power to make sure this doesn't happen again."

The bug triggered speculation among VMware customers, in particular on the VMware communities blog, over the availability of a patch. VMware said at the time that VMware was working on a patch as a "top priority".