In a blog posted on the VMware Website late Tuesday night, Paul Maritz, president and CEO of VMware, said his company was responsible for a bug in its ESX and ESXi 3.5 Update 2 software.
The bug, which first surfaced on Monday and was widely discussed in an on-line user community, was caused by a coding error that caused the product license for the software to expire at 12:00 am on Monday of this week.
Maritz wrote that the problem also came from patches to the software as well.
The bug caused a number of problems, Maritz wrote, including preventing virtual machines from being turned on, preventing suspended virtual machines from failing to leave the suspended mode, and preventing the migration of virtual machines with the software's VMotion function.
The bug stemmed from the disable date that was included in the beta version of the software, Maritz wrote. VMware ESX 3.5 was released last December, but the beta version expired Aug. 12.
The bug had two causes. The first cause was VMware's not deleting the beta disable date from the final release of the software, and the second was not catching the error during the software quality assurance process, he wrote.
"We are doing everything in our power to make sure this doesn't happen again," he wrote. "VMware prides itself on the quality and reliability of our products, and this incident has prompted a thorough self-examination of how we create and deliver products to our customers. We have kicked off a comprehensive, in-depth review of our QA and release processes, and will quickly make the needed changes. I want to apologize for the disruption and difficulty this issue may have caused to our customers and our partners. Your confidence in VMware is extremely important to us, and we are committed to restoring that confidence fully and quickly."