Due to some incomplete patches in its ESX and ESXi 3.5 products, VMware is dealing with a series of failures when attempting to power a virtual machine.

The problems were first reported around August 12 and are linked to the Update 2 patch released by the company for the ESX and ESXi hypervisor products. According to an e-mail sent by VMware’s engineers to all the customers, the problem appears to be "caused by a build timeout that was mistakenly left enabled for the release build."

The company’s president and CEO, Mr. Paul Maritz released a letter online explaining that when a server’s time clock hits 12:00 AM on August 12, the released code causes the product license to expire, which leads to the impossibility of turning on the powered off virtual machines; the suspended machines cannot leave their suspend mode and they cannot be migrated using VMotion.

Mr. Maritz assured its customers that all their efforts are focused on making sure that this problem will no longer be an issue and that currently, an in-depth review will verify all areas of the system in order to determine which aspects demand a change. "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."

The ended the letter by apologizing for any sort of disruption or difficulty encountered by the company’s clients and expressed his firm belief that very soon their confidence in VMware will be completely restored.