UPDATE: according to a post on Cormac Hogan blog this issue is not limited to version 6.0.6. All firmware versions 5 and 6 can have this issue.
VMware released a knowledgebase article on a serious issue. Customers are advised to upgrade to firmware v6.0.6-H2 as soon as possible.
When using Dell EqualLogic Storage arrays, particularly when running PS Series firmware v6.0.6 within your ESXi/ESX environment, you may experience one or more of these symptoms:
- Unable to power on virtual machines.
- Virtual machines report as Invalid in the vCenter Server inventory.
- Virtual machine files appear to be locked even though the affected virtual machine is powered off.
- VMFS volume may be inaccessible.
- Messages in the vmkernel log or vmkwarning log files indicate METADATA corruption or Lock Corruption.
- Attempting to migrate a virtual machine using vMotion fails with the error:
The operation is not allowed in the current state of the host
- Hard disk failure in the array
- Controller failure in the array
- Unexpected power outage
- Network connectivity issues
More information here.