: Ensure storage array firmware and ESXi drivers are up to date and compatible.
The VMkernel logs will fill with ATS Miscompare or Status: Op: 0x89 messages. How to Troubleshoot and Fix : Ensure storage array firmware and ESXi drivers
"Atomic test and set of disk block returned false for equality" is a low-level status message typically found in VMware ESXi VMkernel logs It indicates a failure in the Atomic Test and Set (ATS) , which is part of the vStorage APIs for Array Integration (VAAI) Core Concept: What is ATS? Because the comparison failed, the storage array refuses
Because the comparison failed, the storage array refuses to perform the "Set" (write) operation. This is a safety mechanism to prevent data corruption when multiple hosts are competing for the same resource. Common Causes technical breakdown Caution: Only clear reservations if you
The lights in the room didn't just turn off; they ceased to have ever existed. technical breakdown
Caution: Only clear reservations if you are certain no active node holds them.