Atomic Test And Set Of Disk Block Returned False For Equality [patched] Jun 2026

Under extreme storage load, the time it takes for an ATS command to travel from the host to the array increases. If the host takes too long to execute the operation, another host may swoop in, modify the metadata first, and complete its write. When the first host's delayed command finally reaches the disk, the on-disk state has changed, causing an instant miscompare. B. Out-of-Sync Firmware and Multipathing Glitches

The Ghost in the Machine: Debugging "Atomic Test-and-Set of Disk Block Returned False for Equality" Under extreme storage load, the time it takes

If a host tries to update a block and the expected state does not match the actual state (i.e., someone else already changed it), the . In simpler terms: "I tried to take ownership, but the block has already changed, so I cannot." 2. Common Scenarios for This Error Common Scenarios for This Error When your system

When your system logs that the operation it means the storage controller checked the disk block, found that its content did not match the "Expected State" provided by the host, and blocked the write to prevent data corruption. Common Root Causes someone else already changed it)

What or filesystem are you running (e.g., VMware ESXi, KVM, OCFS2)? What is the make and model of your storage array ?