Atomic Test And Set Of Disk Block Returned False For Equality Link

"Atomic test and set of disk block returned false for equality" is a specialized low-level error message typically found in VMware ESXi environments. It indicates a failure in the Atomic Test and Set (ATS) hardware acceleration primitive, which is part of the vSphere Storage APIs Array Integration (VAAI) Broadcom support portal

ATS is used for locking disk blocks on shared storage without using traditional SCSI reservations. The "returned false for equality" suffix specifically means that when the host tried to acquire a lock by comparing the current metadata to an expected value, the values did not match, or the storage array failed to confirm the change. Broadcom support portal Core Causes High I/O Latency "Atomic test and set of disk block returned

This message typically appears in low-level storage systems, distributed databases, or concurrency control mechanisms (e.g., etcd, Zookeeper, or custom file systems using compare-and-swap operations on raw disk blocks). Broadcom support portal Core Causes High I/O Latency

bool atomic_tas(block_id id, uint64 expected_version, uint64 new_version, void* new_data) lock_page_in_cache(id); uint64 current_version = read_version_from_block(id); if (current_version != expected_version) unlock_page(id); return false; // <-- ERROR: "returned false for equality" This is where the concept of Atomic Test

In the world of distributed computing and high-availability storage, managing shared resources is a constant battle against . When multiple servers (hosts) have physical access to the same storage volume, they must have a way to communicate who "owns" a specific piece of data at any given time. This is where the concept of Atomic Test and Set (ATS) , also known as Hardware Assisted Locking , becomes critical. The Purpose of ATS

This specific error message——is a highly technical diagnostic typically found in low-level systems programming, specifically within storage virtualization or clustered file systems (like VMware’s VMFS) .