Block Returned False For Equality 'link' — Atomic Test And Set Of Disk

The phrase "atomic test and set of disk block returned false for equality" typically points to a low-level synchronization failure within a filesystem or a storage area network (SAN). This error indicates that a system attempted to update a specific block of data but found that the block’s current state did not match the expected "baseline" state.

Step 4: Simulate Test-and-Set Manually

Use sg_compare_and_write (from sg3_utils) to test the atomic operation: The phrase "atomic test and set of disk

Log Events: Frequent LUN reset or ATS failure messages appearing in the vmkernel.log. Potential Resolutions Potential Resolutions Root cause: The power outage caused

Root cause: The power outage caused two nodes to believe they owned the same disk block region (split-brain). The DLM’s internal block version counter had reverted to 0 on one node after unclean shutdown. The phrase "atomic test and set of disk

Example log (from a real cluster):