Symptoms

Metro drop after a device drops not ready on the link.

Cause

This is due to a code issue. Handle Non-Complete Write (HNCW) is being called twice during the same IO. The first time through HNCW it frees the pipeline record and works successfully. The second time it cannot find the pipeline record as the first time through it was freed. This causes the code to then set the write pending mask incorrectly and sets the track invalid. When the SRDF director is generating a write task, it finds the track is invalid. It then checks if Metro is Active-Active and the code falsely believes that the device is not ready and drops Metro.

Resolution

If encountering this issue, contact the Support Center and quote this ID. Workaround: Establish Metro. Permanent Solution: There are two fixes that resolve this issue and both are in 10.2.0.0 (Magnolia) and above: PMOS-61165PMOS-61217

Support Cases