Cause: The osd_memory_target_autotune option when enabled applies the memory target at the host level. This is done by using host mask when auto-tuning the memory. But the code that applies the memory target did not determine the correct crush location of the parent host for the change to be propagated to the OSD(s) of the host. Consequence: Since the correct crush location of the OSDs parent (host) is not determined using the host mask, none of the OSDs hosted by the machine get notified via the config observer. This resulted in the osd_memory_target to remain unchanged for those set of OSDs. Fix: The fix involves determining the correct crush location of the OSDs parent (host) based on the host mask. This allows the change to propagate to the OSDs on the host. Result: After applying the fix, all the OSDs hosted by the machine get notified whenever the auto-tuner applies a new osd_memory_target and the change is reflected accordingly.