PowerFlex: Acceleration Pool and DAX Devices Statistical Counters Show Zero
Summary: Unlike Storage Pools (SP) and SDS devices, the Acceleration Pool, and Direct Access (DAX) devices do not show any statistical counters, and always shows zero.
Instructions
PowerFlex does not collect performance counters for DAX devices, as those are memory devices. Acceleration devices (aka NVDIMM/DAX devices) are auxiliary devices that Fine Granularity (FG) SPs use to store various internal metadata.
The presentation service (UI) displays data received from the MDM. The MDM manages them in the same code area as regular user-data devices; their --query_properties output includes the same fields as regular devices. However, these devices intentionally contain zero values for all counters because such values are unobtainable and irrelevant.
Acceleration devices do not include user data and do not communicate with any component outside their own SDS host, making monitoring of bandwidth or latency irrelevant. Capacity-wise, PowerFlex does have attributes for regular devices that indicate the acceleration capacity is consumed to support each regular device.
