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Table of Contents Debugging and Support How do I start an Address Range Scrub (ARS)? How do I record a PBR? What can cause a DCPMM to be marked non-functional? Limitations and Constraints Why is impctl unable to create a fsdax namespaces? Security How do I recover my DCPMM if I have lost my user passphrase?

Debugging and Support

How do I start an Address Range Scrub (ARS)?

ipmctl currently does not support this. However, one can use ndctl on Linux:

1. Run ndctl start-scrub to start ARS triggered by OS
2. Run ndctl wait-scrub
3. Run ipmctl show -d ARSStatus –dimm

How do I record a PBR?

1. execute ipmctl start -session -mode record
2. run any commands to be recorded
3. execute ipmctl dump -destination myrecording.pbr -session
4. execute ipmctl stop -session

What can cause a DCPMM to be marked non-functional?

A DCPMM is non-functional if at most points in our DCPMM initialization process an error is received. The function is viewable here. Some areas include:

• Control region structure (NFIT). Includes interleaves.
• DDRT interface
• Get DCPMM info does not respond
• Cannot read/initialize PCD (regions, namespaces)

Does not cause non-functional status:

• Cannot acquire security state.
• DCPMM determined to be unmanageable. This can occur when the FIS version is too old, too new (major version), or if the target device is an unsupported product.

This is distinct from:

• Fatal: DCPMM is media disabled. In this case the DCPMM is still responsive over DDRT small payload so it is not considered non-functional.

Limitations and Constraints

Why is impctl unable to create a fsdax namespaces?

A fsdax namespace can only be created when running on Linux because they are considered "proprietary" to Linux. Existing namespaces should be detected regardless of operating system.

Security

How do I recover my DCPMM if I have lost my user passphrase?

Unfortunately ipmctl is not able to help.

The DCPMM can be securely erased to make it accessable again though the contents will be lost. This capability may be available in a BIOS menu or via an OEM utility.

On in Intel reference BIOS, enter the BIOS menu and select Socket Configuration/Memory Configuration/NGN Configuration/NGNVM DIMM/Secure Erase Unit which results in a SecureErase request before Config Lockdown.