> For the complete documentation index, see [llms.txt](https://docs.pmem.io/ndctl-user-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pmem.io/ndctl-user-guide/v67/master.md).

# NDCTL User Guide

## Introduction

`ndctl` is a utility for managing the Linux LIBNVDIMM Kernel subsystem. It is designed to work with various non-volatile memory devices (NVDIMMs) from different vendors. The LIBNVDIMM subsystem defines a kernel device model and control message interface for platform NVDIMM resources like those defined by the [ACPI v6.0](http://www.uefi.org/sites/default/files/resources/ACPI_6_0_Errata_A.PDF) NFIT (**N**VDIMM **F**irmware **I**nterface **T**able). The latest [ACPI ](http://www.uefi.org/specifications)and [UEFI ](http://www.uefi.org/specifications)specifications can be found at [uefi.org](http://www.uefi.org). Operations supported by `ndctl` include:

* Provisioning capacity (namespaces)
* Enumerating Devices
* Enabling and Disabling NVDIMMs, Regions, and Namespaces
* Managing NVDIMM Labels

## What's new in v67

This release incorporates functionality up to the 5.4 kernel, and adds a number of bug fixes, and improvements.

Highlights include small changes for PowerPC compatibility, improvements to the dax.sh unit test to detect failures in mapping huge pages, support for the 'security frozen' attribute, user experience improvements for the daxctl-reconfigure-device command, including an option to specify movable vs. non-movable state for onlining memory, and an option to allow create-namespaces to create a maximal configuration until it exhausts all available region capacity.

Commands: 

* [create-namespace](/ndctl-user-guide/v67/ndctl-man-pages/ndctl-create-namespace.md): add --continue option 
* [daxctl-reconfigure-device](/ndctl-user-guide/v67/daxctl-man-pages/daxctl-reconfigure-device.md): add --no-movable option 
* [daxctl-reconfigure-device](/ndctl-user-guide/v67/daxctl-man-pages/daxctl-reconfigure-device.md): display movable state in listings 
* [daxctl-reconfigure-device](/ndctl-user-guide/v67/daxctl-man-pages/daxctl-reconfigure-device.md): detect races in memory onlining 
* [ndctl-freeze-security](/ndctl-user-guide/v67/ndctl-man-pages/ndctl-freeze-security.md): support for 'security frozen' attribute

APIs: 

* ndctl\_dimm\_security\_is\_frozen 
* daxctl\_memory\_is\_movable 
* daxctl\_memory\_online\_no\_movable


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.pmem.io/ndctl-user-guide/v67/master.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.