DAXCTL-ONLINE-MEMORY(1) daxctl Manual DAXCTL-ONLINE-MEMORY(1)

# [NAME](#NAME)

daxctl-online-memory - Online the memory for a device that is in system-ram mode

# [SYNOPSIS](#SYNOPSIS)

```
daxctl online-memory <dax0.0> [<dax1.0>...<daxY.Z>] [<options>]
```

# [EXAMPLES](#EXAMPLES)

•Reconfigure dax0.0 to system-ram mode, don’t online the memory

```
# daxctl reconfigure-device --mode=system-ram --no-online --human dax0.0
{


  "chardev":"dax0.0",


  "size":"7.87 GiB (8.45 GB)",


  "target_node":2,


  "mode":"system-ram"
}
```

•Online the memory separately

```
# daxctl online-memory dax0.0
dax0.0: 62 new sections onlined
onlined memory for 1 device
```

•Onlining memory when some sections were already online

```
# daxctl online-memory dax0.0
dax0.0: 1 section already online
dax0.0: 61 new sections onlined
onlined memory for 1 device
```

# [DESCRIPTION](#DESCRIPTION)

Online the memory sections associated with a device that has been converted to the system-ram mode. If one or more blocks are already online, print a message about them, and attempt to online the remaining blocks.

This is complementary to the *daxctl-reconfigure-device* command, when used with the *--no-online* option to skip onlining memory sections immediately after the reconfigure. In these scenarios, the memory can be onlined at a later time using *daxctl-online-memory*.

# [OPTIONS](#OPTIONS)

-r, --region=

Restrict the operation to devices belonging to the specified region(s). A device-dax region is a contiguous range of memory that hosts one or more /dev/daxX.Y devices, where X is the region id and Y is the device instance id.

--no-movable

*--movable* is the default. This can be overridden to online new memory such that it is not *movable*. This allows any allocation to potentially be served from this memory. This may preclude subsequent removal. With the *--movable* behavior (which is default), kernel allocations will not consider this memory, and it will be reserved for application use.

-u, --human

By default the command will output machine-friendly raw-integer data. Instead, with this flag, numbers representing storage size will be formatted as human readable strings with units, other fields are converted to hexadecimal strings.

-v, --verbose

Emit more debug messages

# [COPYRIGHT](#COPYRIGHT)

Copyright © 2016 - 2022, Intel Corporation. License GPLv2: GNU GPL version 2 &lt;http://gnu.org/licenses/gpl.html&gt;. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

# [SEE ALSO](#SEE_ALSO)

[daxctl-reconfigure-device(1)](/man/os/ndctl/daxctl-reconfigure-device.1),daxctl-offline-memory\[1]

2026-08-31 daxctl

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Document: daxctl-online-memory(1) from ndctl 85-r2 (Chainguard OS)
Source: https://github.com/pmem/ndctl