chmem

configure memory hotplug state

TLDR

Set a memory block offline

$ sudo chmem -b -d [block_number]

Set a memory block online

$ sudo chmem -b -e [block_number]

Set a memory range offline

$ sudo chmem -d 0x[start_address]-0x[end_address]

Set a memory range online

$ sudo chmem -e 0x[start_address]-0x[end_address]

Set memory online in a specific zone

$ sudo chmem -e 0x[start_address] -z [Movable]

SYNOPSIS

chmem [options] size|range|block

chmem modifies the state of memory blocks in a Linux system, bringing them online or offline. This is primarily used in virtualized environments for memory hotplug operations.Memory blocks are chunks of physical memory that can be individually managed. The tool allows dynamic memory management without rebooting.

PARAMETERS

-b, --block

Operate on memory blocks by block number

-d, --disable

Set memory offline

-e, --enable

Set memory online

-z, --zone zone

Assign memory to a specific zone (DMA, DMA32, Normal, Movable)

-h, --help

Display help

INSTALL

sudo apt install util-linux

sudo dnf install util-linux

sudo pacman -S util-linux

sudo apk add util-linux-misc

sudo zypper install util-linux

brew install util-linux

nix profile install nixpkgs#util-linux

CAVEATS

Requires root privileges. Not all systems support memory hotplug. Memory containing kernel data or in-use pages cannot be offlined. Virtual machines may require specific configuration to support memory hotplug.