zswap-cli - Man Page

command-line tool to control ZSwap Linux kernel module

Synopsis

zswap-cli [OPTION...]

Description

ZSwap-cli is a simple command-line tool to control ZSwap Linux kernel module.

Command-Line Options

--config

Get options from the configuration file instead of the cmdline.

--env

Get options from the environment variables instead of the cmdline.

--stats

Get statistics and current settings of ZSwap kernel module.

Supported values:

  • 0 (default) - print both ZSwap kernel module settings and debug information;
  • 1 - print ZSwap kernel module settings;
  • 2 - print ZSwap kernel module usage summary;
  • 3 - print ZSwap kernel module debug information.

-e, --enabled

Enable or disable ZSwap kernel module.

-s, --same_filled_pages_enabled

Enable or disable memory pages deduplication.

-p, --max_pool_percent

The maximum percentage of memory that the compressed pool can occupy.

-c, --compressor

The default compression algorithm.

-z, --zpool

The kernel’s zpool type.

-a, --accept_threhsold_percent

The threshold at which ZSwap would start accepting pages again after it became full.

-h, --help

Print help message and exit.

Environment Options

ZSwap-cli support of getting options from environment variables.

Supported options

  • ZSWAP_ENABLED_VALUE - enable (Y) or disable (N) ZSwap kernel module.
  • ZSWAP_SAME_FILLED_PAGES_ENABLED_VALUE - enable (Y) or disable (N) memory pages deduplication.
  • ZSWAP_MAX_POOL_PERCENT_VALUE - the maximum percentage of memory that the compressed pool can occupy (integer from 1 to 100).
  • ZSWAP_COMPRESSOR_VALUE - the default compression algorithm.
  • ZSWAP_ZPOOL_VALUE - the kernel’s zpool type.
  • ZSWAP_ACCEPT_THREHSOLD_PERCENT_VALUE - the threshold at which ZSwap would start accepting pages again after it became full (integer from 1 to 100).

Forwarding options

Export environment options using export command:

export ZSWAP_ENABLED_VALUE=Y
export ZSWAP_SAME_FILLED_PAGES_ENABLED_VALUE=Y
export ZSWAP_MAX_POOL_PERCENT_VALUE=60
export ZSWAP_COMPRESSOR_VALUE=zstd
export ZSWAP_ZPOOL_VALUE=z3fold
export ZSWAP_ACCEPT_THREHSOLD_PERCENT_VALUE=40

Start application with --env command-line argument:

sudo zswap-cli --env

Configuration Files

ZSwap-cli support of getting options from the configuration files.

Supported options

  • enabled - enable (Y) or disable (N) ZSwap kernel module.
  • same_filled_pages_enabled - enable (Y) or disable (N) memory pages deduplication.
  • max_pool_percent - the maximum percentage of memory that the compressed pool can occupy (integer from 1 to 100).
  • compressor - the default compression algorithm.
  • zpool - the kernel’s zpool type.
  • accept_threhsold_percent - the threshold at which ZSwap would start accepting pages again after it became full (integer from 1 to 100).

Forwarding options

Start application with --config command-line argument:

sudo zswap-cli --config /path/to/zswap-cli.conf

Exit Status

0: Successful exit.

1: Insuffient access rights.

Systemd Unit

After installation, the systemd-unit zswap-cli.service will be added.

Changing settings

All settings are stored in the /etc/zswap-cli/zswap-cli.conf configuration file. It uses standard key-value systax.

Enabling unit

Enable systemd-unit and run it on system startup:

sudo systemctl enable --now zswap-cli.service

Disabling unit

Disable systemd-unit and stop runing it on system startup:

sudo systemctl disable zswap-cli.service

Running unit

You can also run systemd-unit without adding it to startup.

Start unit and enable ZSwap:

sudo systemctl start zswap-cli.service

Stop unit and disable ZSwap:

sudo systemctl stop zswap-cli.service

Authors

Copyright (c) 2020 - 2021 EasyCoding Team and contributors.

Info

General Commands Manual