diff options
author | Johannes Stoelp <johannes.stoelp@gmail.com> | 2022-09-11 18:53:28 +0200 |
---|---|---|
committer | Johannes Stoelp <johannes.stoelp@gmail.com> | 2022-09-11 18:53:28 +0200 |
commit | de78630d8ac5a474768de7f6aaa1843b6195e04b (patch) | |
tree | 2b92c5d8bff5d86d76ec894fef37ba903144c91e /src/linux | |
parent | 8de64474ded169db55cdd34be9c020ed13c4e5e7 (diff) | |
download | notes-de78630d8ac5a474768de7f6aaa1843b6195e04b.tar.gz notes-de78630d8ac5a474768de7f6aaa1843b6195e04b.zip |
linux: added swap notes
Diffstat (limited to 'src/linux')
-rw-r--r-- | src/linux/README.md | 1 | ||||
-rw-r--r-- | src/linux/swap.md | 50 |
2 files changed, 51 insertions, 0 deletions
diff --git a/src/linux/README.md b/src/linux/README.md index b21cc55..00e7e68 100644 --- a/src/linux/README.md +++ b/src/linux/README.md @@ -4,3 +4,4 @@ - [coredump](./coredump.md) - [ptrace_scope](./ptrace_scope.md) - [cryptsetup](./cryptsetup.md) +- [swap](./swap.md) diff --git a/src/linux/swap.md b/src/linux/swap.md new file mode 100644 index 0000000..1a45883 --- /dev/null +++ b/src/linux/swap.md @@ -0,0 +1,50 @@ +# swap + +## List active swap areas + +```sh +# procfs +cat /proc/swaps + +# cli tool +swapon --show +``` + +## Manual swapfile setup + +```sh +# One time: +# Create and initialize swapfile. +# mkswap will initialize swap area over full filesize by default. +sudo dd if=/dev/zero of=/swapfile bs=1G count=1 +mkswap /swapfile + +# Enable swap file (until next reboot). +swapon /swapfile + +# Persistent setup of swap file. +echo "/swapfile none swap sw 0 0" | sudo tee -a /etc/fstab + +# Disable swap file (until next reboot). +swapoff /swapfile +``` +> Recommended file permissions `0600` and file owner `uid=0 (root)`. + +## Using `dphys-swapfile` service. + +Dynamically computes size of swap file based on installed RAM. + +```sh +# Setup and enable swap based on /etc/dphys-swapfile. +dphys-swapfile setup +dphys-swapfile swapon + +# Disable swap on configured file. +dphys-swapfile swapoff +``` + +> Usually comes with a script to be automatically run at system startup and shutdown. +> For example as `systemd` service: +> ``` +> systemctl status dphys-swapfile +> ``` |