Script for manage swap on:
- zswap - Enable/Configure
- zram - Autoconfigurating for swap
- files - (sparse files for saving space, support btrfs)
- block devices - auto find and do swapon
It is configurable in /etc/systemd/swap.conf.
Additional terms:
- SwapFC (File Chunked) - provide a dynamic swap file allocation/deallocation
/etc/systemd/swap.conf
/usr/lib/systemd/system/systemd-swap.service
/usr/bin/systemd-swap
# systemctl enable systemd-swap
Arch: in the community.
- Debian: use package.sh in git repo
$ git clone https://github.com/Nefelim4ag/systemd-swap.git
$ ./systemd-swap/package.sh debian
$ sudo dpkg -i ././systemd-swap/systemd-swap-*any.deb
- Fedora: use package.sh $
$ git clone https://github.com/Nefelim4ag/systemd-swap.git
$ ./systemd-swap/package.sh fedora f28
$ sudo dnf install ./systemd-swap/systemd-swap-*noarch.rpm
- Manual
$ git clone https://github.com/Nefelim4ag/systemd-swap.git
$ sudo make install
Q: WTF?! Why you merge swapFC and swapFU?
A: That simplify testing of swapFC code and make code more generic
Q: How can i migrate config swapFU from 3.X to 4.X?
A: Most of switches are same, to get configuration like swapFU from swapFC, set swapfc_max_count to 1 and swapfc_chunk_size to size of swapFU.
Q: Do we need to activate both zram and zswap?
A: Nope, it's useless, as zram is a compressed RAM DISK, but zswap is a compressed "writeback" CACHE on swap file/disk.
Q: Do i need use swapfc_force_use_loop on swapFC?
A: Nope, as you wish really, native swapfile must work faster and it's more safe in OOM condition in comparison to loop backed scenario.
Q: When would we want a certain configuration?
A: In most cases (Notebook, Desktop, Server) it's enough to enable zswap + swapfc (On server tuning of swapfc can be needed).
In case where SSD used, and you care about flash wear, use only ZRam.
Q: Where is the swap file located?
A: Read carefully swap.conf
Q: Can we use this to enable hibernation?
A: Nope as hibernation wants a persistent fs blocks and wants access to swap data directly from disk, this will not work on: zram, swapfu, swapfc (without some magic of course).
- For zram support: Dependence: util-linux >= 2.26
- If you use zram not for only swap, use kernel 4.2+ or please add rule for modprobe like:
options zram max_devices=32
- For check your configuration :
cat /proc/sys/vm/swappiness
cat /proc/sys/vm/vfs_cache_pressure
- Recomended configuration for Desktop :
echo vm.swappiness=5 | sudo tee -a /etc/sysctl.d/99-sysctl.conf
echo vm.vfs_cache_pressure=50 | sudo tee -a /etc/sysctl.d/99-sysctl.conf
sudo sysctl -p /etc/sysctl.d/99-sysctl.conf
- If you have install Systemd Swap check configuration :
nano /etc/systemd/swap.conf
zram_enabled=0
zswap_enabled=1
swapfc_enabled=1
- Stop your swap :
swapoff -a
- Need to remove swap on fstab :
nano /etc/fstab
- Remove your swap :
# For Ubuntu 18.04
sudo rm -f /swapfile
# For Centos 7
lvremove -Ay /dev/centos/swap
lvextend -l +100%FREE centos/root
- Remove Swap from Grub
# For Ubuntu remove resume* in grub
nano /etc/default/grub
# For Centos 7 remove rd.lvm.lv=centos/swap*
nano /etc/default/grub
# For Manjaro remove resume* in grub & mkinitcpio
nano /etc/default/grub
nano /etc/mkinitcpio.conf
- Remove Swap from Grub
# For Ubuntu
update-grub
# For Centos 7
update-grub
# For Manjaro
update-grub
mkinitcpio -P