Booster is a fast initramfs generator similar to mkinitcpio and dracut. Booster is inspired by distri project and aims to create a small and fast init image.
Booster consists of two major components:
- Initramfs generator
/usr/bin/boosteruser-space tool. It is responsible for initramfs image generation.
- Generated images that are usually located at
/boot/and used by the system boot loader to boot Linux OS.
Install booster. The package installation hook will generate initramfs images, one per installed kernel (e.g. for linux, linux-lts). The images are located under
$ ls -lh /boot/booster*
-rwxr-xr-x 1 root root 4.0M Dec 16 16:20 /boot/booster-linux.img
Or the image can be built manually:
$ booster build mybooster.img
Booster generator configuration is located at
/etc/booster.yaml. If there is no configuration file then the default configuration (host-specific images, no network) is used.
The configuration file helps to override the default behaviour. See booster(1) § CONFIG FILE for detailed information.
Regenerate booster images
Once you are done with booster configuration you need to update booster images at
/boot. An image can be generated manually with
booster build booster-foo.img or using a convenience script
/usr/lib/booster/regenerate_images that iterates over all installed kernels and generates booster image for each of them.
Boot loader configuration
Once the image is generated it is time to configure the boot loader.
If the configuration relies on automatic detection already, no additional configuration change is necessary. rEFInd supports initrd files named booster*.
If you specify the initramfs path manually, either in refind.conf or in manual boot stanzas, make sure to use the correct files names. I.e.
booster-linux.img instead of
To enable the new initramfs image with systemd-boot simply create a new boot loader entry like this one:
title Arch Linux with booster linux /vmlinuz-linux initrd /booster-linux.img options root=UUID=08f83949-bcbb-47bb-bc17-089aaa59e17e rw
Where the root filesystem is referenced by
UUID=08f83949-bcbb-47bb-bc17-089aaa59e17e. To find your root device UUID run
Booster supports LUKS based full-disk encryption out-of-the-box and Clevis too. The generator does not need any extra configuration. Yet, for the initramfs you need to append information about the LUKS partition where the root resides. This is done with either
rd.luks.name=LUKSUUID=LUKSNAME kernel parameter that need to be specified in the boot loader configuration file.
LUKSUUID specifies the UUID of the encrypted LUKS partition that needs to be unlocked by booster. The booster(1) § UUID parameters manual recommends that the UUID does not contain any quotes.
LUKSNAME specifies name of the unlocked partition (as in
/dev/mapper/LUKSNAME). See booster(1) § BOOT TIME KERNEL PARAMETERS for related options.
No image rebuild is required. Once the boot loader configuration is done, reboot the computer. After that you will see a
Enter passphrase for YOURROOT: prompt at boot time asking for a password for the encrypted root partition.
systemd style binding
Booster also supports partitions bound with systemd such as
If you use `systemd-fido2` then please install libfido2 package and add fido2-assert to the image using following configuration:
Regenerate the booster images. Booster will detect this configuration during boot and use the present YubiKey to unlock the drive.
If booster has issues and does not work as expected then please enable debug output that provides extra information about what is going on:
- for generator there is a
-debugcommand line flag:
- for init there is a
If you believe it is an issue with booster itself then please file a ticket here https://github.com/anatol/booster/issues
Early module loading
The are situations when some kernel modules need to be loaded early, at initramfs stage.
For example, if you need to load the
nvidia module, then use the following configuration setting:
And then regenerate booster images.
Booster generator fails with "too many open files" error
If you enabled
universal and see an error like
/usr/lib/modules/glue_helper.ko: pipe2: too many open files, then you need to increase per-process limit for open files. See Limits.conf#nofile.