46 lines
1.8 KiB
Markdown
46 lines
1.8 KiB
Markdown
### Description :
|
|
|
|
Booting on a snapshot in read-only mode can be tricky.
|
|
An elegant way is to boot this snapshot using overlayfs (included in the kernel ≥ 3.18).
|
|
|
|
Using overlayfs, the booted snapshot will behave like a live-cd in non-persistent mode.
|
|
The snapshot will not be modified, the system will be able to boot correctly, because a writeable folder will be included in the ram.
|
|
(no more problems due to `/var` not open for writing)
|
|
|
|
Any changes in this system thus started will be lost when the system is rebooted/shutdown.
|
|
|
|
To do this, it is necessary to modify the initramfs.
|
|
This means that any snapshot that does not include this modified initramfs will not be able to benefit from it.
|
|
(except for separate boot partitions)
|
|
#
|
|
### Installation :
|
|
#### Arch Linux
|
|
1.
|
|
`Pacman -S grub-btrfs`
|
|
Or if you use git
|
|
copy the `overlay_snap_ro-install` file to `/etc/initcpio/install/grub-btrfs-overlayfs`
|
|
copy the `overlay_snap_ro-hook` file to `/etc/initcpio/hooks/grub-btrfs-overlayfs`
|
|
You must rename the files. (I did it above)
|
|
|
|
For example :
|
|
`overlay_snap_ro-install` to `grub-btrfs-overlayfs`
|
|
`overlay_snap_ro-hook` to `grub-btrfs-overlayfs`
|
|
Keep in mind that the files must have exactly the same name to ensure a match.
|
|
|
|
2.
|
|
Edit the file `/etc/mkinitcpio.conf`
|
|
Added hook `grub-btrfs-overlayfs` at the end of the line `HOOKS`.
|
|
|
|
For example :
|
|
`HOOKS=(base udev autodetect modconf block filesystems keyboard fsck grub-btrfs-overlayfs)`
|
|
You notice that the name of the `hook` must match the name of the 2 installed files. (don't forget it)
|
|
|
|
3.
|
|
Re-generate your initramfs
|
|
`mkinitcpio -P` (option -P means, all preset present in `/etc/mkinitcpio.d`)
|
|
|
|
#### Other distribution
|
|
Refer to your distribution's documentation
|
|
or contribute to this project to add a paragraph.
|
|
#
|