VM Live Mode: Alternative ro-mode-init Configuration

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The ro-mode-init automatically enables live-mode if it detects that the disk is set to read-only.

This is an alternative to the default grub-live based method documented on VM Live Mode.

Introduction[edit]

ro-mode-init is currently less tested than grub-live (Live Mode).

Warning: This is for testers-only!

  • Does not work on newer builds of Kicksecure because these come with dracut by default.
  • This is for systems with initramfs-tools only.

ro-mode-init has not been ported to dracut yet. Theoretically this probably possible but this has not happened yet.

Preliminary Steps[edit]

1. Backup.

  • Option 1: Create a snapshot of your VM; or
  • Option 2: Alternatively backup the /boot folder.

Click = Copy Copied to clipboard! sudo cp -a /boot /boot.back

2. Install ro-mode-init.

Install package(s) ro-mode-init following these instructions

1 Platform specific notice.

2 Update the package lists and upgrade the systemOnion Logo.

Click = Copy Copied to clipboard! sudo apt update && sudo apt full-upgrade

3 Install the ro-mode-init package(s).

Using apt command line --no-install-recommends optionOnion Logo is in most cases optional.

Click = Copy Copied to clipboard! sudo apt install --no-install-recommends ro-mode-init

4 Platform specific notice.

  • Kicksecure: No special notice.
  • Kicksecure-Qubes: Shut down Template and restart App Qubes based on it as per Qubes Template ModificationOnion Logo.

5 Done.

The procedure of installing package(s) ro-mode-init is complete.

3. Update initial ramdisk. [1]

Click = Copy Copied to clipboard! sudo update-initramfs -u

4. Set the VM disk to read-only.

The read-only VM setting is necessary (see below), otherwise the VM disk will always boot into persistent mode.

Read-only VM Setting[edit]

VirtualBox[edit]

Read-only disk on VirtualBox[edit]

To boot into live mode, apply the following steps.

Set the VirtualBox virtual harddrive to read-only.

1. Power off the machine.

2. Open setting window of the machine and set the type of storage device controller from AHCI to LsiLogic SAS.

VirtualBox → Settings → Storage → Type: LsiLogic SAS → OK

3. Learn the syntax.

Do not run the following command. Only look at it.

TODO research: lsilogicsas might no longer work because nowadays using IntelAhci. So commands below need adjustment. How? This is difficult because undocumented by VirtualBox. 

VBoxManage setextradata vmname "VBoxInternal/Devices/lsilogicsas/0/LUN#0/AttachedDriver/Config/ReadOnly" 1

Replace vmname with the name of the actual VM name.

4. On the command line run.

Kicksecure Xfce example:

Click = Copy Copied to clipboard! VBoxManage setextradata Kicksecure-Xfce "VBoxInternal/Devices/lsilogicsas/0/LUN#0/AttachedDriver/Config/ReadOnly" 1

Kicksecure CLI example:

Click = Copy Copied to clipboard! VBoxManage setextradata Kicksecure-CLI "VBoxInternal/Devices/lsilogicsas/0/LUN#0/AttachedDriver/Config/ReadOnly" 1

Read-write disk on VirtualBox[edit]

To boot into read-write mode again, simply revert this change.

  1. Power off the machine.
  2. From the command line run.

Use the syntax below.

Click = Copy Copied to clipboard! VBoxManage setextradata vmname "VBoxInternal/Devices/lsilogicsas/0/LUN#0/AttachedDriver/Config/ReadOnly"

Replace vmname with the name of the actual VM name.

KVM[edit]

Read-only disk on KVM[edit]

To boot into live mode, apply the following steps:

  1. Power off the machine.
  2. Set the hard disk to read-only in the virt-manager GUI.
  3. Power on the machine and select to boot into live mode.

Read-write disk on KVM[edit]

To boot into normal mode again, simply revert this change:

  1. Power off the machine.
  2. Set the hard disk to read-write in the virt-manager GUI.
  3. Power on the machine and boot into read-write mode.

Live Mode Indicator Systray[edit]

https://github.com/Kicksecure/desktop-config-dist/blob/master/usr/share/livecheck/livecheck.sharchive.org iconarchive.today icon

Debugging[edit]

An inconsistent filesystem will likely result in errors during booting in live mode. For instance, inconsistencies can arise when the VM is killed instead of performing a normal shutdown in persistent mode. Therefore to ensure it is consistent, run fsck in persistent mode. Debian automatically does this during boot. VMs running in live mode can be killed without problems.

In the case of non-fsck related errors using ro-mode-init (like dropping to an initramfs shell), add the following to the kernel command line/GRUB menu for easier debugging:

Click = Copy Copied to clipboard! debug=1 break=init-premount

Footnotes[edit]

  1. ↑ Required for now but not forever.
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