Custom Installation

In the present context, “custom installation” refers to things like manual partitioning, setting up LVM and RAID, and manual LUKS encryption configuration.

Qubes 4.0

Installer Defaults

For reference, these are the typical defaults for a single disk with legacy boot:

Mount Point: /boot
Desired Capacity: 1024 MiB
Device Type: Standard Partition
File System: ext4
Name: (none)

Mount Point: /
Desired Capacity: (your choice)
Device Type: LVM Thin Provisioning
Volume Group: qubes_dom0
File System: ext4
Name: root

Mount Point: (none)
Desired Capacity: 10 GiB
Device Type: LVM
Volume Group: qubes_dom0
File System: swap
Name: swap
SUMMARY OF CHANGES

Order   Action              Type                    Device              Mount point

1       Destroy Format      Unknown                 Disk (sda)
2       Create Format       partition table (MSDOS) Disk (sda)
3       Create Device       partition               sda1 on Disk
4       Create Format       ext4                    sda1 on Disk        /boot
5       Create Device       partition               sda2 on Disk
6       Create Format       LUKS                    sda2 on Disk
7       Create Device       luks/dm-crypt           luks-sda2
8       Create Format       physical volume (LVM)   luks-sda2
9       Create Device       lvmvg                   qubes_dom0
10      Create Device       lvmthinpool             qubes_dom0-pool00
11      Create Device       lvmthinlv               qubes_dom0-root
12      Create Device       lvmlv                   qubes_dom0-swap
13      Create Format       swap                    qubes_dom0-swap
14      Create Format       ext4                    qubes_dom0-root     /

Typical Partition Schemes

If you want your partition/LVM scheme to look like the Qubes default but with a few tweaks, follow this example. With a single disk, the result should look something like this:

NAME                                SIZE    TYPE    MOUNTPOINT
sda                                         disk
├──sda1                               1G    part    /boot
└──sda2                                     part
   └──luks-<UUID>                           crypt
      ├──qubes_dom0-pool00_tmeta            lvm
      ├──qubes_dom0-pool00_tdata            lvm
      └──qubes_dom0-swap                    lvm     [SWAP]

Encryption Defaults

By default, cryptsetup 1.7.5 will create a LUKS/dm-crypt volume as follows:

Version:            1
Cipher name:        aes
Cipher mode:        xts-plain64
Hash spec:          sha256
$ cryptsetup --help
[...]
Default compiled-in device cipher parameters:
        loop-AES: aes, Key 256 bits
        plain: aes-cbc-essiv:sha256, Key: 256 bits, Password hashing: ripdemd160
        LUKS1: aes-xts-plain64, Key: 256 bits, LUKS header hashing: sha256, RNG: /dev/urandom

This means that, by default, Qubes inherits these upstream defaults:

  • AES-128 [1][2][3]
  • SHA-256
  • /dev/urandom
  • probably an iter-time of one second

If, instead, you’d like to use AES-256, SHA-512, /dev/random, and a longer iter-time, for example, you can configure encryption manually by following the instructions below.

Example: Custom LUKS Configuration

Boot into the Qubes installer, then press ctrl+alt+F2 to get a virtual console.

  1. (Optional) Wipe the disk:

     # dd if=/dev/zero of=/dev/sda bs=1M status=progress && sync
    
  2. Create partitions:

     # fdisk /dev/sda
    

    Follow the steps to create two partitions:

    • ~500MiB-1GiB for /boot
    • The rest for / (might want to leave some for overprovisioning if it’s an SSD)
  3. Create LUKS encrypted volume:

     # cryptsetup -v --hash sha512 --cipher aes-xts-plain64 --key-size 512 --use-random --iter-time 10000 --verify-passphrase luksFormat /dev/sda2
    
  4. Open encrypted volume:

     # cryptsetup open /dev/sda2 luks
    
  5. Create LVM volumes:

     # pvcreate /dev/mapper/luks
     # vgcreate qubes_dom0 /dev/mapper/luks
     # lvcreate -n swap -L 10G qubes_dom0
     # lvcreate -T -l +100%FREE qubes_dom0/pool00
     # lvcreate -V1G -T qubes_dom0/pool00 -n root
     # lvextend -L <size_of_pool00> /dev/qubes_dom0/root
    
  6. Proceed with the installer. At the disk selection screen, select:

     [x] I will configure partitioning.
     [ ] Encrypt my data.
    

Decrypt your partition, then assign /, /boot, and swap. Proceed normally from there.

Qubes 3.2

Installer Defaults

For reference, these are the defaults for a single disk:

Mount Point: /
Desired Capacity: (your choice)
Device Type: LVM
Volume Group: qubes_dom0
File System: ext4
Name: root

Mount Point: /boot
Desired Capacity: 500 MiB (recommended)
Device Type: Standard Partition
File System: ext4

Mount Point: (none)
Desired Capacity: 9.44 GiB (recommended)
Device Type: LVM
Volume Group: qubes_dom0
File System: swap
Name: swap

Typical Partition Schemes

If you want your partition/LVM scheme to look like the Qubes default but with a few tweaks, follow these examples. With a single disk, the result should look something like this:

    NAME                        TYPE    MOUNTPOINT
    sda                         disk
    ├──sda1                     part    /boot
    └──sda2                     part
       └──luks-<UUID>           crypt
          ├──qubes_dom0-root    lvm     /
          └──qubes_dom0-swap    lvm     [SWAP]

If you’re using mdadm software RAID, it should look something like this:

    NAME                           TYPE    MOUNTPOINT
    sda                            disk
    ├──sda1                        part
    │  └──md0                      raid1   /boot
    └──sda2                        part
       └──md1                      raid1
          └──luks-<UUID>           crypt
             ├──qubes_dom0-root    lvm     /
             └──qubes_dom0-swap    lvm     [SWAP]
    sdb                            disk
    ├──sdb1                        part
    │  └──md0                      raid1   /boot
    └──sdb2                        part
       └──md1                      raid1
          └──luks-<UUID>           crypt
             ├──qubes_dom0-root    lvm     /
             └──qubes_dom0-swap    lvm     [SWAP]

Example: LVM on LUKS on RAID0

Boot into the Qubes installer, then press ctrl+alt+F2 to get a virtual console.

  1. (Optional) Wipe both disks:

     # hdparm --user-master u --security-set-pass pass /dev/sda
     # time hdparm --user-master u --security-erase-enhanced pass /dev/sda
     # hdparm --user-master u --security-set-pass pass /dev/sdb
     # time hdparm --user-master u --security-erase-enhanced pass /dev/sdb
    
  2. Create desired partitions:

     # fdisk /dev/sda
     <create partitions>
     # fdisk /dev/sdb
     <create partitions>
    
  3. Create RAID devices:

     # mdadm --create --verbose /dev/md0 --level=mirror --raid-devices=2 /dev/sda1 /dev/sdb1
     # mdadm --create --verbose /dev/md1 --level=mirror --raid-devices=2 /dev/sda2 /dev/sdb2
    
  4. Create LUKS encrypted volume:

     # cryptsetup -v --hash sha512 --cipher aes-xts-plain64 --key-size 512 --use-random --iter-time 5000 --verify-passphrase luksFormat /dev/md1
    
  5. Open encrypted volume:

     # cryptsetup open /dev/md1 luks
    
  6. Create LVM volumes:

     # pvcreate /dev/mapper/luks
     # vgcreate qubes_dom0 /dev/mapper/luks
     # lvcreate -n swap -L 10G qubes_dom0
     # lvcreate -n root -l +100%FREE qubes_dom0
    
  7. Proceed with installer. At the disk selection screen, select:

     [x] I will configure partitioning.
     [ ] Encrypt my data.
    

Continue normally from here.

Qubes 3.1

Manual Encryption Configuration

Qubes OS uses full disk encryption (FDE) by default. If you are an advanced user who wishes to customize your encryption parameters during installation, this page can help.

The Qubes installer uses cryptsetup (LUKS/dm-crypt) under the hood. You can configure the encryption options while installing Qubes as follows:

  1. Boot into the installer. Wait for first GUI screen to appear where it asks about language/localization .
  2. Press Ctrl+Alt+F2 on your keyboard to escape to a shell session. (If you are on a laptop, and your laptop keyboard does not work properly, you may have to plug in a USB keyboard.)
  3. Check and adjust the partitioning on the drive you plan to install to with parted. For example, you can leave the partition table as msdos/MBR type, then create a 500 MB ext4 boot partition, a 10 GB swap partition, and use the rest of the drive (minus overprovisioning space for SSDs) for the root partition.
  4. Run to set the LUKS options as you like and set the passphrase:

    # cryptsetup <options> luksFormat <partition>
    

    For example:

    # cryptsetup -v --hash sha512 --cipher aes-xts-plain64 --key-size 512 --use-random --iter-time 5000 --verify-passphrase luksFormat /dev/sda2
    
  5. (Optional) Make sure the new container works:

    # cryptsetup open /dev/sda2 test
    # mkfs.ext4 /dev/mapper/test
    # mount /dev/mapper/test /mnt/test
    # umount /dev/mapper/test
    # cryptsetup close test
    
  6. Everything should be set with the preparation, so press Ctrl+Alt+F7 to go back to the GUI installer.
  7. Continue installing as usual. When you get to the disk partitioning/allocation part, pay attention.
  8. When you select the disk, it may complain about only having a few MB of space. Uncheck the “Encrypt and ask me about the passphrase later” box and press the “Custom” button.
  9. In this menu, you should see the unencrypted boot partition and the encrypted LUKS partitions you created earlier. You must unlock the LUKS partition here, i.e. enter passphrases.
  10. Set the mount points on these partitions once they are decrypted. (This part may be a bit glitchy, but you should be able to get it working after a reboot.) For example, set the mount point for the primary LUKS partition as /. Make sure the “Encrypted” box stays checked and that you check the “Format” box (required for the root partition). Similarly, set /boot as the mount point for the unencrypted boot partition and swap as the mount point for the swap partition.
  11. Now the install should complete without any other issues. When it’s finished, you’ll have LUKS-encrypted partitions with the options you chose above. You can verify this command in dom0:

    # cryptsetup luksDump <partition>
    

    For example:

    # cryptsetup luksDump /dev/sda2