qubes-doc/installing/custom-install.md

---
layout: doc
title: Custom Installation
permalink: /doc/custom-install/
redirect_from:
 - /doc/encryption-config/
---

# Custom Installation

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


## 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]][cryptsetup-faq][[2]][dm-crypt][[3]][tomb-238]
 - 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)

4. 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

5. Open encrypted volume:

        # cryptsetup open /dev/sda2 luks

6. 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

8. 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.


[cryptsetup-faq]: https://gitlab.com/cryptsetup/cryptsetup/wikis/FrequentlyAskedQuestions
[dm-crypt]: https://wiki.archlinux.org/index.php/dm-crypt/Device_encryption
[tomb-238]: https://github.com/dyne/Tomb/issues/238