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robertspierre
Asked: 2021-05-02 10:18:18 +0800 CST

Install another OS in double boot when I have Ubuntu in encrypted partition

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I have installed Ubuntu 20.10 with the "encrypted" option on.

Now I believe that in my disk there is an outer "container" with LUKS2 and an ext4 partition with the OS inside it.

Can I have Fedora 34 in double boot in this setting?

I would like to resize the "inside" ext4 partition to make another BTRFS partition along side it in which Fedora would reside, so also Fedora should be encrypted inside the LUKS2 container.

GRUB will ask me which OS I want to boot at startup.

Installing Fedora on ext4 would be fine as well.

But I am not sure if that is possible at all or would work at all.

EDIT:

I would like to resize nvme0n1p3_crypt to make room for the other OS

Output of lsblk

NAME                   MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
loop0                    7:0    0  99.2M  1 loop  /snap/core/10908
loop1                    7:1    0  99.1M  1 loop  /snap/core/10958
loop2                    7:2    0  32.3M  1 loop  /snap/snapd/11402
loop3                    7:3    0  32.3M  1 loop  /snap/snapd/11588
sda                      8:0    0 931.5G  0 disk  
└─intdata              253:3    0 931.5G  0 crypt /media/raffaele/intdata
nvme0n1                259:0    0 476.9G  0 disk  
├─nvme0n1p1            259:1    0   512M  0 part  /boot/efi
├─nvme0n1p2            259:2    0   732M  0 part  /boot
└─nvme0n1p3            259:3    0 475.7G  0 part  
  └─nvme0n1p3_crypt    253:0    0 475.7G  0 crypt 
    ├─vgkubuntu-root   253:1    0 474.8G  0 lvm   /
    └─vgkubuntu-swap_1 253:2    0   980M  0 lvm   [SWAP]

Output of findmnt

TARGET                                SOURCE         FSTYPE   OPTIONS
/                                     /dev/mapper/vgkubuntu-root
│                                                    ext4     rw,relatime,errors=remount-r
├─/sys                                sysfs          sysfs    rw,nosuid,nodev,noexec,relat
│ ├─/sys/kernel/security              securityfs     security rw,nosuid,nodev,noexec,relat
│ ├─/sys/fs/cgroup                    tmpfs          tmpfs    ro,nosuid,nodev,noexec,size=
│ │ ├─/sys/fs/cgroup/unified          cgroup2        cgroup2  rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/systemd          cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/devices          cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/net_cls,net_prio cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/freezer          cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/cpu,cpuacct      cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/blkio            cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/rdma             cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/memory           cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/pids             cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/hugetlb          cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ ├─/sys/fs/cgroup/perf_event       cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ │ └─/sys/fs/cgroup/cpuset           cgroup         cgroup   rw,nosuid,nodev,noexec,relat
│ ├─/sys/fs/pstore                    pstore         pstore   rw,nosuid,nodev,noexec,relat
│ ├─/sys/firmware/efi/efivars         efivarfs       efivarfs rw,nosuid,nodev,noexec,relat
│ ├─/sys/fs/bpf                       none           bpf      rw,nosuid,nodev,noexec,relat
│ ├─/sys/kernel/debug                 debugfs        debugfs  rw,nosuid,nodev,noexec,relat
│ ├─/sys/kernel/tracing               tracefs        tracefs  rw,nosuid,nodev,noexec,relat
│ ├─/sys/fs/fuse/connections          fusectl        fusectl  rw,nosuid,nodev,noexec,relat
│ └─/sys/kernel/config                configfs       configfs rw,nosuid,nodev,noexec,relat
├─/proc                               proc           proc     rw,nosuid,nodev,noexec,relat
│ └─/proc/sys/fs/binfmt_misc          systemd-1      autofs   rw,relatime,fd=28,pgrp=1,tim
│   └─/proc/sys/fs/binfmt_misc        binfmt_misc    binfmt_m rw,nosuid,nodev,noexec,relat
├─/dev                                udev           devtmpfs rw,nosuid,noexec,relatime,si
│ ├─/dev/pts                          devpts         devpts   rw,nosuid,noexec,relatime,gi
│ ├─/dev/shm                          tmpfs          tmpfs    rw,nosuid,nodev
│ ├─/dev/mqueue                       mqueue         mqueue   rw,nosuid,nodev,noexec,relat
│ └─/dev/hugepages                    hugetlbfs      hugetlbf rw,relatime,pagesize=2M
├─/run                                tmpfs          tmpfs    rw,nosuid,nodev,noexec,relat
│ ├─/run/lock                         tmpfs          tmpfs    rw,nosuid,nodev,noexec,relat
│ └─/run/user/1000                    tmpfs          tmpfs    rw,nosuid,nodev,relatime,siz
│   ├─/run/user/1000/gvfs             gvfsd-fuse     fuse.gvf rw,nosuid,nodev,relatime,use
│   └─/run/user/1000/doc              portal         fuse.por rw,nosuid,nodev,relatime,use
├─/snap/core/10958                    /dev/loop1     squashfs ro,nodev,relatime
├─/snap/snapd/11402                   /dev/loop2     squashfs ro,nodev,relatime
├─/snap/snapd/11588                   /dev/loop3     squashfs ro,nodev,relatime
├─/snap/core/10908                    /dev/loop0     squashfs ro,nodev,relatime
├─/boot                               /dev/nvme0n1p2 ext4     rw,relatime
│ └─/boot/efi                         /dev/nvme0n1p1 vfat     rw,relatime,fmask=0077,dmask
└─/media/raffaele/intdata             /dev/mapper/intdata
                                                     ext4     rw,relatime

Output of df -h

df: /run/user/1000/doc: Operation not permitted
Filesystem                  Size  Used Avail Use% Mounted on
tmpfs                       1.6G  2.1M  1.6G   1% /run
/dev/mapper/vgkubuntu-root  467G  191G  253G  43% /
tmpfs                       7.8G  964K  7.8G   1% /dev/shm
tmpfs                       5.0M  4.0K  5.0M   1% /run/lock
tmpfs                       4.0M     0  4.0M   0% /sys/fs/cgroup
/dev/nvme0n1p2              705M  358M  296M  55% /boot
/dev/nvme0n1p1              511M  7.9M  504M   2% /boot/efi
/dev/mapper/intdata         916G  350G  520G  41% /media/raffaele/intdata
tmpfs                       1.6G   11M  1.6G   1% /run/user/1000
boot

1 Answers

  1. The way this is usually done is with LVM with one large PV (physical volume) with the LUKS encryption layer.

    As long as there is still unpartitioned space on your disk (on this one or another), it should be possible to add more operating systems, in particular other Linux distros.

    Edit: After seeing your partitioning, it appears that all disk space is already taken by that Ubuntu installation.

    There is a guide here how to resize an encrypted partition (but I don't know how up-to-date that is):

    https://help.ubuntu.com/community/ResizeEncryptedPartitions

    You will probably have to resize:

    • Your root filesystem (resize2fs)
    • The LVM logical volume that your root filesystem is in
    • The LVM physical volume that the LV uses
    • The LUKS layer of that PV

    Then there is the swap space that is also using that PV. The simplest course of action might be to deactivate it in /etc/fstab, use swapoff or reboot, remove it completely (its LVM volume group) and keep a little extra space for it in the PV when you resize that one; and after that, recreate the LV for the swap space, create the swap space (mkswap), re-add it to /etc/fstab.

    That is a lot of resizing and manual stuff where a lot can go wrong. This is not for the faint of heart...

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