efiSysMountPoint = '/boot' is not a mounted partition. Is the path configured correctly?

[kazimierzkrauze]

Hi!

I want to install NixOS in Proxmox vm. As it turned out the installer didn’t partition /boot partition, when I run lsblk I get:

[admin@nixos:~]$ lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda      8:0    0   32G  0 disk
└─sda1   8:1    0   32G  0 part /nix/store
                                /
sr0     11:0    1  3,8G  0 rom

[admin@nixos:~]$

Maybe it is not a problem, but I can’t rebuild my system, when I run sudo nixos-rebuild switch --flake /home/admin/nixos-configuration#admin I get:

[admin@nixos:~]$ sudo nixos-rebuild switch --flake /home/admin/nixos-configuration#admin
[sudo] password for admin:
building the system configuration...
efiSysMountPoint = '/boot' is not a mounted partition. Is the path configured correctly?
Traceback (most recent call last):
  File "/nix/store/kp86p258ajqv85ri1swq835bl8s2hj9v-systemd-boot/bin/systemd-boot", line 431, in <module>
    main()
    ~~~~^^
  File "/nix/store/kp86p258ajqv85ri1swq835bl8s2hj9v-systemd-boot/bin/systemd-boot", line 411, in main
    run([CHECK_MOUNTPOINTS])
    ~~~^^^^^^^^^^^^^^^^^^^^^
  File "/nix/store/kp86p258ajqv85ri1swq835bl8s2hj9v-systemd-boot/bin/systemd-boot", line 58, in run
    return subprocess.run(cmd, check=True, text=True, stdout=stdout)
           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/nix/store/sd81bvmch7njdpwx3lkjslixcbj5mivz-python3-3.13.4/lib/python3.13/subprocess.py", line 577, in run
    raise CalledProcessError(retcode, process.args,
                             output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['/nix/store/zlallhh83r4wq5fkaqkv5swbdhxbp7a9-check-mountpoints']' returned non-zero exit status 1.
Failed to install bootloader
Command '['systemd-run', '-E', 'LOCALE_ARCHIVE', '-E', 'NIXOS_INSTALL_BOOTLOADER', '--collect', '--no-ask-password', '--pipe', '--quiet', '--service-type=exec', '--unit=nixos-rebuild-switch-to-configuration', PosixPath('/nix/store/c3iazffxm02rb0xn1pkziw8b88fvlj4y-nixos-system-nixos-25.11.20250630.3016b4b/bin/switch-to-configuration'), 'switch']' returned non-zero exit status 1.

[admin@nixos:~]$

I found these threads:

efiSysMountPoint = '/boot' is not a mounted partition

Hello I try to install nixos on my desktop PC (along existing Ubuntu and Windows 10). I prepared three partitions “nix-root”, “@home” (identical to the Ubuntu home partition) and “nix-log” and mounted all of them in the correct tree into the /mnt directory of the RAM based console installer, including the EFI partition (to nix-root/boot). When I try to install, I get the following error at the end: efiSysMountPoint = ‘/boot’ is not a mounted partition Which is strange for me, as the boot fo…

/boot partition not mounted

I prepared a boot partition and a root partition on a new drive, and installed NixOS from another running NixOS using nixos-install --root /mnt. It boots fine but running e.g. nixos-rebuild results in errors about missing boot partition ➜ ~ sudo nixos-rebuild switch building Nix... building the system configuration... this derivation will be built: /nix/store/fi0z5rs7njgrx1l6hzmji6jdsryf1ng0-nixos-system-leon-nixos-24.05.4169.797f7dc49e0b.drv building '/nix/store/fi0z5rs7njgrx1l6hzmji6jdsry…

But they seem to refer to installing NixOS, I just want to rebuild it.

Can you help me out?

Best,
Miro

[ElvishJerricco]

You’ll need to share your configuration. But it sounds like you installed the system with grub (which doesn’t need a /boot partition) and have switched the configuration to use systemd-boot. But systemd-boot does require a /boot partition and also requires UEFI.

[kazimierzkrauze]

Thank you! That was it, I changed to grub boot and it worked!