Bcachefs - Revision history

Onny: /* Automatically mount encrypted device on boot */ Simplify and modernize

2026-08-12T15:20:55Z

Automatically mount encrypted device on boot: Simplify and modernize

← Older revision		Revision as of 15:20, 12 August 2026
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	=== Automatically mount encrypted device on boot ===		=== Automatically mount encrypted device on boot ===
	Since the Bcachefs mount options do [https://github.com/koverstreet/bcachefs-tools/pull/266 not support supplying a key file yet], we could use the <code>bcachefs</code> command and run it on boot using a [[Systemd]] unit:<syntaxhighlight lang="nix">		Since the Bcachefs mount options do [https://github.com/koverstreet/bcachefs-tools/pull/266 not support supplying a key file yet], we could use the <code>bcachefs unlock</code> command and run it on boot using a [[Systemd]] unit:<syntaxhighlight lang="nix">fileSystems."/mnt" = {
	~~systemd.services~~."~~bcachefs-mount~~" = {		device = "/dev/disk/by-uuid/3c0d7d93-3293-49a3-842e-d9ef77576d97";
	~~after~~ = [ "~~local~~-~~fs.target" ];~~		fsType = "bcachefs";
	~~wantedBy = [ "multi~~-~~user.target~~" ];		options = [ "nofail" ];
	~~environment = {~~		};
	~~DEVICE_PATH~~ = "~~/dev/sda1";~~
	~~MOUNT_POINT =~~ "~~/mnt";~~
	};
	~~script~~ = ''
	~~#!${pkgs.runtimeShell} -e~~

	~~${pkgs.keyutils}/bin/keyctl link @u @s~~

	~~# Check if the device path exists~~
	if [ ~~! -b~~ "~~$DEVICE_PATH~~" ]; ~~then~~
	~~echo "Error: Device path $DEVICE_PATH does not exist."~~
	~~exit 1~~
	fi

	~~# Check if the drive is already mounted~~
	~~if ${pkgs.util-linux~~}~~/bin/mountpoint -q "$MOUNT_POINT"~~; ~~then~~
	~~echo "Drive already mounted at $MOUNT_POINT. Skipping..."~~
	~~exit 0~~
	fi

	# ~~Wait for~~ the ~~device to become available~~		# Ensure to match the correct systemd unit name which gets created by NixOS
	~~while~~ [ ! -~~b "$DEVICE_PATH~~" ]; do		# in the first place. We override the script part.
	~~echo~~ "~~Waiting for~~ $~~DEVICE_PATH to become available~~..."		systemd.services."unlock-bcachefs-mnt" = {
	~~sleep 5~~		serviceConfig.LoadCredential = [ "bcachefs-mnt:/etc/secret.key" ];
	~~done~~		script = lib.mkForce ''
			${lib.getExe' pkgs.keyutils "keyctl"} link @u @s
	~~# Mount the device~~		${config.boot.initrd.systemd.package}/bin/systemd-ask-password --credential=bcachefs-mnt --timeout=0 "enter passphrase for /mnt" \| \
	${pkgs.bcachefs-tools}/~~bin~~/~~bcachefs mount~~ -f /~~etc/keyfile_test "$DEVICE_PATH" "$MOUNT_POINT~~"		exec ${lib.getExe pkgs.bcachefs-tools} unlock \
			"/dev/disk/by-uuid/3c0d7d93-3293-49a3-842e-d9ef77576d97"
	'';		'';
	~~serviceConfig = {~~		};</syntaxhighlight>This example unit unlocks the Bcachefs encrypted partition <code>/dev/disk/by-uuid/3c0d7d93-3293-49a3-842e-d9ef77576d97</code> whereas the fstab entry mounts it to the target <code>/mnt</code> by using the key file <code>/etc/secret.key</code>. Ensure that you replace all disk uuid and target file path occurences.
	~~Type = "oneshot";~~
	~~User = "root";~~
	};
	};
	</syntaxhighlight>This example unit ~~mounts~~ the Bcachefs encrypted partition <code>/dev/~~sda1~~</code> to the target <code>/mnt</code> by using the key file <code>/etc/~~keyfile_test~~</code>.
	[[Category:Filesystem]]		[[Category:Filesystem]]

Onny: Update bcachefs tool parameter to new version

2026-08-12T08:51:15Z

Update bcachefs tool parameter to new version

← Older revision		Revision as of 08:51, 12 August 2026
Line 36:		Line 36:

	<syntaxhighlight lang="console">		<syntaxhighlight lang="console">
	# bcachefs format --~~encrypt~~ /dev/sda		# bcachefs format --encrypted /dev/sda
	# bcachefs unlock /dev/sda		# bcachefs unlock /dev/sda
	# mount -t bcachefs /dev/sda /mnt		# mount -t bcachefs /dev/sda /mnt

Onny: /* NixOS installation on bcachefs */ Cleanup instruction

2025-12-09T13:27:47Z

NixOS installation on bcachefs: Cleanup instruction

← Older revision		Revision as of 13:27, 9 December 2025
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	<syntaxhighlight lang="console">		<syntaxhighlight lang="console">
	# mkfs.fat -F 32 -n boot /dev/sda1		# mkfs.fat -F 32 -n boot /dev/sda1
	~~# nix-shell -p bcachefs-tools~~
	# mkfs.bcachefs -L nixos /dev/sda2		# mkfs.bcachefs -L nixos /dev/sda2
	</syntaxhighlight>		</syntaxhighlight>
Line 174:		Line 173:

	<syntaxhighlight lang="console">		<syntaxhighlight lang="console">
	# ~~nix-shell -p keyutils --run '~~keyctl link @u @s'		# keyctl link @u @s
	# ~~nix-shell~~ -~~p bcachefs~~-~~tools~~		# bcachefs format --label=nixos --encrypted /dev/sda2
	~~# bcachefs format~~ --encrypted /dev/sda2
	# bcachefs unlock /dev/sda2		# bcachefs unlock /dev/sda2
	</syntaxhighlight>		</syntaxhighlight>

	Mount filesystems		Mount filesystems. Use <code>lsblk -o +uuid,fsType \| grep bcachefs</code> to get bcachefs partition uuid.

	~~There are two ways~~ to ~~mount a~~ bcachefs ~~filesystem~~. ~~First, by device:~~

	<syntaxhighlight lang="console">		<syntaxhighlight lang="console">
	# mount /dev/~~sda2~~ /mnt		# mount /dev/disk/by-uuid/<...> /mnt
	# mkdir /mnt/boot		# mkdir /mnt/boot
	# mount /dev/disk/by-label/boot /mnt/boot		# mount /dev/disk/by-label/boot /mnt/boot
	</syntaxhighlight>		</syntaxhighlight>

	~~For better reliability as with any other filesystem, one should mount the filesystem by UUID, by replacing any drive specifiers with it.~~
	~~When you formatted, there was an external UUID shown, but if you lost it, you can retrieve it using~~
	~~<syntaxhighlight lang="console">~~
	~~# lsblk -o +uuid,fsType \| grep bcachefs~~
	~~</syntaxhighlight>~~
	~~And using it like <code>UUID=<UUID></code> in place of <code>/dev/sda1:/dev/sdb1</code> or even just <code>/dev/sda</code>.~~

	Continue installation as recommended by the [https://nixos.org/manual/nixos/stable/index.html#ch-installation NixOS manual].		Continue installation as recommended by the [https://nixos.org/manual/nixos/stable/index.html#ch-installation NixOS manual].

Onny: /* Generate bcachefs enabled installation media */

2025-12-09T13:24:22Z

Generate bcachefs enabled installation media

← Older revision		Revision as of 13:24, 9 December 2025
Line 131:		Line 131:
	"${nixos}/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix"		"${nixos}/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix"
	({ lib, pkgs, ... }: {		({ lib, pkgs, ... }: {
			# Required as a workaround for bug
			# https://github.com/NixOS/nixpkgs/issues/32279
			environment.systemPackages = [ pkgs.keyutils ];
	boot.supportedFilesystems = [ "bcachefs" ];		boot.supportedFilesystems = [ "bcachefs" ];
	})		})

Onny: /* Generate bcachefs enabled installation media */

2025-12-09T13:07:33Z

Generate bcachefs enabled installation media

← Older revision		Revision as of 13:07, 9 December 2025
Line 142:		Line 142:
	The following commands will generate the iso-image which will be available in the directory <code>./result/iso</code>		The following commands will generate the iso-image which will be available in the directory <code>./result/iso</code>

	<syntaxhighlight lang="console">		<syntaxhighlight lang="console"># nix build .#nixosConfigurations.exampleIso.config.system.build.isoImage
	# nix build .#nixosConfigurations.exampleIso.config.system.build.isoImage
	</syntaxhighlight>		</syntaxhighlight>

Onny: /* Tips and tricks */ Add instruction to build bcachefs enabled installation media

2025-12-09T13:06:58Z

Tips and tricks: Add instruction to build bcachefs enabled installation media

← Older revision		Revision as of 13:06, 9 December 2025
Line 113:		Line 113:

	== Tips and tricks ==		== Tips and tricks ==


			=== Generate bcachefs enabled installation media ===

			Use following Nix [[Flakes\|Flake-expression]] to generate a ISO installation image with a bcachefs enabled kernel

			{{file\|flake.nix\|nix\|<nowiki>
			{
			description = "Bcachefs enabled installation media";
			inputs.nixos.url = "nixpkgs/nixos-25.11";

			outputs = { self, nixos }: {
			nixosConfigurations = {
			exampleIso = nixos.lib.nixosSystem {
			system = "x86_64-linux";
			modules = [
			"${nixos}/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix"
			({ lib, pkgs, ... }: {
			boot.supportedFilesystems = [ "bcachefs" ];
			})
			];
			};
			};
			};
			}
			</nowiki>}}

			The following commands will generate the iso-image which will be available in the directory <code>./result/iso</code>

			<syntaxhighlight lang="console">
			# nix build .#nixosConfigurations.exampleIso.config.system.build.isoImage
			</syntaxhighlight>

	=== NixOS installation on bcachefs ===		=== NixOS installation on bcachefs ===

Onny: /* NixOS installation on bcachefs */ Fix correct command usage

2025-12-09T13:04:38Z

NixOS installation on bcachefs: Fix correct command usage

← Older revision		Revision as of 13:04, 9 December 2025
Line 133:		Line 133:
	<syntaxhighlight lang="console">		<syntaxhighlight lang="console">
	# mkfs.fat -F 32 -n boot /dev/sda1		# mkfs.fat -F 32 -n boot /dev/sda1
	# nix shell -p bcachefs-tools		# nix-shell -p bcachefs-tools
	# mkfs.bcachefs -L nixos /dev/sda2		# mkfs.bcachefs -L nixos /dev/sda2
	</syntaxhighlight>		</syntaxhighlight>

Console4852: github issue referenced in wiki is now fixed, so remove note.

2025-09-30T06:51:42Z

github issue referenced in wiki is now fixed, so remove note.

← Older revision		Revision as of 06:51, 30 September 2025
Line 162:		Line 162:
	</syntaxhighlight>		</syntaxhighlight>
	And using it like <code>UUID=<UUID></code> in place of <code>/dev/sda1:/dev/sdb1</code> or even just <code>/dev/sda</code>.		And using it like <code>UUID=<UUID></code> in place of <code>/dev/sda1:/dev/sdb1</code> or even just <code>/dev/sda</code>.

	Note: this is currently broken as per this [https://github.com/NixOS/nixpkgs/issues/317901 github issue]. As a workaround, use `/dev/disk/by-uuid/<UUID>` or `/dev/disk/by-id` instead. This seems to work for single device systems atleast, although atleast at the time of this writing I could not get it to work on my 4+ device raid system.

	Continue installation as recommended by the [https://nixos.org/manual/nixos/stable/index.html#ch-installation NixOS manual].		Continue installation as recommended by the [https://nixos.org/manual/nixos/stable/index.html#ch-installation NixOS manual].

Kiri: added missing newline escape to shell command examples

2025-06-04T03:27:57Z

added missing newline escape to shell command examples

← Older revision		Revision as of 03:27, 4 June 2025
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	--label=hdd.hdd3 /dev/sde \		--label=hdd.hdd3 /dev/sde \
	--label=ssd.ssd1 /dev/sdf \		--label=ssd.ssd1 /dev/sdf \
	--label=ssd.ssd2 /dev/sdg		--label=ssd.ssd2 /dev/sdg \
	--foreground_target=ssd \		--foreground_target=ssd \
	--promote_target=ssd \		--promote_target=ssd \
Line 71:		Line 71:
	--label=hdd.hdd3 /dev/sde \		--label=hdd.hdd3 /dev/sde \
	--label=ssd.ssd1 /dev/sdf \		--label=ssd.ssd1 /dev/sdf \
	--label=ssd.ssd2 /dev/sdg		--label=ssd.ssd2 /dev/sdg \
	--foreground_target=ssd \		--foreground_target=ssd \
	--promote_target=ssd \		--promote_target=ssd \

Onny: Update page for NixOS 25.05. Release contains a kernel with bcachefs now

2025-05-31T14:56:15Z

Update page for NixOS 25.05. Release contains a kernel with bcachefs now

@@ Line 113: / Line 113: @@
 == Tips and tricks ==
 === NixOS installation on bcachefs ===
@@ Line 166: / Line 133: @@
 <syntaxhighlight lang="console">
 # mkfs.fat -F 32 -n boot /dev/sda1
 # mkfs.bcachefs -L nixos /dev/sda2
 </syntaxhighlight>
@@ Line 173: / Line 141: @@
 <syntaxhighlight lang="console">
 # nix-shell -p keyutils --run 'keyctl link @u @s'
 # bcachefs format --encrypted /dev/sda2
 # bcachefs unlock /dev/sda2
@@ Line 197: / Line 166: @@
 Continue installation as recommended by the [https://nixos.org/manual/nixos/stable/index.html#ch-installation NixOS manual].
 === Remote encrypted disk unlocking ===