diff --git a/README.md b/README.md
index 15cc5fbc..dec0a198 100644
--- a/README.md
+++ b/README.md
@@ -3,9 +3,9 @@ Voidvault
 
 Last tested | ISO                                                             | Result
 ----------- | --------------------------------------------------------------- | ------
-2018-12-01  | [void-live-x86_64-20181111.iso][void-live-iso-x86_64-glibc]     | PASS
-2018-12-01  | [void-live-x86_64-musl-20181111.iso][void-live-iso-x86_64-musl] | PASS
-2018-12-01  | [void-live-i686-20181111.iso][void-live-iso-i686-glibc]         | PASS
+2019-01-12  | [void-live-x86_64-20181111.iso][void-live-iso-x86_64-glibc]     | PASS
+2019-01-12  | [void-live-x86_64-musl-20181111.iso][void-live-iso-x86_64-musl] | FAIL
+2019-01-12  | [void-live-i686-20181111.iso][void-live-iso-i686-glibc]         | PASS
 
 
 Bootstrap Void with FDE
@@ -16,7 +16,7 @@ Description
 
 ### Overview
 
-Voidvault bootstraps Void with whole system Btrfs on LUKS.
+Voidvault bootstraps Void with whole system NILFS+LVM on LUKS.
 
 Voidvault works on Void with Intel or AMD x86 CPU. It assumes you are
 comfortable working on the cmdline, and that you have no need for booting
@@ -27,7 +27,7 @@ could cause catastrophic data loss and system instability.
 
 ### Features
 
-- whole system Btrfs on LUKS, including encrypted `/boot`
+- whole system [NILFS][NILFS]+LVM on LUKS, including encrypted `/boot`
 - [runit][runit] PID 1
 - [GPT][GPT] partitioning
 - no swap partition, uses [zram][zram] via [zramen][zramen]
@@ -68,6 +68,7 @@ could cause catastrophic data loss and system instability.
 - uses mq-deadline I/O scheduler for SSDs, BFQ for HDDs (see:
   [resources/etc/udev/rules.d/60-io-schedulers.rules](resources/etc/udev/rules.d/60-io-schedulers.rules))
 - enables runit service for dnscrypt-proxy, nftables and socklog
+- configures [nilfs_cleanerd][nilfs_cleanerd] to reduce overhead
 - configures [Xorg][Xorg], but does not install any Xorg packages (see:
   [resources/etc/X11](resources/etc/X11))
 - optionally disables IPv6, and makes IPv4-only adjustments to dhcpcd,
@@ -77,27 +78,23 @@ could cause catastrophic data loss and system instability.
 
 - `/dev/sdX1` is the BIOS boot sector (size: 2MB)
 - `/dev/sdX2` is the EFI system partition (size: [550MB][550MB])
-- `/dev/sdX3` is the root Btrfs filesystem on LUKS (size: remainder)
-
-Voidvault creates the following Btrfs subvolumes with a [flat layout][flat
-layout]:
-
-Subvolume name       | Mounting point
----                  | ---
-`@`                  | `/`
-`@boot`              | `/boot`
-`@home`              | `/home`
-`@opt`               | `/opt`
-`@srv`               | `/srv`
-`@var`               | `/var`
-`@var-cache-xbps`    | `/var/cache/xbps`
-`@var-log`           | `/var/log`
-`@var-opt`           | `/var/opt`
-`@var-spool`         | `/var/spool`
-`@var-tmp`           | `/var/tmp`
-
-Voidvault [disables Btrfs CoW][disables Btrfs CoW] on `/home`, `/srv`,
-`/var/log`, `/var/spool` and `/var/tmp`.
+- `/dev/sdX3` is the root NILFS+LVM filesystem on LUKS (size: remainder)
+
+Voidvault creates the following LVM logical volumes:
+
+Logical Volume name | Mounting point    | Sizing
+---                 | ---               | ---
+`root`              | `/`               | `7G`
+`boot`              | `/boot`           | `700M`
+`opt`               | `/opt`            | `200M`
+`srv`               | `/srv`            | `200M`
+`var`               | `/var`            | `1G`
+`var-cache-xbps`    | `/var/cache/xbps` | `2G`
+`var-log`           | `/var/log`        | `200M`
+`var-opt`           | `/var/opt`        | `200M`
+`var-spool`         | `/var/spool`      | `200M`
+`var-tmp`           | `/var/tmp`        | `800M`
+`home`              | `/home`           | `100%FREE`
 
 Voidvault mounts directories `/srv`, `/tmp`, `/var/log`, `/var/spool`
 and `/var/tmp` with options `nodev,noexec,nosuid`.
@@ -143,6 +140,7 @@ VOIDVAULT_ROOT_PASS="your root password"
 VOIDVAULT_ROOT_PASS_HASH='$6$rounds=700000$xDn3UJKNvfOxJ1Ds$YEaaBAvQQgVdtV7jFfVnwmh57Do1awMh8vTBtI1higrZMAXUisX2XKuYbdTcxgQMleWZvK3zkSJQ4F3Jyd5Ln1'
 VOIDVAULT_VAULT_NAME="vault"
 VOIDVAULT_VAULT_PASS="your LUKS encrypted volume's password"
+VOIDVAULT_POOL_NAME="vg0"
 VOIDVAULT_HOSTNAME="vault"
 VOIDVAULT_PARTITION="/dev/sdb"
 VOIDVAULT_PROCESSOR="other"
@@ -171,6 +169,7 @@ voidvault --admin-name="live"                                  \
           --root-pass="your root password"                     \
           --vault-name="vault"                                 \
           --vault-pass="your LUKS encrypted volume's password" \
+          --pool-name="vg0"                                    \
           --hostname="vault"                                   \
           --partition="/dev/sdb"                               \
           --processor="other"                                  \
@@ -240,14 +239,6 @@ voidvault ls partitions
 voidvault ls timezones
 ```
 
-### `voidvault disable-cow`
-
-Disable the Copy-on-Write attribute for Btrfs directories.
-
-```sh
-voidvault -r disable-cow dest/
-```
-
 
 Installation
 ------------
@@ -260,7 +251,6 @@ Dependencies
 
 Name                 | Provides                                           | Included in Void ISO¹²?
 ---                  | ---                                                | ---
-btrfs-progs          | Btrfs support                                      | Y
 coreutils            | `chmod`, `chown`, `cp`, `rm`                       | Y
 cryptsetup           | FDE with LUKS                                      | Y
 dosfstools           | create VFAT filesystem for UEFI with `mkfs.vfat`   | Y
@@ -273,7 +263,9 @@ grub                 | FDE on `/boot`, `grub-mkpasswd-pbkdf2`             | Y
 kbd                  | keymap data in `/usr/share/kbd/keymaps`, `setfont` | Y
 kmod                 | `modprobe`                                         | Y
 libressl             | user password salts                                | Y
+lvm2                 | LVM disk partitioning                              | N
 musl³                | libcrypt                                           | Y
+nilfs-utils          | NILFS support                                      | N
 procps-ng            | `pkill`                                            | Y
 rakudo               | `voidvault` Perl 6 runtime                         | N
 tzdata               | timezone data in `/usr/share/zoneinfo/zone.tab`    | Y
@@ -310,6 +302,7 @@ variable values for all configuration options aside from:
 - `--guest-pass`
 - `--hostname`
 - `--ignore-conf-repos`
+- `--pool-name`
 - `--repository`
 - `--root-pass-hash`
 - `--root-pass`
@@ -345,13 +338,13 @@ information, see http://unlicense.org/ or the accompanying UNLICENSE file.
 
 [550MB]: https://wiki.archlinux.org/index.php/EFI_system_partition#Create_the_partition
 [denies console login as root]: https://wiki.archlinux.org/index.php/Security#Denying_console_login_as_root
-[disables Btrfs CoW]: https://wiki.archlinux.org/index.php/Btrfs#Disabling_CoW
 [dnscrypt-proxy]: https://wiki.archlinux.org/index.php/DNSCrypt
-[flat layout]: https://btrfs.wiki.kernel.org/index.php/SysadminGuide#Layout
 [GPT]: https://wiki.archlinux.org/index.php/Partitioning#GUID_Partition_Table
 [GRUB]: https://wiki.archlinux.org/index.php/GRUB
 [hides process information]: https://wiki.archlinux.org/index.php/Security#hidepid
 [nftables]: https://wiki.archlinux.org/index.php/nftables
+[NILFS]: https://nilfs.sourceforge.io/
+[nilfs_cleanerd]: https://news.ycombinator.com/item?id=18753858
 [OpenSSH]: https://wiki.archlinux.org/index.php/Secure_Shell
 [runit]: https://wiki.voidlinux.org/runit
 [Sysctl]: https://wiki.archlinux.org/index.php/Sysctl
diff --git a/bin/voidvault b/bin/voidvault
index faa05d96..5daba236 100755
--- a/bin/voidvault
+++ b/bin/voidvault
@@ -10,33 +10,6 @@ use Voidvault::Utils;
 
 
 
-# -----------------------------------------------------------------------------
-# disable-cow
-# -----------------------------------------------------------------------------
-
-multi sub MAIN(
-    'disable-cow',
-    Bool :c(:$clean),
-    Str :g(:$group),
-    Str :p(:$permissions),
-    Bool :r(:$recursive),
-    Str :u(:$user),
-    *@directory
-    --> Nil
-)
-{
-    my %opts;
-    %opts<clean> = $clean if $clean;
-    %opts<group> = $group if $group;
-    %opts<permissions> = $permissions if $permissions;
-    %opts<recursive> = $recursive if $recursive;
-    %opts<user> = $user if $user;
-    Voidvault::Utils.disable-cow(@directory, |%opts);
-}
-
-
-
-
 # -----------------------------------------------------------------------------
 # gen-pass-hash
 # -----------------------------------------------------------------------------
@@ -58,11 +31,6 @@ multi sub MAIN('gen-pass-hash', Bool :g(:$grub) --> Nil)
 # help
 # -----------------------------------------------------------------------------
 
-multi sub MAIN('help', 'disable-cow' --> Nil)
-{
-    USAGE('disable-cow');
-}
-
 multi sub MAIN('help', 'gen-pass-hash' --> Nil)
 {
     USAGE('gen-pass-hash');
@@ -111,6 +79,7 @@ multi sub MAIN(
         Str :keymap($),
         Str :locale($),
         Str :partition($),
+        Str :pool-name($),
         Str :processor($),
         Str :repository($),
         Str :root-pass($),
@@ -182,7 +151,6 @@ multi sub USAGE(--> Nil)
       voidvault <command>
 
     Commands:
-      disable-cow          Disable copy-on-write on directories
       gen-pass-hash        Generate password hash
       help                 Show help for subcommands
       ls                   List keymaps, locales, partitions, timezones
@@ -197,35 +165,6 @@ multi sub USAGE(--> Nil)
     say($HELP);
 }
 
-multi sub USAGE('disable-cow' --> Nil)
-{
-    constant $HELP = qq:to/EOF/.trim;
-    Usage:
-      voidvault [--clean]
-                [--permissions=<octal>]
-                [--user=<username>]
-                [--group=<groupname>]
-                disable-cow <directory> [<directory> <directory>..]
-      voidvault [-r] disable-cow <directory> [<directory> <directory>..]
-
-    Options:
-      -c, --clean
-        Remake directories with CoW disabled
-      -r, --recursive
-        Recursively disable CoW on directories
-      -p, --permissions=<octal>
-        Octal file mode bits (defaults to "755")
-      -u, --user=<username>
-        Named user to own file (defaults to "$*USER")
-      -g, --group=<groupname>
-        Named group to own file (defaults to "$*GROUP")
-
-    Positionals:
-      <directory>        Path to directory
-    EOF
-    say($HELP);
-}
-
 multi sub USAGE('gen-pass-hash' --> Nil)
 {
     constant $HELP = q:to/EOF/.trim;
@@ -266,6 +205,7 @@ multi sub USAGE('new' --> Nil)
                 [--grub-name=<username>] [--grub-pass=<password>]
                 [--root-pass=<password>]
                 [--vault-name=<vaultname>] [--vault-pass=<password>]
+                [--pool-name=<poolname>]
                 [--hostname=<hostname>] [--partition=<device>]
                 [--processor=<processor>] [--graphics=<graphics>]
                 [--disk-type=<disktype>] [--locale=<locale>]
@@ -312,6 +252,8 @@ multi sub USAGE('new' --> Nil)
         Locale
       --partition=<device>
         Partition target for install
+      --pool-name=<poolname>
+        Name for LVM volume group
       --processor=<processor>
         Processor type
       --repository=<repository>
diff --git a/doc/guides/btrfs-administration.md b/doc/guides/btrfs-administration.md
deleted file mode 100644
index 18a15303..00000000
--- a/doc/guides/btrfs-administration.md
+++ /dev/null
@@ -1,181 +0,0 @@
-# Btrfs Administration
-
-## Setup
-
-```sh
-# create base directories
-mkdir -p /opt/{snapshots,subvolumes}
-chmod 700 /opt/{snapshots,subvolumes}
-
-# create example-alpha subvolume
-btrfs subvolume create /opt/subvolumes/example-alpha
-
-# mount example-alpha subvolume
-_mount_opts+="compress=lzo,"
-_mount_opts+="noatime,"
-_mount_opts+="nodiratime,"
-_mount_opts+="rw,"
-_mount_opts+="space_cache,"
-_mount_opts+="ssd,"
-_mount_opts+="subvol=@opt/subvolumes/example-alpha"
-mount -t btrfs -o "$_mount_opts" /dev/mapper/vault /home/admin/.example-alpha
-chown -R admin:admin /home/admin/.example-alpha
-
-# add example-alpha subvolume mount to fstab
-genfstab -U -p / | vipe
-```
-
-## Backup subvolumes
-
-```sh
-# create read-only snapshot of example-alpha at time A
-_snaptime_a="$(date '+%FT%H:%M')"
-mkdir -p "/opt/snapshots/$_snaptime_a"
-btrfs subvolume snapshot -r /opt/subvolumes/example-alpha "/opt/snapshots/$_snaptime_a"
-sync
-
-# create read-only snapshot of example-alpha at time B
-_snaptime_b="$(date '+%FT%H:%M')"
-mkdir -p "/opt/snapshots/$_snaptime_b"
-btrfs subvolume snapshot -r /opt/subvolumes/example-alpha "/opt/snapshots/$_snaptime_b"
-sync
-
-# backup read-only incremental snapshot of example-alpha
-btrfs send -p "/opt/snapshots/$_snaptime_a/example-alpha" "/opt/snapshots/$_snaptime_b/example-alpha"
-```
-
-```sh
-MASTER_INTERFACE="enp4s0f2"
-SLAVE_IPV6="fe80::6497:17de:fee3:1942"
-SLAVE_USER_NAME="admin"
-
-# [master] snapshot example-alpha
-_seconds_since_epoch="$(date --utc '+%s')"
-_snapshot="example-alpha.snapshot.$_seconds_since_epoch"
-btrfs subvolume snapshot -r /opt/subvolumes/example-alpha "/opt/snapshots/$_snapshot"
-sync
-
-# [master] send/receive full example-alpha snapshot
-btrfs send -v "/opt/snapshots/$_snapshot" \
-  | ssh -T -i "/path/to/id_ed25519" \
-      ${SLAVE_USER_NAME}@${SLAVE_IPV6}%${MASTER_INTERFACE} \
-      "btrfs receive /opt/snapshots"
-
-# [master] save full example-alpha snapshot to file for sending
-_snapshot_type="full"
-_snapshot_file="$_snapshot.$_snapshot_type"
-btrfs send -f "$_snapshot_file" "/opt/snapshots/$_snapshot"
-sync
-chown $USER:$USER "$_snapshot_file"
-
-# [master] rsync the full example-alpha snapshot file to slave
-rsync \
-  --dry-run \
-  --recursive \
-  --perms \
-  --times \
-  --partial \
-  --inplace \
-  --verbose \
-  --human-readable \
-  --progress \
-  --itemize-changes \
-  --itemize-changes \
-  --rsh 'ssh -T -i /path/to/id_ed25519' \
-  "$_snapshot_file" \
-  ${SLAVE_USER_NAME}@[${SLAVE_IPV6}]:/home/staged/snapshots/$_snapshot_file
-
-# [slave] receive snapshot from file
-btrfs receive -f "/home/staged/snapshots/$_snapshot_file" /opt/snapshots
-rm "/home/staged/snapshots/$_snapshot_file"
-sync
-
-# [slave] take rw snapshot of ro snapshot
-btrfs subvolume snapshot "/opt/snapshots/$_snapshot" /opt/subvolumes/example-alpha
-sync
-```
-
-```sh
-#!/bin/bash
-
-MASTER_INTERFACE="enp4s0f2"
-SLAVE_IPV6="fe80::6497:17de:fee3:1942"
-SLAVE_USER_NAME="admin"
-
-# send / receive
-ssh -T -i "$HOME/.ssh/box/id_ed25519" \
-  ${SLAVE_USER_NAME}@${SLAVE_IPV6}%${MASTER_INTERFACE} \
-  "btrfs send /opt/snapshots/$_snapshot" \
-    | btrfs receive -v /opt/snapshots
-
-# incremental send / receive
-ssh -T -i "$HOME/.ssh/box/id_ed25519" \
-  ${SLAVE_USER_NAME}@${SLAVE_IPV6}%${MASTER_INTERFACE} \
-  "btrfs send -p /opt/snapshots/$_snapshot_parent /opt/snapshots/$_snapshot" \
-      | btrfs receive -v /opt/snapshots
-
-# syncing file
-rsync \
-  --dry-run \
-  --recursive \
-  --perms \
-  --times \
-  --partial \
-  --inplace \
-  --verbose \
-  --human-readable \
-  --progress \
-  --itemize-changes \
-  --itemize-changes \
-  --rsh "ssh -T -i \"$HOME/.ssh/box/id_ed25519\"" \
-  ${SLAVE_USER_NAME}@[${SLAVE_IPV6}%${MASTER_INTERFACE}]:/home/${SLAVE_USER_NAME}/${_snapshot_file} \
-  "$HOME"
-```
-
-## Refresh snapshots
-
-```sh
-#!/bin/bash
-
-# delete existing snapshots
-# btrfs subvolume list /
-# btrfs subvolume delete /opt/snapshots/...
-
-_seconds_since_epoch="$(date --utc '+%s')"
-# refresh snapshots
-for _name in example-alpha \
-             example-bravo; do
-  _snapshot="$_name.snapshot.$_seconds_since_epoch"
-  sudo btrfs subvolume snapshot -r "/opt/subvolumes/$_name" "/opt/snapshots/$_snapshot"
-done
-sudo sync
-```
-
-## Restore from snapshot
-
-For when you have accidentally deleted `~/.example-alpha/important-file`.
-
-```sh
-# unmount ~/.example-alpha
-umount ~/.example-alpha
-
-# delete example-alpha subvolume
-btrfs subvolume delete /opt/subvolumes/example-alpha
-
-# take rw snapshot of most recent example-alpha snapshot
-btrfs subvolume snapshot "/opt/snapshots/example-alpha.snapshot.1476147345" /opt/subvolumes/example-alpha
-
-# retrieve subvolume ID of newly created example-alpha subvolume
-btrfs subvolume list /
-_NEW_ID=701
-
-# the `mount` command, run as root, needs the absolute path to your `~`
-_HOME="$HOME"
-
-# mount this new snapshot as example-alpha at ~/.example-alpha
-# /dev/mapper/vault is root
-mount -t btrfs -o rw,nodatacow,noatime,nodiratime,compress=lzo,ssd,space_cache,subvolid=$_NEW_ID,subvol=/@opt/subvolumes/example-alpha /dev/mapper/vault "$_HOME/.example-alpha"
-
-# update fstab (with `subvolid=$_NEW_ID`)
-genfstab -U /
-```
diff --git a/doc/guides/nilfs-lvm-administration.md b/doc/guides/nilfs-lvm-administration.md
new file mode 100644
index 00000000..a33df717
--- /dev/null
+++ b/doc/guides/nilfs-lvm-administration.md
@@ -0,0 +1,126 @@
+# NILFS+LVM Administration
+
+## Create and mount new LVM logical volume
+
+```sh
+# create lvm logical volume
+lvcreate --name sandbox --extents 100%FREE vg0
+
+# activate lvm logical volume
+vgchange --activate y
+
+# format lvm logical volume
+mkfs.nilfs2 -L sandbox /dev/vg0/sandbox
+
+# mount lvm logical volume
+mkdir /path/to/sandbox
+_mount_opts='rw,lazytime'
+mount \
+  --types nilfs2 \
+  --options "$_mount_opts" \
+  /dev/vg0/sandbox \
+  /path/to/sandbox
+
+# add lvm logical volume mount to fstab (may require reboot to obtain UUID)
+_uuid="$(blkid --match-tag UUID --output value /dev/vg0/sandbox)"
+cat >> /etc/fstab <<"EOF"
+# /dev/vg0/sandbox LABEL=sandbox
+UUID=$_uuid /path/to/sandbox nilfs2 $_mount_opts 0 0
+EOF
+```
+
+## Resize LVM logical volume
+
+Shrink:
+
+```sh
+# shrink NILFS to under target size
+nilfs-resize /dev/vg0/srv 430M
+# resize logical volume to target size
+lvresize --size 500M vg0/srv
+# grow NILFS without dimension to occupy all logical volume free space
+nilfs-resize /dev/vg0/srv
+```
+
+Grow:
+
+```sh
+# resize logical volume to target size
+lvresize --size +2G vg0/srv
+# grow NILFS without dimension to occupy all logical volume free space
+nilfs-resize /dev/vg0/srv
+```
+
+Shrink and grow operations must be carried out on live, mounted NILFS
+filesystems. They won't work otherwise.
+
+## Restore LVM logical volume from NILFS snapshot
+
+Take NILFS snapshot:
+
+```sh
+mkcp --snapshot /dev/vg0/sandbox
+```
+
+Create and mount logical volume for holding data restored from NILFS
+snapshot:
+
+```sh
+lvcreate --name restore --extents 100%FREE vg0
+vgchange --activate y
+mkfs.nilfs2 -L restore /dev/vg0/restore
+mkdir /path/to/restore
+mount \
+  --types nilfs2 \
+  --options 'rw,lazytime' \
+  /dev/vg0/restore \
+  /path/to/restore
+```
+
+Mount NILFS snapshot:
+
+```sh
+mkdir /path/to/staging
+# must mount snapshot read-only
+mount \
+  --types nilfs2 \
+  --options 'cp=7,ro,lazytime' \
+  /dev/vg0/sandbox \
+  /path/to/staging
+```
+
+Conserve disk space by `rm -rf`ing the original contents after staging
+contains read-only mount of snapshot. Do not destroy the original
+filesystem (yet).
+
+Copy snapshotted contents:
+
+```sh
+rsync \
+  --recursive \
+  --perms \
+  --times \
+  --partial \
+  --inplace \
+  --verbose \
+  --human-readable \
+  --progress \
+  --itemize-changes \
+  --itemize-changes \
+  /path/to/staging/ \
+  /path/to/restore
+```
+
+Unmount staging:
+
+```
+umount /path/to/staging
+```
+
+Securely delete original LVM logical volume:
+
+```sh
+umount /path/to/sandbox
+shred -fvz -n 7 /dev/vg0/sandbox
+lvremove vg0/sandbox
+```
diff --git a/examples/new-from-cli-passhash.sh b/examples/new-from-cli-passhash.sh
index a1ad268a..147546bd 100755
--- a/examples/new-from-cli-passhash.sh
+++ b/examples/new-from-cli-passhash.sh
@@ -14,6 +14,7 @@ voidvault --admin-name='live'
           --root-pass-hash='$6$rounds=700000$xDn3UJKNvfOxJ1Ds$YEaaBAvQQgVdtV7jFfVnwmh57Do1awMh8vTBtI1higrZMAXUisX2XKuYbdTcxgQMleWZvK3zkSJQ4F3Jyd5Ln1'                                                                                                                                                                                                                                                                                                                   \
           --vault-name='vault'                                                                                                                                                                                                                                                                                                                                                                                                                                          \
           --vault-pass='xyzzy'                                                                                                                                                                                                                                                                                                                                                                                                                                          \
+          --pool-name='vg0'                                                                                                                                                                                                                                                                                                                                                                                                                                             \
           --hostname='vault'                                                                                                                                                                                                                                                                                                                                                                                                                                            \
           --partition='/dev/sda'                                                                                                                                                                                                                                                                                                                                                                                                                                        \
           --processor='intel'                                                                                                                                                                                                                                                                                                                                                                                                                                           \
diff --git a/examples/new-from-cli.sh b/examples/new-from-cli.sh
index 4b5ff7f6..4778815a 100755
--- a/examples/new-from-cli.sh
+++ b/examples/new-from-cli.sh
@@ -13,6 +13,7 @@ voidvault --admin-name="live"                                  \
           --root-pass="your root password"                     \
           --vault-name="vault"                                 \
           --vault-pass="your LUKS encrypted volume's password" \
+          --pool-name="vg0"                                    \
           --hostname="vault"                                   \
           --partition="/dev/sdb"                               \
           --processor="other"                                  \
diff --git a/examples/new-from-env-vars-passhash.sh b/examples/new-from-env-vars-passhash.sh
index 86299166..725a4845 100755
--- a/examples/new-from-env-vars-passhash.sh
+++ b/examples/new-from-env-vars-passhash.sh
@@ -14,6 +14,7 @@ export VOIDVAULT_GRUB_PASS_HASH='grub.pbkdf2.sha512.25000.4A7BC4FE022FA7E7D32B0B
 export VOIDVAULT_ROOT_PASS_HASH='$6$rounds=700000$xDn3UJKNvfOxJ1Ds$YEaaBAvQQgVdtV7jFfVnwmh57Do1awMh8vTBtI1higrZMAXUisX2XKuYbdTcxgQMleWZvK3zkSJQ4F3Jyd5Ln1'
 export VOIDVAULT_VAULT_NAME='vault'
 export VOIDVAULT_VAULT_PASS='xyzzy'
+export VOIDVAULT_POOL_NAME='vg0'
 export VOIDVAULT_HOSTNAME='vault'
 export VOIDVAULT_PARTITION='/dev/sda'
 export VOIDVAULT_PROCESSOR='intel'
diff --git a/examples/new-from-env-vars.sh b/examples/new-from-env-vars.sh
index 95bc77d7..79cfeabd 100755
--- a/examples/new-from-env-vars.sh
+++ b/examples/new-from-env-vars.sh
@@ -13,6 +13,7 @@ export VOIDVAULT_GRUB_PASS="your grub user's password"
 export VOIDVAULT_ROOT_PASS="your root password"
 export VOIDVAULT_VAULT_NAME="vault"
 export VOIDVAULT_VAULT_PASS="your LUKS encrypted volume's password"
+export VOIDVAULT_POOL_NAME="vg0"
 export VOIDVAULT_HOSTNAME="vault"
 export VOIDVAULT_PARTITION="/dev/sdb"
 export VOIDVAULT_PROCESSOR="other"
diff --git a/lib/Voidvault.pm6 b/lib/Voidvault.pm6
index e2e6ee02..fcc8a3b4 100644
--- a/lib/Voidvault.pm6
+++ b/lib/Voidvault.pm6
@@ -25,6 +25,7 @@ method new(
         Str :keymap($),
         Str :locale($),
         Str :partition($),
+        Str :pool-name($),
         Str :processor($),
         Str :repository($),
         Str :root-pass($),
diff --git a/lib/Voidvault/Bootstrap.pm6 b/lib/Voidvault/Bootstrap.pm6
index 52faa82e..af7ada0f 100644
--- a/lib/Voidvault/Bootstrap.pm6
+++ b/lib/Voidvault/Bootstrap.pm6
@@ -45,6 +45,7 @@ method bootstrap(::?CLASS:D: --> Nil)
     self!install-bootloader;
     self!configure-sysctl;
     self!configure-nftables;
+    self!configure-nilfs;
     self!configure-openssh;
     self!configure-udev;
     self!configure-hidepid;
@@ -70,7 +71,6 @@ method !setup(--> Nil)
 
     # fetch dependencies needed prior to voidstrap
     my Str:D @dep = qw<
-        btrfs-progs
         coreutils
         cryptsetup
         dialog
@@ -82,7 +82,10 @@ method !setup(--> Nil)
         grub
         kbd
         kmod
+        libnilfs
         libressl
+        lvm2
+        nilfs-utils
         procps-ng
         tzdata
         util-linux
@@ -163,8 +166,8 @@ multi sub build-xbps-install-dep-cmdline(
 # secure disk configuration
 method !mkdisk(--> Nil)
 {
-    my DiskType:D $disk-type = $.config.disk-type;
     my Str:D $partition = $.config.partition;
+    my PoolName:D $pool-name = $.config.pool-name;
     my VaultName:D $vault-name = $.config.vault-name;
     my VaultPass $vault-pass = $.config.vault-pass;
 
@@ -181,14 +184,11 @@ method !mkdisk(--> Nil)
         Voidvault::Utils.gen-partition('vault', $partition);
     mkvault($partition-vault, $vault-name, :$vault-pass);
 
-    # create and mount btrfs volumes
-    mkbtrfs($disk-type, $vault-name);
+    # create and mount nilfs+lvm
+    mknilfslvm($pool-name, $vault-name);
 
     # mount efi boot
     mount-efi($partition-efi);
-
-    # disable Btrfs CoW
-    disable-cow();
 }
 
 # partition disk with gdisk
@@ -441,38 +441,19 @@ multi sub build-cryptsetup-luks-open-cmdline(
         EOF
 }
 
-# create and mount btrfs volumes on open vault
-sub mkbtrfs(DiskType:D $disk-type, VaultName:D $vault-name --> Nil)
+# create and mount nilfs+lvm structure on open vault
+sub mknilfslvm(PoolName:D $pool-name, VaultName:D $vault-name --> Nil)
 {
-    # create btrfs filesystem on opened vault
-    run(qw<modprobe btrfs>);
-    run(qqw<mkfs.btrfs /dev/mapper/$vault-name>);
-
-    # set mount options
-    my Str:D @mount-options = qw<
-        rw
-        lazytime
-        compress=lzo
-        space_cache
-    >;
-    push(@mount-options, 'ssd') if $disk-type eq 'SSD';
-    my Str:D $mount-options = @mount-options.join(',');
+    # create lvm physical volume (pv) on open vault
+    run(qqw<pvcreate /dev/mapper/$vault-name>);
 
-    # mount main btrfs filesystem on open vault
-    mkdir('/mnt2');
-    run(qqw<
-        mount
-        --types btrfs
-        --options $mount-options
-        /dev/mapper/$vault-name
-        /mnt2
-    >);
+    # create lvm volume group (vg) hosting physical volume
+    run(qqw<vgcreate $pool-name /dev/mapper/$vault-name>);
 
-    # btrfs subvolumes, starting with root / ('')
-    my Str:D @btrfs-dir =
-        '',
+    # logical volume (lv), deliberately custom ordered
+    my Str:D @lv =
+        'root',
         'boot',
-        'home',
         'opt',
         'srv',
         'var',
@@ -480,148 +461,339 @@ sub mkbtrfs(DiskType:D $disk-type, VaultName:D $vault-name --> Nil)
         'var-log',
         'var-opt',
         'var-spool',
-        'var-tmp';
+        'var-tmp',
+        'home';
+
+    # create lvm lvs
+    lvcreate(@lv, $pool-name);
+
+    # activate lvm lvs
+    run(qw<vgchange --activate y>);
+
+    # make nilfs on each lvm lv
+    mknilfs(@lv, $pool-name);
 
-    # create btrfs subvolumes
-    chdir('/mnt2');
-    @btrfs-dir.map(-> Str:D $btrfs-dir {
-        run(qqw<btrfs subvolume create @$btrfs-dir>);
+    # mount nilfs lvm structure
+    mount-nilfslvm(@lv, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D @lv,
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    @lv.map(-> Str:D $lv {
+        lvcreate($lv, $pool-name);
     });
-    chdir('/');
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'root',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # root (C</>) sized at 7G
+    my Str:D $size = '7G';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'boot',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # boot (C</boot>) sized at 700M
+    my Str:D $size = '700M';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'opt',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # opt (C</opt>) sized at 200M
+    my Str:D $size = '200M';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'srv',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # srv (C</srv>) sized at 200M
+    my Str:D $size = '200M';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'var',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # var (C</var>) sized at 1G
+    my Str:D $size = '1G';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'var-cache-xbps',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # var-cache-xbps (C</var/cache/xbps>) sized at 2G
+    my Str:D $size = '2G';
+    lvcreate($lv, :$size, $pool-name);
+}
 
-    # mount btrfs subvolumes
-    @btrfs-dir.map(-> Str:D $btrfs-dir {
-        mount-btrfs-subvolume($btrfs-dir, $mount-options, $vault-name);
+multi sub lvcreate(
+    Str:D $lv where 'var-log',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # var-log (C</var/log>) sized at 200M
+    my Str:D $size = '200M';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'var-opt',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # var-opt (C</var/opt>) sized at 200M
+    my Str:D $size = '200M';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'var-spool',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # var-spool (C</var/spool>) sized at 200M
+    my Str:D $size = '200M';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'var-tmp',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # var-tmp (C</var/tmp>) sized at 800M
+    my Str:D $size = '800M';
+    lvcreate($lv, :$size, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $lv where 'home',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # home (C</home>) sized at 100% of remaining free space in vg
+    my Str:D $extents = '100%FREE';
+    lvcreate($lv, :$extents, $pool-name);
+}
+
+multi sub lvcreate(
+    Str:D $name,
+    PoolName:D $pool-name,
+    Str:D :$extents! where .so
+    --> Nil
+)
+{
+    run(qqw<lvcreate --name $name --extents $extents $pool-name>);
+}
+
+multi sub lvcreate(
+    Str:D $name,
+    PoolName:D $pool-name,
+    Str:D :$size! where .so
+    --> Nil
+)
+{
+    run(qqw<lvcreate --name $name --size $size $pool-name>);
+}
+
+multi sub mknilfs(Str:D @lv, PoolName:D $pool-name --> Nil)
+{
+    run(qw<modprobe nilfs2>);
+    @lv.map(-> Str:D $lv {
+        mknilfs($lv, $pool-name);
     });
+}
+
+multi sub mknilfs(Str:D $lv, PoolName:D $pool-name --> Nil)
+{
+    run(qqw<mkfs.nilfs2 -L $lv /dev/$pool-name/$lv>);
+}
+
+multi sub mount-nilfslvm(
+    Str:D @lv,
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    @lv.map(-> Str:D $lv {
+        mount-nilfslvm($lv, $pool-name);
+    });
+}
+
+multi sub mount-nilfslvm(
+    Str:D $lv where 'root',
+    PoolName:D $pool-name
+    --> Nil
+)
+{
+    # set mount options
+    my Str:D $mount-options = 'rw,lazytime';
 
-    # unmount /mnt2 and remove
-    run(qw<umount /mnt2>);
-    rmdir('/mnt2');
+    # mount nilfs+lvm root on open vault
+    run(qqw<
+        mount
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt
+    >);
 }
 
-multi sub mount-btrfs-subvolume(
-    'srv',
-    Str:D $mount-options,
-    VaultName:D $vault-name
+multi sub mount-nilfslvm(
+    Str:D $lv where 'srv',
+    PoolName:D $pool-name
     --> Nil
 )
 {
-    my Str:D $btrfs-dir = 'srv';
-    mkdir("/mnt/$btrfs-dir");
+    mkdir("/mnt/$lv");
+    my Str:D $mount-options = 'rw,lazytime,nodev,noexec,nosuid';
     run(qqw<
         mount
-        --types btrfs
-        --options $mount-options,nodev,noexec,nosuid,subvol=@$btrfs-dir
-        /dev/mapper/$vault-name
-        /mnt/$btrfs-dir
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt/$lv
     >);
 }
 
-multi sub mount-btrfs-subvolume(
-    'var-cache-xbps',
-    Str:D $mount-options,
-    VaultName:D $vault-name
+multi sub mount-nilfslvm(
+    Str:D $lv where 'var-cache-xbps',
+    PoolName:D $pool-name
     --> Nil
 )
 {
-    my Str:D $btrfs-dir = 'var/cache/xbps';
-    mkdir("/mnt/$btrfs-dir");
+    my Str:D $dir = $lv.subst('-', '/', :g);
+    mkdir("/mnt/$dir");
+    my Str:D $mount-options = 'rw,lazytime';
     run(qqw<
         mount
-        --types btrfs
-        --options $mount-options,subvol=@var-cache-xbps
-        /dev/mapper/$vault-name
-        /mnt/$btrfs-dir
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt/$dir
     >);
 }
 
-multi sub mount-btrfs-subvolume(
-    'var-log',
-    Str:D $mount-options,
-    VaultName:D $vault-name
+multi sub mount-nilfslvm(
+    Str:D $lv where 'var-log',
+    PoolName:D $pool-name
     --> Nil
 )
 {
-    my Str:D $btrfs-dir = 'var/log';
-    mkdir("/mnt/$btrfs-dir");
+    my Str:D $dir = $lv.subst('-', '/', :g);
+    mkdir("/mnt/$dir");
+    my Str:D $mount-options = 'rw,lazytime,nodev,noexec,nosuid';
     run(qqw<
         mount
-        --types btrfs
-        --options $mount-options,nodev,noexec,nosuid,subvol=@var-log
-        /dev/mapper/$vault-name
-        /mnt/$btrfs-dir
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt/$dir
     >);
 }
 
-multi sub mount-btrfs-subvolume(
-    'var-opt',
-    Str:D $mount-options,
-    VaultName:D $vault-name
+multi sub mount-nilfslvm(
+    Str:D $lv where 'var-opt',
+    PoolName:D $pool-name
     --> Nil
 )
 {
-    my Str:D $btrfs-dir = 'var/opt';
-    mkdir("/mnt/$btrfs-dir");
+    my Str:D $dir = $lv.subst('-', '/', :g);
+    mkdir("/mnt/$dir");
+    my Str:D $mount-options = 'rw,lazytime';
     run(qqw<
         mount
-        --types btrfs
-        --options $mount-options,subvol=@var-opt
-        /dev/mapper/$vault-name
-        /mnt/$btrfs-dir
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt/$dir
     >);
 }
 
-multi sub mount-btrfs-subvolume(
-    'var-spool',
-    Str:D $mount-options,
-    VaultName:D $vault-name
+multi sub mount-nilfslvm(
+    Str:D $lv where 'var-spool',
+    PoolName:D $pool-name
     --> Nil
 )
 {
-    my Str:D $btrfs-dir = 'var/spool';
-    mkdir("/mnt/$btrfs-dir");
+    my Str:D $dir = $lv.subst('-', '/', :g);
+    mkdir("/mnt/$dir");
+    my Str:D $mount-options = 'rw,lazytime,nodev,noexec,nosuid';
     run(qqw<
         mount
-        --types btrfs
-        --options $mount-options,nodev,noexec,nosuid,subvol=@var-spool
-        /dev/mapper/$vault-name
-        /mnt/$btrfs-dir
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt/$dir
     >);
 }
 
-multi sub mount-btrfs-subvolume(
-    'var-tmp',
-    Str:D $mount-options,
-    VaultName:D $vault-name
+multi sub mount-nilfslvm(
+    Str:D $lv where 'var-tmp',
+    PoolName:D $pool-name
     --> Nil
 )
 {
-    my Str:D $btrfs-dir = 'var/tmp';
-    mkdir("/mnt/$btrfs-dir");
+    my Str:D $dir = $lv.subst('-', '/', :g);
+    mkdir("/mnt/$dir");
+    my Str:D $mount-options = 'rw,lazytime,nodev,noexec,nosuid';
     run(qqw<
         mount
-        --types btrfs
-        --options $mount-options,nodev,noexec,nosuid,subvol=@var-tmp
-        /dev/mapper/$vault-name
-        /mnt/$btrfs-dir
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt/$dir
     >);
-    run(qqw<chmod 1777 /mnt/$btrfs-dir>);
+    run(qqw<chmod 1777 /mnt/$dir>);
 }
 
-multi sub mount-btrfs-subvolume(
-    Str:D $btrfs-dir,
-    Str:D $mount-options,
-    VaultName:D $vault-name
+multi sub mount-nilfslvm(
+    Str:D $lv,
+    PoolName:D $pool-name
     --> Nil
 )
 {
-    mkdir("/mnt/$btrfs-dir");
+    my Str:D $mount-options = 'rw,lazytime';
+    mkdir("/mnt/$lv");
     run(qqw<
         mount
-        --types btrfs
-        --options $mount-options,subvol=@$btrfs-dir
-        /dev/mapper/$vault-name
-        /mnt/$btrfs-dir
+        --types nilfs2
+        --options $mount-options
+        /dev/$pool-name/$lv
+        /mnt/$lv
     >);
 }
 
@@ -632,18 +804,6 @@ sub mount-efi(Str:D $partition-efi --> Nil)
     run(qqw<mount $partition-efi $efi-dir>);
 }
 
-sub disable-cow(--> Nil)
-{
-    my Str:D @directory = qw<
-        home
-        srv
-        var/log
-        var/spool
-        var/tmp
-    >.map(-> Str:D $directory { sprintf(Q{/mnt/%s}, $directory) });
-    Voidvault::Utils.disable-cow(|@directory, :recursive);
-}
-
 # bootstrap initial chroot with voidstrap
 method !voidstrap-base(--> Nil)
 {
@@ -671,7 +831,6 @@ method !voidstrap-base(--> Nil)
         bash
         bash-completion
         binutils
-        btrfs-progs
         bzip2
         ca-certificates
         cdrtools
@@ -717,6 +876,7 @@ method !voidstrap-base(--> Nil)
         linux-firmware
         linux-firmware-network
         logrotate
+        lvm2
         lynx
         lz4
         man-db
@@ -725,6 +885,7 @@ method !voidstrap-base(--> Nil)
         ncurses-term
         net-tools
         nftables
+        nilfs-utils
         openresolv
         openssh
         pciutils
@@ -1166,10 +1327,18 @@ method !install-bootloader(--> Nil)
     my Str:D $partition = $.config.partition;
     my Str:D $partition-vault =
         Voidvault::Utils.gen-partition('vault', $partition);
+    my PoolName:D $pool-name = $.config.pool-name;
     my UserName:D $user-name-grub = $.config.user-name-grub;
     my Str:D $user-pass-hash-grub = $.config.user-pass-hash-grub;
     my VaultName:D $vault-name = $.config.vault-name;
-    replace('grub', $disable-ipv6, $graphics, $partition-vault, $vault-name);
+    replace(
+        'grub',
+        $disable-ipv6,
+        $graphics,
+        $partition-vault,
+        $pool-name,
+        $vault-name
+    );
     replace('10_linux');
     configure-bootloader('superusers', $user-name-grub, $user-pass-hash-grub);
     install-bootloader($partition);
@@ -1301,6 +1470,11 @@ method !configure-nftables(--> Nil)
     });
 }
 
+method !configure-nilfs(--> Nil)
+{
+    replace('nilfs_cleanerd.conf');
+}
+
 method !configure-openssh(--> Nil)
 {
     my Bool:D $disable-ipv6 = $.config.disable-ipv6;
@@ -1461,12 +1635,14 @@ method !unmount(--> Nil)
     # C<umount -R> fails initially on void, resume after error
     CATCH { default { .resume } };
     run(qw<umount --recursive --verbose /mnt>);
+    run(qw<vgchange --activate n>);
     run(qqw<cryptsetup luksClose $vault-name>);
     # print instructions for manual cleanup
     my Str:D $msg = qq:to/EOF/.trim;
     Manual cleanup after `voidvault new` is recommended [1]:
 
         # umount -R /mnt
+        # vgchange --activate n
         # cryptsetup luksClose $vault-name
 
     [1]: https://github.com/atweiden/voidvault/blob/master/doc/TODO.md
@@ -2036,10 +2212,10 @@ multi sub replace(
     # drivers are C<*.ko*> files in C</lib/modules>
     my Str:D @driver = qw<
         ahci
-        btrfs
         libcrc32c
         lz4
         lz4_compress
+        nilfs2
     >;
     push(@driver, 'crc32c-intel') if $processor eq 'INTEL';
     push(@driver, 'i915') if $graphics eq 'INTEL';
@@ -2058,9 +2234,9 @@ multi sub replace(
     my Str:D $file = sprintf(Q{/mnt/etc/dracut.conf.d/%s.conf}, $subject);
     # modules are found in C</usr/lib/dracut/modules.d>
     my Str:D @module = qw<
-        btrfs
         crypt
         kernel-modules
+        lvm
     >;
     my Str:D $replace = sprintf(Q{%s=" %s "}, $subject, @module.join(' '));
     spurt($file, $replace ~ "\n");
@@ -2112,6 +2288,7 @@ multi sub replace(
         Bool:D $disable-ipv6,
         Graphics:D $graphics,
         Str:D $partition-vault,
+        PoolName:D $pool-name,
         VaultName:D $vault-name
     )
     --> Nil
@@ -2125,7 +2302,8 @@ multi sub replace(
         ==> replace('grub', 'GRUB_DISABLE_RECOVERY')
         ==> replace('grub', 'GRUB_ENABLE_CRYPTODISK')
         ==> replace('grub', 'GRUB_TERMINAL_INPUT')
-        ==> replace('grub', 'GRUB_TERMINAL_OUTPUT');
+        ==> replace('grub', 'GRUB_TERMINAL_OUTPUT')
+        ==> replace('grub', 'GRUB_PRELOAD_MODULES');
     my Str:D $replace = @replace.join("\n");
     spurt($file, $replace ~ "\n");
 }
@@ -2136,6 +2314,7 @@ multi sub replace(
     Bool:D $disable-ipv6,
     Graphics:D $graphics,
     Str:D $partition-vault,
+    PoolName:D $pool-name,
     VaultName:D $vault-name,
     Str:D @line
     --> Array[Str:D]
@@ -2145,11 +2324,12 @@ multi sub replace(
     my Str:D $vault-uuid =
         qqx<blkid --match-tag UUID --output value $partition-vault>.trim;
     my Str:D @grub-cmdline-linux = qqw<
-        rootflags=subvol=@
         rd.auto=1
         rd.luks=1
         rd.luks.name=$vault-uuid=$vault-name
         rd.luks.uuid=$vault-uuid
+        dolvm
+        root=/dev/$pool-name/root
         loglevel=6
     >;
     # enable slub/slab allocator free poisoning (needs CONFIG_SLUB_DEBUG=y)
@@ -2241,6 +2421,21 @@ multi sub replace(
     @line;
 }
 
+multi sub replace(
+    'grub',
+    Str:D $subject where 'GRUB_PRELOAD_MODULES',
+    Str:D @line
+    --> Array[Str:D]
+)
+{
+    # if C<GRUB_PRELOAD_MODULES> not found, append to bottom of file
+    my UInt:D $index = @line.first(/^'#'?$subject/, :k) // @line.elems;
+    # preload lvm module
+    my Str:D $replace = sprintf(Q{%s="lvm"}, $subject);
+    @line[$index] = $replace;
+    @line;
+}
+
 # --- end grub }}}
 # --- 10_linux {{{
 
@@ -2389,6 +2584,98 @@ multi sub replace(
 }
 
 # --- end 99-sysctl.conf }}}
+# --- nilfs_cleanerd.conf {{{
+
+multi sub replace(
+    'nilfs_cleanerd.conf'
+    --> Nil
+)
+{
+    my Str:D $file = '/mnt/etc/nilfs_cleanerd.conf';
+    my Str:D @replace =
+        $file.IO.lines
+        # do continuous cleaning
+        ==> replace('nilfs_cleanerd.conf', 'min_clean_segments')
+        # increase maximum number of clean segments
+        ==> replace('nilfs_cleanerd.conf', 'max_clean_segments')
+        # decrease clean segment check interval
+        ==> replace('nilfs_cleanerd.conf', 'clean_check_interval')
+        # decrease cleaning interval
+        ==> replace('nilfs_cleanerd.conf', 'cleaning_interval')
+        # increase minimum number of reclaimable blocks in a segment
+        # before it can be cleaned
+        ==> replace('nilfs_cleanerd.conf', 'min_reclaimable_blocks');
+    my Str:D $replace = @replace.join("\n");
+    spurt($file, $replace ~ "\n");
+}
+
+multi sub replace(
+    'nilfs_cleanerd.conf',
+    Str:D $subject where 'min_clean_segments',
+    Str:D @line
+    --> Array[Str:D]
+)
+{
+    my UInt:D $index = @line.first(/^$subject/, :k);
+    my Str:D $replace = sprintf(Q{%s 0}, $subject);
+    @line[$index] = $replace;
+    @line;
+}
+
+multi sub replace(
+    'nilfs_cleanerd.conf',
+    Str:D $subject where 'max_clean_segments',
+    Str:D @line
+    --> Array[Str:D]
+)
+{
+    my UInt:D $index = @line.first(/^$subject/, :k);
+    # double C<%> symbol is quirk of sprintf syntax for C<90%>
+    my Str:D $replace = sprintf(Q{%s 90%%}, $subject);
+    @line[$index] = $replace;
+    @line;
+}
+
+multi sub replace(
+    'nilfs_cleanerd.conf',
+    Str:D $subject where 'clean_check_interval',
+    Str:D @line
+    --> Array[Str:D]
+)
+{
+    my UInt:D $index = @line.first(/^$subject/, :k);
+    my Str:D $replace = sprintf(Q{%s 2}, $subject);
+    @line[$index] = $replace;
+    @line;
+}
+
+multi sub replace(
+    'nilfs_cleanerd.conf',
+    Str:D $subject where 'cleaning_interval',
+    Str:D @line
+    --> Array[Str:D]
+)
+{
+    my UInt:D $index = @line.first(/^$subject/, :k);
+    my Str:D $replace = sprintf(Q{%s 2}, $subject);
+    @line[$index] = $replace;
+    @line;
+}
+
+multi sub replace(
+    'nilfs_cleanerd.conf',
+    Str:D $subject where 'min_reclaimable_blocks',
+    Str:D @line
+    --> Array[Str:D]
+)
+{
+    my UInt:D $index = @line.first(/^$subject/, :k);
+    my Str:D $replace = sprintf(Q{%s 60%%}, $subject);
+    @line[$index] = $replace;
+    @line;
+}
+
+# --- end nilfs_cleanerd.conf }}}
 # --- sshd_config {{{
 
 multi sub replace(
diff --git a/lib/Voidvault/Config.pm6 b/lib/Voidvault/Config.pm6
index 1d230e03..36e33002 100644
--- a/lib/Voidvault/Config.pm6
+++ b/lib/Voidvault/Config.pm6
@@ -103,6 +103,12 @@ has VaultPass $.vault-pass =
         ?? Voidvault::Config.gen-vault-pass(%*ENV<VOIDVAULT_VAULT_PASS>)
         !! Nil;
 
+# name for LVM volume group (default: vg0)
+has PoolName:D $.pool-name =
+    %*ENV<VOIDVAULT_POOL_NAME>
+        ?? Voidvault::Config.gen-pool-name(%*ENV<VOIDVAULT_POOL_NAME>)
+        !! prompt-name(:pool);
+
 # name for host (default: vault)
 has HostName:D $.host-name =
     %*ENV<VOIDVAULT_HOSTNAME>
@@ -182,6 +188,7 @@ submethod BUILD(
     Str :$keymap,
     Str :$locale,
     Str :$partition,
+    Str :$pool-name,
     Str :$processor,
     Str :$repository,
     Str :$root-pass,
@@ -213,6 +220,8 @@ submethod BUILD(
         if $locale;
     $!partition = $partition
         if $partition;
+    $!pool-name = Voidvault::Config.gen-pool-name($pool-name)
+        if $pool-name;
     $!processor = Voidvault::Config.gen-processor($processor)
         if $processor;
     $!repository = $repository
@@ -273,6 +282,7 @@ method new(
         Str :keymap($),
         Str :locale($),
         Str :partition($),
+        Str :pool-name($),
         Str :processor($),
         Str :repository($),
         Str :root-pass($),
@@ -325,6 +335,12 @@ method gen-locale(Str:D $l --> Locale:D)
     my Locale:D $locale = $l or die("Sorry, invalid locale 「$l」");
 }
 
+# confirm pool name $p is valid PoolName and return PoolName
+method gen-pool-name(Str:D $p --> PoolName:D)
+{
+    my PoolName:D $pool-name = $p or die("Sorry, invalid pool name 「$p」");
+}
+
 # confirm processor $p is valid Processor and return Processor
 method gen-processor(Str:D $p --> Processor:D)
 {
@@ -629,6 +645,30 @@ multi sub prompt-name(
     }
 }
 
+multi sub prompt-name(
+    Bool:D :pool($)! where .so
+    --> PoolName:D
+)
+{
+    my PoolName:D $pool-name = do {
+        my PoolName:D $response-default = 'vg0';
+        my Str:D $prompt-text = "Enter pool name [$response-default]: ";
+        my Str:D $help-text = q:to/EOF/.trim;
+        Determining name of LVM volume group...
+
+        Cannot be named the same as vault. Name should be unique in /dev/.
+
+        Leave blank if you don't know what this is
+        EOF
+        tprompt(
+            PoolName,
+            $response-default,
+            :$prompt-text,
+            :$help-text
+        );
+    }
+}
+
 multi sub prompt-name(
     Bool:D :user($)! where .so,
     Bool:D :admin($)! where .so
diff --git a/lib/Voidvault/Grammar.pm6 b/lib/Voidvault/Grammar.pm6
index 9879cbe8..67120443 100644
--- a/lib/Voidvault/Grammar.pm6
+++ b/lib/Voidvault/Grammar.pm6
@@ -38,6 +38,21 @@ regex host-name
     $
 }
 
+# LVM volume group name validation
+token pool-name
+{
+    # from `man 8 lvm` line 136:
+    # - VG name can only contain valid chars: A-Z a-z 0-9 + _ . -
+    # - VG name cannot begin with a hyphen
+    # - VG name cannot be anything that exists in /dev/ at the time of creation
+    # - VG name cannot be `.` or `..`
+    (
+        <+alnum +[+] +[_] +[\.]>
+        <+alnum +[+] +[_] +[\.] +[-]>*
+    )
+    { $0 !~~ /^^ '.' ** 1..2 $$/ or fail }
+}
+
 # linux username validation
 regex user-name
 {
diff --git a/lib/Voidvault/Types.pm6 b/lib/Voidvault/Types.pm6
index 01e6fdc2..ebc117af 100644
--- a/lib/Voidvault/Types.pm6
+++ b/lib/Voidvault/Types.pm6
@@ -1095,6 +1095,12 @@ subset LibcFlavor of Str is export where { @libc.grep($_) };
 # locale
 subset Locale of Str is export where { %locales.keys.grep($_) };
 
+# LVM volume group name
+subset PoolName of Str is export where
+{
+    Voidvault::Grammar.parse($_, :rule<pool-name>);
+}
+
 # processor
 subset Processor of Str is export where { %processors.keys.grep($_) };
 
diff --git a/lib/Voidvault/Utils.pm6 b/lib/Voidvault/Utils.pm6
index 16bdc45e..e59e794f 100644
--- a/lib/Voidvault/Utils.pm6
+++ b/lib/Voidvault/Utils.pm6
@@ -25,91 +25,6 @@ constant $PBKDF2-LENGTH-HASH = 100;
 constant $PBKDF2-LENGTH-SALT = 100;
 
 
-# -----------------------------------------------------------------------------
-# copy-on-write
-# -----------------------------------------------------------------------------
-
-method disable-cow(
-    *%opt (
-        Bool :clean($),
-        Bool :recursive($),
-        Str :permissions($),
-        Str :user($),
-        Str :group($)
-    ),
-    *@directory
-    --> Nil
-)
-{
-    # https://wiki.archlinux.org/index.php/Btrfs#Disabling_CoW
-    @directory.map(-> Str:D $directory { disable-cow($directory, |%opt) });
-}
-
-multi sub disable-cow(
-    Str:D $directory,
-    Bool:D :clean($)! where .so,
-    # ignored, recursive is implied with :clean
-    Bool :recursive($),
-    Str:D :$permissions = '755',
-    Str:D :$user = $*USER,
-    Str:D :$group = $*GROUP
-    --> Nil
-)
-{
-    my Str:D $orig-dir = ~$directory.IO.resolve;
-    $orig-dir.IO.e && $orig-dir.IO.r && $orig-dir.IO.d
-        or die('directory failed exists readable directory test');
-    my Str:D $backup-dir = sprintf(Q{%s-old}, $orig-dir);
-    rename($orig-dir, $backup-dir);
-    mkdir($orig-dir);
-    run(qqw<chmod $permissions $orig-dir>);
-    run(qqw<chown $user:$group $orig-dir>);
-    run(qqw<chattr -R +C $orig-dir>);
-    dir($backup-dir).map(-> IO::Path:D $file {
-        run(qqw<
-            cp
-            --no-dereference
-            --preserve=links,mode,ownership,timestamps
-            $file
-            $orig-dir
-        >);
-    });
-    run(qqw<rm --recursive --force $backup-dir>);
-}
-
-multi sub disable-cow(
-    Str:D $directory,
-    Bool :clean($),
-    Bool:D :recursive($)! where .so,
-    Str :permissions($),
-    Str :user($),
-    Str :group($)
-    --> Nil
-)
-{
-    my Str:D $orig-dir = ~$directory.IO.resolve;
-    $orig-dir.IO.e && $orig-dir.IO.r && $orig-dir.IO.d
-        or die('directory failed exists readable directory test');
-    run(qqw<chattr -R +C $orig-dir>);
-}
-
-multi sub disable-cow(
-    Str:D $directory,
-    Bool :clean($),
-    Bool :recursive($),
-    Str :permissions($),
-    Str :user($),
-    Str :group($)
-    --> Nil
-)
-{
-    my Str:D $orig-dir = ~$directory.IO.resolve;
-    $orig-dir.IO.e && $orig-dir.IO.r && $orig-dir.IO.d
-        or die('directory failed exists readable directory test');
-    run(qqw<chattr +C $orig-dir>);
-}
-
-
 # -----------------------------------------------------------------------------
 # password hashes
 # -----------------------------------------------------------------------------
diff --git a/scripts/mount-system.sh b/scripts/mount-system.sh
index 90853ccc..b600199c 100755
--- a/scripts/mount-system.sh
+++ b/scripts/mount-system.sh
@@ -1,39 +1,49 @@
 #!/bin/bash
 
 # ----------------------------------------------------------------------------
-# mount-system: mount voidvault btrfs subvolumes and efi partition
+# mount-system: mount voidvault nilfs+lvm on luks and efi partition
 # ----------------------------------------------------------------------------
 # instructions
 # - modify target partition (`_partition=/dev/sda`) as needed
 # - run `cryptsetup luksOpen /dev/sda3 vault` before running this script
 
 # setup
-_btrfs_subvolumes=(''
-                   'boot'
-                   'home'
-                   'opt'
-                   'srv'
-                   'var'
-                   'var-cache-xbps'
-                   'var-log'
-                   'var-opt'
-                   'var-spool'
-                   'var-tmp')
-# use lzo compression because grub does not yet support zstd
-_compression='lzo'
-_mount_options="rw,lazytime,compress=$_compression,space_cache"
+_lvs=('boot'
+      'opt'
+      'srv'
+      'var'
+      'var-cache-xbps'
+      'var-log'
+      'var-opt'
+      'var-spool'
+      'var-tmp'
+      'home')
+_mount_options='rw,lazytime'
 _partition='/dev/sda'
+_pool_name='vg0'
 _vault_name='vault'
 
-# mount btrfs subvolumes starting with root ('')
-for _btrfs_subvolume in "${_btrfs_subvolumes[@]}"; do
-  _btrfs_dir="${_btrfs_subvolume//-//}"
-  mkdir --parents "/mnt/$_btrfs_dir"
+# activate lvm lvs
+vgchange --activate y
+
+# mount root lv
+mkdir --parents /mnt
+mount \
+  --types nilfs2 \
+  --options "$_mount_options" \
+  "/dev/$_pool_name/root" \
+  /mnt
+
+# mount remaining lvs
+for _lv in "${_lvs[@]}"; do
+  # replace hyphen in volume name with forward slash
+  _dir="${_lv//-//}"
+  mkdir --parents "/mnt/$_dir"
   mount \
-    --types btrfs \
-    --options "$_mount_options,subvol=@$_btrfs_subvolume" \
-    "/dev/mapper/$_vault_name" \
-    "/mnt/$_btrfs_dir"
+    --types nilfs2 \
+    --options "$_mount_options" \
+    "/dev/$_pool_name/$_lv" \
+    "/mnt/$_dir"
 done
 
 # mount uefi boot partition
diff --git a/scripts/umount-system.sh b/scripts/umount-system.sh
index 2b0b6a82..018e9fa9 100755
--- a/scripts/umount-system.sh
+++ b/scripts/umount-system.sh
@@ -1,9 +1,19 @@
 #!/bin/bash
 
 # ----------------------------------------------------------------------------
-# umount-system: unmount voidvault btrfs subvolumes and efi partition
+# umount-system: unmount voidvault nilfs+lvm on luks and efi partition
 # ----------------------------------------------------------------------------
 # instructions
-# - run `cryptsetup luksClose vault` after running this script
+# - modify vault name (`_vault_name='vault'`) as needed
 
+# setup
+_vault_name='vault'
+
+# unmount filesystems
 umount --recursive /mnt
+
+# deactivate lvm lvs
+vgchange --activate n
+
+# close vault
+cryptsetup luksClose "$_vault_name"