19ce5874b7
Ubuntu 20.04's GRUB supports multiple EFI disks. There is a small caveat in that it doesn't prompt in the chroot, but it works fine after the reboot. Using the stock support means that the ESPs will be kept in sync automatically. Signed-off-by: Richard Laager <rlaager@wiktel.com> Refs issue #55
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.. highlight:: sh
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|
||
Ubuntu 20.04 Root on ZFS
|
||
========================
|
||
|
||
.. contents:: Table of Contents
|
||
:local:
|
||
|
||
Errata
|
||
------
|
||
|
||
If you previously installed using this guide, please apply these fixes if
|
||
applicable:
|
||
|
||
/boot/grub Not Mounted
|
||
~~~~~~~~~~~~~~~~~~~~~~
|
||
|
||
| **Severity:** Grave
|
||
| **Fixed:** 2020-05-30
|
||
|
||
For a mirror or raidz topology, ``/boot/grub`` is on a separate dataset. This
|
||
is now ``bpool/BOOT/ubuntu_UUID/grub``, but was previously ``bpool/grub``.
|
||
Unfortunately, zsys sets ``canmount=off`` on ``bpool/grub``, so it is not
|
||
mounted. As a result, updates the GRUB configuration will be written to the
|
||
``/boot`` filesystem and not used by GRUB (because it is still looking in
|
||
``bpool/grub``). Check for ``bpool/grub``::
|
||
|
||
zfs list bpool/grub
|
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|
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If this says “dataset does not exist”, you are good. If it exists, fix it.
|
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|
||
Once you start this process, the system will be unbootable until you have
|
||
completed it. Do not reboot until you have completed all of the steps.
|
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|
||
#. Rename the dataset::
|
||
|
||
umount /boot/grub
|
||
# Ignore any error about it not being mounted.
|
||
|
||
rm -rf /boot/grub
|
||
|
||
zfs list -r bpool
|
||
# Replace UUID below:
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||
zfs rename bpool/grub bpool/BOOT/ubuntu_UUID/grub
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||
zfs inherit com.ubuntu.zsys:bootfs bpool/BOOT/ubuntu_UUID/grub
|
||
zfs set canmount=on bpool/BOOT/ubuntu_UUID/grub
|
||
zfs mount bpool/BOOT/ubuntu_UUID/grub
|
||
|
||
#. Ensure that zed updated the cache to use ``bpool/BOOT/ubuntu_UUID/grub``::
|
||
|
||
grep grub /etc/zfs/zfs-list.cache/bpool
|
||
|
||
#. Rebuild the initrd and reinstall GRUB::
|
||
|
||
update-initramfs -c -k all
|
||
update-grub
|
||
grub-install --target=x86_64-efi --efi-directory=/boot/efi \
|
||
--bootloader-id=ubuntu --recheck --no-floppy
|
||
|
||
Run this for the additional disk(s), incrementing the “2” to “3” and so on
|
||
for both ``/boot/efi2`` and ``ubuntu-2``::
|
||
|
||
cp -a /boot/efi/EFI /boot/efi2
|
||
grub-install --target=x86_64-efi --efi-directory=/boot/efi2 \
|
||
--bootloader-id=ubuntu-2 --recheck --no-floppy
|
||
|
||
Check that these have ``set prefix=($root)'/BOOT/ubuntu_UUID/grub@'``::
|
||
|
||
grep prefix= \
|
||
/boot/efi/EFI/ubuntu/grub.cfg \
|
||
/boot/efi2/EFI/ubuntu-2/grub.cfg
|
||
|
||
#. If using encryption, patch a dependency loop::
|
||
|
||
sudo apt install --yes curl patch
|
||
curl https://launchpadlibrarian.net/478315221/2150-fix-systemd-dependency-loops.patch | \
|
||
sed "s|/etc|/lib|;s|\.in$||" | (cd / ; patch -p1)
|
||
|
||
#. Disable grub-initrd-fallback.service::
|
||
|
||
systemctl mask grub-initrd-fallback.service
|
||
|
||
AccountsService Not Mounted
|
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~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
||
| **Severity:** Normal
|
||
| **Fixed:** 2020-05-28
|
||
|
||
The HOWTO previously had a typo in AccountsService (where Accounts is plural)
|
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as AccountServices (where Services is plural). This means that AccountsService
|
||
data will be written to the root filesystem. This is only harmful in the event
|
||
of a rollback of the root filesystem that does not include a rollback of the
|
||
user data. Check it::
|
||
|
||
zfs list | grep Account
|
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|
||
If the “s” is on “Accounts”, you are good. If it is on “Services”, fix it::
|
||
|
||
mv /var/lib/AccountsService /var/lib/AccountsService-old
|
||
zfs list -r rpool
|
||
# Replace the UUID twice below:
|
||
zfs rename rpool/ROOT/ubuntu_UUID/var/lib/AccountServices \
|
||
rpool/ROOT/ubuntu_UUID/var/lib/AccountsService
|
||
mv /var/lib/AccountsService-old/* /var/lib/AccountsService
|
||
rmdir /var/lib/AccountsService-old
|
||
|
||
Overview
|
||
--------
|
||
|
||
Ubuntu Installer
|
||
~~~~~~~~~~~~~~~~
|
||
|
||
The Ubuntu installer has `support for root-on-ZFS
|
||
<https://arstechnica.com/gadgets/2020/03/ubuntu-20-04s-zsys-adds-zfs-snapshots-to-package-management/>`__.
|
||
This HOWTO produces nearly identical results as the Ubuntu installer because of
|
||
`bidirectional collaboration
|
||
<https://ubuntu.com/blog/enhancing-our-zfs-support-on-ubuntu-19-10-an-introduction>`__.
|
||
|
||
If you want a single-disk, unencrypted, desktop install, use the installer. It
|
||
is far easier and faster than doing everything by hand.
|
||
|
||
If you want a ZFS native encrypted, desktop install, you can `trivially edit
|
||
the installer
|
||
<https://linsomniac.gitlab.io/post/2020-04-09-ubuntu-2004-encrypted-zfs/>`__.
|
||
The ``-o recordsize=1M`` there is unrelated to encryption; omit that unless
|
||
you understand it. Make sure to use a password that is at least 8 characters
|
||
or this hack will crash the installer. Additionally, once the system is
|
||
installed, you should switch to encrypted swap::
|
||
|
||
swapon -v
|
||
# Note the device, including the partition.
|
||
|
||
ls -l /dev/disk/by-id/
|
||
# Find the by-id name of the disk.
|
||
|
||
sudo swapoff -a
|
||
sudo vi /etc/fstab
|
||
# Remove the swap entry.
|
||
|
||
sudo apt install --yes cryptsetup curl patch
|
||
|
||
curl https://launchpadlibrarian.net/478315221/2150-fix-systemd-dependency-loops.patch | \
|
||
sed "s|/etc|/lib|;s|\.in$||" | (cd / ; sudo patch -p1)
|
||
|
||
# Replace DISK-partN as appropriate from above:
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||
echo swap /dev/disk/by-id/DISK-partN /dev/urandom \
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||
swap,cipher=aes-xts-plain64:sha256,size=512 | sudo tee -a /etc/crypttab
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||
echo /dev/mapper/swap none swap defaults 0 0 | sudo tee -a /etc/fstab
|
||
|
||
`Hopefully the installer will gain encryption support in
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the future
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||
<https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1857398>`__.
|
||
|
||
If you want to setup a mirror or raidz topology, use LUKS encryption, and/or
|
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install a server (no desktop GUI), use this HOWTO.
|
||
|
||
Raspberry Pi
|
||
~~~~~~~~~~~~
|
||
|
||
If you are looking to install on a Raspberry Pi, see
|
||
:doc:`Ubuntu 20.04 Root on ZFS for Raspberry Pi`.
|
||
|
||
Caution
|
||
~~~~~~~
|
||
|
||
- This HOWTO uses a whole physical disk.
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||
- Do not use these instructions for dual-booting.
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||
- Backup your data. Any existing data will be lost.
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||
|
||
System Requirements
|
||
~~~~~~~~~~~~~~~~~~~
|
||
|
||
- `Ubuntu 20.04.1 (“Focal”) Desktop CD
|
||
<https://releases.ubuntu.com/20.04/ubuntu-20.04.1-desktop-amd64.iso>`__
|
||
(*not* any server images)
|
||
- Installing on a drive which presents 4 KiB logical sectors (a “4Kn” drive)
|
||
only works with UEFI booting. This not unique to ZFS. `GRUB does not and
|
||
will not work on 4Kn with legacy (BIOS) booting.
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||
<http://savannah.gnu.org/bugs/?46700>`__
|
||
|
||
Computers that have less than 2 GiB of memory run ZFS slowly. 4 GiB of memory
|
||
is recommended for normal performance in basic workloads. If you wish to use
|
||
deduplication, you will need `massive amounts of RAM
|
||
<http://wiki.freebsd.org/ZFSTuningGuide#Deduplication>`__. Enabling
|
||
deduplication is a permanent change that cannot be easily reverted.
|
||
|
||
Support
|
||
~~~~~~~
|
||
|
||
If you need help, reach out to the community using the :ref:`mailing_lists` or IRC at
|
||
`#zfsonlinux <irc://irc.freenode.net/#zfsonlinux>`__ on `freenode
|
||
<https://freenode.net/>`__. If you have a bug report or feature request
|
||
related to this HOWTO, please `file a new issue and mention @rlaager
|
||
<https://github.com/openzfs/openzfs-docs/issues/new?body=@rlaager,%20I%20have%20the%20following%20issue%20with%20the%20Ubuntu%2020.04%20Root%20on%20ZFS%20HOWTO:>`__.
|
||
|
||
Contributing
|
||
~~~~~~~~~~~~
|
||
|
||
#. Fork and clone: https://github.com/openzfs/openzfs-docs
|
||
|
||
#. Install the tools::
|
||
|
||
sudo apt install python3-pip
|
||
pip3 install -r docs/requirements.txt
|
||
# Add ~/.local/bin to your $PATH, e.g. by adding this to ~/.bashrc:
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||
PATH=$HOME/.local/bin:$PATH
|
||
|
||
#. Make your changes.
|
||
|
||
#. Test::
|
||
|
||
cd docs
|
||
make html
|
||
sensible-browser _build/html/index.html
|
||
|
||
#. ``git commit --signoff`` to a branch, ``git push``, and create a pull
|
||
request. Mention @rlaager.
|
||
|
||
Encryption
|
||
~~~~~~~~~~
|
||
|
||
This guide supports three different encryption options: unencrypted, ZFS
|
||
native encryption, and LUKS. With any option, all ZFS features are fully
|
||
available.
|
||
|
||
Unencrypted does not encrypt anything, of course. With no encryption
|
||
happening, this option naturally has the best performance.
|
||
|
||
ZFS native encryption encrypts the data and most metadata in the root
|
||
pool. It does not encrypt dataset or snapshot names or properties. The
|
||
boot pool is not encrypted at all, but it only contains the bootloader,
|
||
kernel, and initrd. (Unless you put a password in ``/etc/fstab``, the
|
||
initrd is unlikely to contain sensitive data.) The system cannot boot
|
||
without the passphrase being entered at the console. Performance is
|
||
good. As the encryption happens in ZFS, even if multiple disks (mirror
|
||
or raidz topologies) are used, the data only has to be encrypted once.
|
||
|
||
LUKS encrypts almost everything. The only unencrypted data is the bootloader,
|
||
kernel, and initrd. The system cannot boot without the passphrase being
|
||
entered at the console. Performance is good, but LUKS sits underneath ZFS, so
|
||
if multiple disks (mirror or raidz topologies) are used, the data has to be
|
||
encrypted once per disk.
|
||
|
||
Step 1: Prepare The Install Environment
|
||
---------------------------------------
|
||
|
||
#. Boot the Ubuntu Live CD. Select Try Ubuntu. Connect your system to the
|
||
Internet as appropriate (e.g. join your WiFi network). Open a terminal
|
||
(press Ctrl-Alt-T).
|
||
|
||
#. Setup and update the repositories::
|
||
|
||
sudo apt-add-repository universe
|
||
sudo apt update
|
||
|
||
#. Optional: Install and start the OpenSSH server in the Live CD environment:
|
||
|
||
If you have a second system, using SSH to access the target system can be
|
||
convenient::
|
||
|
||
passwd
|
||
# There is no current password.
|
||
sudo apt install --yes openssh-server vim
|
||
|
||
Installing the full ``vim`` package fixes terminal problems that occur when
|
||
using the ``vim-tiny`` package (that ships in the Live CD environment) over
|
||
SSH.
|
||
|
||
**Hint:** You can find your IP address with
|
||
``ip addr show scope global | grep inet``. Then, from your main machine,
|
||
connect with ``ssh ubuntu@IP``.
|
||
|
||
#. Become root::
|
||
|
||
sudo -i
|
||
|
||
#. Install ZFS in the Live CD environment::
|
||
|
||
apt install --yes debootstrap gdisk zfs-initramfs
|
||
systemctl stop zed
|
||
|
||
Step 2: Disk Formatting
|
||
-----------------------
|
||
|
||
#. Set a variable with the disk name::
|
||
|
||
DISK=/dev/disk/by-id/scsi-SATA_disk1
|
||
|
||
Always use the long ``/dev/disk/by-id/*`` aliases with ZFS. Using the
|
||
``/dev/sd*`` device nodes directly can cause sporadic import failures,
|
||
especially on systems that have more than one storage pool.
|
||
|
||
**Hints:**
|
||
|
||
- ``ls -la /dev/disk/by-id`` will list the aliases.
|
||
- Are you doing this in a virtual machine? If your virtual disk is missing
|
||
from ``/dev/disk/by-id``, use ``/dev/vda`` if you are using KVM with
|
||
virtio; otherwise, read the `troubleshooting <#troubleshooting>`__
|
||
section.
|
||
|
||
#. If you are re-using a disk, clear it as necessary:
|
||
|
||
If the disk was previously used in an MD array::
|
||
|
||
apt install --yes mdadm
|
||
|
||
# See if one or more MD arrays are active:
|
||
cat /proc/mdstat
|
||
# If so, stop them (replace ``md0`` as required):
|
||
mdadm --stop /dev/md0
|
||
|
||
# For an array using the whole disk:
|
||
mdadm --zero-superblock --force $DISK
|
||
# For an array using a partition (e.g. a swap partition per this HOWTO):
|
||
mdadm --zero-superblock --force ${DISK}-part2
|
||
|
||
Clear the partition table::
|
||
|
||
sgdisk --zap-all $DISK
|
||
|
||
If you get a message about the kernel still using the old partition table,
|
||
reboot and start over (except that you can skip this step).
|
||
|
||
#. Create bootloader partition(s)::
|
||
|
||
sgdisk -n1:1M:+512M -t1:EF00 $DISK
|
||
|
||
# For legacy (BIOS) booting:
|
||
sgdisk -a1 -n5:24K:+1000K -t5:EF02 $DISK
|
||
|
||
**Note:** While the Ubuntu installer uses an MBR label for legacy (BIOS)
|
||
booting, this HOWTO uses GPT partition labels for both UEFI and legacy
|
||
(BIOS) booting. This is simpler than having two options. It is also
|
||
provides forward compatibility (future proofing). In other words, for
|
||
legacy (BIOS) booting, this will allow you to move the disk(s) to a new
|
||
system/motherboard in the future without having to rebuild the pool (and
|
||
restore your data from a backup). The ESP is created in both cases for
|
||
similar reasons. Additionally, the ESP is used for ``/boot/grub`` in
|
||
single-disk installs, as :ref:`discussed below <boot-grub-esp>`.
|
||
|
||
#. Create a partition for swap:
|
||
|
||
Previous versions of this HOWTO put swap on a zvol. `Ubuntu recommends
|
||
against this configuration due to deadlocks.
|
||
<https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1847628>`__ There
|
||
is `a bug report upstream
|
||
<https://github.com/zfsonlinux/zfs/issues/7734>`__.
|
||
|
||
Putting swap on a partition gives up the benefit of ZFS checksums (for your
|
||
swap). That is probably the right trade-off given the reports of ZFS
|
||
deadlocks with swap. If you are bothered by this, simply do not enable
|
||
swap.
|
||
|
||
Choose one of the following options if you want swap:
|
||
|
||
- For a single-disk install::
|
||
|
||
sgdisk -n2:0:+500M -t2:8200 $DISK
|
||
|
||
- For a mirror or raidz topology::
|
||
|
||
sgdisk -n2:0:+500M -t2:FD00 $DISK
|
||
|
||
Adjust the swap swize to your needs. If you wish to enable hiberation
|
||
(which only works for unencrypted installs), the swap partition must be
|
||
at least as large as the system's RAM.
|
||
|
||
#. Create a boot pool partition::
|
||
|
||
sgdisk -n3:0:+2G -t3:BE00 $DISK
|
||
|
||
The Ubuntu installer uses 5% of the disk space constrained to a minimum of
|
||
500 MiB and a maximum of 2 GiB. `Making this too small (and 500 MiB might
|
||
be too small) can result in an inability to upgrade the kernel.
|
||
<https://medium.com/@andaag/how-i-moved-a-ext4-ubuntu-install-to-encrypted-zfs-62af1170d46c>`__
|
||
|
||
#. Create a root pool partition:
|
||
|
||
Choose one of the following options:
|
||
|
||
- Unencrypted or ZFS native encryption::
|
||
|
||
sgdisk -n4:0:0 -t4:BF00 $DISK
|
||
|
||
- LUKS::
|
||
|
||
sgdisk -n4:0:0 -t4:8309 $DISK
|
||
|
||
If you are creating a mirror or raidz topology, repeat the partitioning
|
||
commands for all the disks which will be part of the pool.
|
||
|
||
#. Create the boot pool::
|
||
|
||
zpool create \
|
||
-o ashift=12 -d \
|
||
-o feature@async_destroy=enabled \
|
||
-o feature@bookmarks=enabled \
|
||
-o feature@embedded_data=enabled \
|
||
-o feature@empty_bpobj=enabled \
|
||
-o feature@enabled_txg=enabled \
|
||
-o feature@extensible_dataset=enabled \
|
||
-o feature@filesystem_limits=enabled \
|
||
-o feature@hole_birth=enabled \
|
||
-o feature@large_blocks=enabled \
|
||
-o feature@lz4_compress=enabled \
|
||
-o feature@spacemap_histogram=enabled \
|
||
-O acltype=posixacl -O canmount=off -O compression=lz4 \
|
||
-O devices=off -O normalization=formD -O relatime=on -O xattr=sa \
|
||
-O mountpoint=/boot -R /mnt \
|
||
bpool ${DISK}-part3
|
||
|
||
You should not need to customize any of the options for the boot pool.
|
||
|
||
GRUB does not support all of the zpool features. See ``spa_feature_names``
|
||
in `grub-core/fs/zfs/zfs.c
|
||
<http://git.savannah.gnu.org/cgit/grub.git/tree/grub-core/fs/zfs/zfs.c#n276>`__.
|
||
This step creates a separate boot pool for ``/boot`` with the features
|
||
limited to only those that GRUB supports, allowing the root pool to use
|
||
any/all features. Note that GRUB opens the pool read-only, so all
|
||
read-only compatible features are “supported” by GRUB.
|
||
|
||
**Hints:**
|
||
|
||
- If you are creating a mirror topology, create the pool using::
|
||
|
||
zpool create \
|
||
... \
|
||
bpool mirror \
|
||
/dev/disk/by-id/scsi-SATA_disk1-part3 \
|
||
/dev/disk/by-id/scsi-SATA_disk2-part3
|
||
|
||
- For raidz topologies, replace ``mirror`` in the above command with
|
||
``raidz``, ``raidz2``, or ``raidz3`` and list the partitions from
|
||
additional disks.
|
||
- The boot pool name is no longer arbitrary. It _must_ be ``bpool``.
|
||
If you really want to rename it, edit ``/etc/grub.d/10_linux_zfs`` later,
|
||
after GRUB is installed (and run ``update-grub``).
|
||
|
||
**Feature Notes:**
|
||
|
||
- The ``allocation_classes`` feature should be safe to use. However, unless
|
||
one is using it (i.e. a ``special`` vdev), there is no point to enabling
|
||
it. It is extremely unlikely that someone would use this feature for a
|
||
boot pool. If one cares about speeding up the boot pool, it would make
|
||
more sense to put the whole pool on the faster disk rather than using it
|
||
as a ``special`` vdev.
|
||
- The ``project_quota`` feature has been tested and is safe to use. This
|
||
feature is extremely unlikely to matter for the boot pool.
|
||
- The ``resilver_defer`` should be safe but the boot pool is small enough
|
||
that it is unlikely to be necessary.
|
||
- The ``spacemap_v2`` feature has been tested and is safe to use. The boot
|
||
pool is small, so this does not matter in practice.
|
||
- As a read-only compatible feature, the ``userobj_accounting`` feature
|
||
should be compatible in theory, but in practice, GRUB can fail with an
|
||
“invalid dnode type” error. This feature does not matter for ``/boot``
|
||
anyway.
|
||
|
||
#. Create the root pool:
|
||
|
||
Choose one of the following options:
|
||
|
||
- Unencrypted::
|
||
|
||
zpool create \
|
||
-o ashift=12 \
|
||
-O acltype=posixacl -O canmount=off -O compression=lz4 \
|
||
-O dnodesize=auto -O normalization=formD -O relatime=on \
|
||
-O xattr=sa -O mountpoint=/ -R /mnt \
|
||
rpool ${DISK}-part4
|
||
|
||
- ZFS native encryption::
|
||
|
||
zpool create \
|
||
-o ashift=12 \
|
||
-O encryption=aes-256-gcm \
|
||
-O keylocation=prompt -O keyformat=passphrase \
|
||
-O acltype=posixacl -O canmount=off -O compression=lz4 \
|
||
-O dnodesize=auto -O normalization=formD -O relatime=on \
|
||
-O xattr=sa -O mountpoint=/ -R /mnt \
|
||
rpool ${DISK}-part4
|
||
|
||
- LUKS::
|
||
|
||
cryptsetup luksFormat -c aes-xts-plain64 -s 512 -h sha256 ${DISK}-part4
|
||
cryptsetup luksOpen ${DISK}-part4 luks1
|
||
zpool create \
|
||
-o ashift=12 \
|
||
-O acltype=posixacl -O canmount=off -O compression=lz4 \
|
||
-O dnodesize=auto -O normalization=formD -O relatime=on \
|
||
-O xattr=sa -O mountpoint=/ -R /mnt \
|
||
rpool /dev/mapper/luks1
|
||
|
||
**Notes:**
|
||
|
||
- The use of ``ashift=12`` is recommended here because many drives
|
||
today have 4 KiB (or larger) physical sectors, even though they
|
||
present 512 B logical sectors. Also, a future replacement drive may
|
||
have 4 KiB physical sectors (in which case ``ashift=12`` is desirable)
|
||
or 4 KiB logical sectors (in which case ``ashift=12`` is required).
|
||
- Setting ``-O acltype=posixacl`` enables POSIX ACLs globally. If you
|
||
do not want this, remove that option, but later add
|
||
``-o acltype=posixacl`` (note: lowercase “o”) to the ``zfs create``
|
||
for ``/var/log``, as `journald requires ACLs
|
||
<https://askubuntu.com/questions/970886/journalctl-says-failed-to-search-journal-acl-operation-not-supported>`__
|
||
Also, `disabling ACLs apparently breaks umask handling with NFSv4
|
||
<https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/1779736>`__.
|
||
- Setting ``normalization=formD`` eliminates some corner cases relating
|
||
to UTF-8 filename normalization. It also implies ``utf8only=on``,
|
||
which means that only UTF-8 filenames are allowed. If you care to
|
||
support non-UTF-8 filenames, do not use this option. For a discussion
|
||
of why requiring UTF-8 filenames may be a bad idea, see `The problems
|
||
with enforced UTF-8 only filenames
|
||
<http://utcc.utoronto.ca/~cks/space/blog/linux/ForcedUTF8Filenames>`__.
|
||
- ``recordsize`` is unset (leaving it at the default of 128 KiB). If you
|
||
want to tune it (e.g. ``-o recordsize=1M``), see `these
|
||
<https://jrs-s.net/2019/04/03/on-zfs-recordsize/>`__ `various
|
||
<http://blog.programster.org/zfs-record-size>`__ `blog
|
||
<https://utcc.utoronto.ca/~cks/space/blog/solaris/ZFSFileRecordsizeGrowth>`__
|
||
`posts
|
||
<https://utcc.utoronto.ca/~cks/space/blog/solaris/ZFSRecordsizeAndCompression>`__.
|
||
- Setting ``relatime=on`` is a middle ground between classic POSIX
|
||
``atime`` behavior (with its significant performance impact) and
|
||
``atime=off`` (which provides the best performance by completely
|
||
disabling atime updates). Since Linux 2.6.30, ``relatime`` has been
|
||
the default for other filesystems. See `RedHat’s documentation
|
||
<https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/power_management_guide/relatime>`__
|
||
for further information.
|
||
- Setting ``xattr=sa`` `vastly improves the performance of extended
|
||
attributes
|
||
<https://github.com/zfsonlinux/zfs/commit/82a37189aac955c81a59a5ecc3400475adb56355>`__.
|
||
Inside ZFS, extended attributes are used to implement POSIX ACLs.
|
||
Extended attributes can also be used by user-space applications.
|
||
`They are used by some desktop GUI applications.
|
||
<https://en.wikipedia.org/wiki/Extended_file_attributes#Linux>`__
|
||
`They can be used by Samba to store Windows ACLs and DOS attributes;
|
||
they are required for a Samba Active Directory domain controller.
|
||
<https://wiki.samba.org/index.php/Setting_up_a_Share_Using_Windows_ACLs>`__
|
||
Note that ``xattr=sa`` is `Linux-specific
|
||
<https://openzfs.org/wiki/Platform_code_differences>`__. If you move your
|
||
``xattr=sa`` pool to another OpenZFS implementation besides ZFS-on-Linux,
|
||
extended attributes will not be readable (though your data will be). If
|
||
portability of extended attributes is important to you, omit the
|
||
``-O xattr=sa`` above. Even if you do not want ``xattr=sa`` for the whole
|
||
pool, it is probably fine to use it for ``/var/log``.
|
||
- Make sure to include the ``-part4`` portion of the drive path. If you
|
||
forget that, you are specifying the whole disk, which ZFS will then
|
||
re-partition, and you will lose the bootloader partition(s).
|
||
- ZFS native encryption defaults to ``aes-256-ccm``, but `the default has
|
||
changed upstream
|
||
<https://github.com/openzfs/zfs/commit/31b160f0a6c673c8f926233af2ed6d5354808393>`__
|
||
to ``aes-256-gcm``. `AES-GCM seems to be generally preferred over AES-CCM
|
||
<https://crypto.stackexchange.com/questions/6842/how-to-choose-between-aes-ccm-and-aes-gcm-for-storage-volume-encryption>`__,
|
||
`is faster now
|
||
<https://github.com/zfsonlinux/zfs/pull/9749#issuecomment-569132997>`__,
|
||
and `will be even faster in the future
|
||
<https://github.com/zfsonlinux/zfs/pull/9749>`__.
|
||
- For LUKS, the key size chosen is 512 bits. However, XTS mode requires two
|
||
keys, so the LUKS key is split in half. Thus, ``-s 512`` means AES-256.
|
||
- Your passphrase will likely be the weakest link. Choose wisely. See
|
||
`section 5 of the cryptsetup FAQ
|
||
<https://gitlab.com/cryptsetup/cryptsetup/wikis/FrequentlyAskedQuestions#5-security-aspects>`__
|
||
for guidance.
|
||
|
||
**Hints:**
|
||
|
||
- If you are creating a mirror topology, create the pool using::
|
||
|
||
zpool create \
|
||
... \
|
||
rpool mirror \
|
||
/dev/disk/by-id/scsi-SATA_disk1-part4 \
|
||
/dev/disk/by-id/scsi-SATA_disk2-part4
|
||
|
||
- For raidz topologies, replace ``mirror`` in the above command with
|
||
``raidz``, ``raidz2``, or ``raidz3`` and list the partitions from
|
||
additional disks.
|
||
- When using LUKS with mirror or raidz topologies, use
|
||
``/dev/mapper/luks1``, ``/dev/mapper/luks2``, etc., which you will have
|
||
to create using ``cryptsetup``.
|
||
- The pool name is arbitrary. If changed, the new name must be used
|
||
consistently. On systems that can automatically install to ZFS, the root
|
||
pool is named ``rpool`` by default.
|
||
|
||
Step 3: System Installation
|
||
---------------------------
|
||
|
||
#. Create filesystem datasets to act as containers::
|
||
|
||
zfs create -o canmount=off -o mountpoint=none rpool/ROOT
|
||
zfs create -o canmount=off -o mountpoint=none bpool/BOOT
|
||
|
||
#. Create filesystem datasets for the root and boot filesystems::
|
||
|
||
UUID=$(dd if=/dev/urandom of=/dev/stdout bs=1 count=100 2>/dev/null |
|
||
tr -dc 'a-z0-9' | cut -c-6)
|
||
|
||
zfs create -o canmount=noauto -o mountpoint=/ \
|
||
-o com.ubuntu.zsys:bootfs=yes \
|
||
-o com.ubuntu.zsys:last-used=$(date +%s) rpool/ROOT/ubuntu_$UUID
|
||
zfs mount rpool/ROOT/ubuntu_$UUID
|
||
|
||
zfs create -o canmount=noauto -o mountpoint=/boot \
|
||
bpool/BOOT/ubuntu_$UUID
|
||
zfs mount bpool/BOOT/ubuntu_$UUID
|
||
|
||
With ZFS, it is not normally necessary to use a mount command (either
|
||
``mount`` or ``zfs mount``). This situation is an exception because of
|
||
``canmount=noauto``.
|
||
|
||
#. Create datasets::
|
||
|
||
zfs create -o com.ubuntu.zsys:bootfs=no \
|
||
rpool/ROOT/ubuntu_$UUID/srv
|
||
zfs create -o com.ubuntu.zsys:bootfs=no -o canmount=off \
|
||
rpool/ROOT/ubuntu_$UUID/usr
|
||
zfs create rpool/ROOT/ubuntu_$UUID/usr/local
|
||
zfs create -o com.ubuntu.zsys:bootfs=no -o canmount=off \
|
||
rpool/ROOT/ubuntu_$UUID/var
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/games
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/lib
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/lib/AccountsService
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/lib/apt
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/lib/dpkg
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/lib/NetworkManager
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/log
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/mail
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/snap
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/spool
|
||
zfs create rpool/ROOT/ubuntu_$UUID/var/www
|
||
|
||
zfs create -o canmount=off -o mountpoint=/ \
|
||
rpool/USERDATA
|
||
zfs create -o com.ubuntu.zsys:bootfs-datasets=rpool/ROOT/ubuntu_$UUID \
|
||
-o canmount=on -o mountpoint=/root \
|
||
rpool/USERDATA/root_$UUID
|
||
|
||
For a mirror or raidz topology, create a dataset for ``/boot/grub``::
|
||
|
||
zfs create bpool/BOOT/ubuntu_$UUID/grub
|
||
|
||
A tmpfs is recommended later, but if you want a separate dataset for
|
||
``/tmp``::
|
||
|
||
zfs create -o com.ubuntu.zsys:bootfs=no \
|
||
rpool/ROOT/ubuntu_$UUID/tmp
|
||
chmod 1777 /mnt/tmp
|
||
|
||
The primary goal of this dataset layout is to separate the OS from user
|
||
data. This allows the root filesystem to be rolled back without rolling
|
||
back user data.
|
||
|
||
If you do nothing extra, ``/tmp`` will be stored as part of the root
|
||
filesystem. Alternatively, you can create a separate dataset for ``/tmp``,
|
||
as shown above. This keeps the ``/tmp`` data out of snapshots of your root
|
||
filesystem. It also allows you to set a quota on ``rpool/tmp``, if you want
|
||
to limit the maximum space used. Otherwise, you can use a tmpfs (RAM
|
||
filesystem) later.
|
||
|
||
#. Install the minimal system::
|
||
|
||
debootstrap focal /mnt
|
||
|
||
The ``debootstrap`` command leaves the new system in an unconfigured state.
|
||
An alternative to using ``debootstrap`` is to copy the entirety of a
|
||
working system into the new ZFS root.
|
||
|
||
Step 4: System Configuration
|
||
----------------------------
|
||
|
||
#. Configure the hostname:
|
||
|
||
Replace ``HOSTNAME`` with the desired hostname::
|
||
|
||
echo HOSTNAME > /mnt/etc/hostname
|
||
vi /mnt/etc/hosts
|
||
|
||
.. code-block:: text
|
||
|
||
Add a line:
|
||
127.0.1.1 HOSTNAME
|
||
or if the system has a real name in DNS:
|
||
127.0.1.1 FQDN HOSTNAME
|
||
|
||
**Hint:** Use ``nano`` if you find ``vi`` confusing.
|
||
|
||
#. Configure the network interface:
|
||
|
||
Find the interface name::
|
||
|
||
ip addr show
|
||
|
||
Adjust ``NAME`` below to match your interface name::
|
||
|
||
vi /mnt/etc/netplan/01-netcfg.yaml
|
||
|
||
.. code-block:: yaml
|
||
|
||
network:
|
||
version: 2
|
||
ethernets:
|
||
NAME:
|
||
dhcp4: true
|
||
|
||
Customize this file if the system is not a DHCP client.
|
||
|
||
#. Configure the package sources::
|
||
|
||
vi /mnt/etc/apt/sources.list
|
||
|
||
.. code-block:: sourceslist
|
||
|
||
deb http://archive.ubuntu.com/ubuntu focal main restricted universe multiverse
|
||
deb http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiverse
|
||
deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
|
||
deb http://security.ubuntu.com/ubuntu focal-security main restricted universe multiverse
|
||
|
||
#. Bind the virtual filesystems from the LiveCD environment to the new
|
||
system and ``chroot`` into it::
|
||
|
||
mount --rbind /dev /mnt/dev
|
||
mount --rbind /proc /mnt/proc
|
||
mount --rbind /sys /mnt/sys
|
||
chroot /mnt /usr/bin/env DISK=$DISK UUID=$UUID bash --login
|
||
|
||
**Note:** This is using ``--rbind``, not ``--bind``.
|
||
|
||
#. Configure a basic system environment::
|
||
|
||
apt update
|
||
|
||
Even if you prefer a non-English system language, always ensure that
|
||
``en_US.UTF-8`` is available::
|
||
|
||
dpkg-reconfigure locales tzdata keyboard-configuration console-setup
|
||
|
||
Install your preferred text editor::
|
||
|
||
apt install --yes nano
|
||
apt install --yes vim
|
||
|
||
Installing the full ``vim`` package fixes terminal problems that occur when
|
||
using the ``vim-tiny`` package (that is installed by ``debootstrap``) over
|
||
SSH.
|
||
|
||
#. For LUKS installs only, setup ``/etc/crypttab``::
|
||
|
||
apt install --yes cryptsetup
|
||
|
||
echo luks1 /dev/disk/by-uuid/$(blkid -s UUID -o value ${DISK}-part4) \
|
||
none luks,discard,initramfs > /etc/crypttab
|
||
|
||
The use of ``initramfs`` is a work-around for `cryptsetup does not support
|
||
ZFS <https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1612906>`__.
|
||
|
||
**Hint:** If you are creating a mirror or raidz topology, repeat the
|
||
``/etc/crypttab`` entries for ``luks2``, etc. adjusting for each disk.
|
||
|
||
#. Create the EFI filesystem:
|
||
|
||
Perform these steps for both UEFI and legacy (BIOS) booting::
|
||
|
||
apt install --yes dosfstools
|
||
|
||
mkdosfs -F 32 -s 1 -n EFI ${DISK}-part1
|
||
mkdir /boot/efi
|
||
echo /dev/disk/by-uuid/$(blkid -s UUID -o value ${DISK}-part1) \
|
||
/boot/efi vfat defaults 0 0 >> /etc/fstab
|
||
mount /boot/efi
|
||
|
||
For a mirror or raidz topology, repeat the `mkdosfs` for the additional
|
||
disks, but do not repeat the other commands.
|
||
|
||
**Note:** The ``-s 1`` for ``mkdosfs`` is only necessary for drives which
|
||
present 4 KiB logical sectors (“4Kn” drives) to meet the minimum cluster
|
||
size (given the partition size of 512 MiB) for FAT32. It also works fine on
|
||
drives which present 512 B sectors.
|
||
|
||
#. Put ``/boot/grub`` on the EFI System Partition:
|
||
|
||
.. _boot-grub-esp:
|
||
|
||
For a single-disk install only::
|
||
|
||
mkdir /boot/efi/grub /boot/grub
|
||
echo /boot/efi/grub /boot/grub none defaults,bind 0 0 >> /etc/fstab
|
||
mount /boot/grub
|
||
|
||
This allows GRUB to write to ``/boot/grub`` (since it is on a FAT-formatted
|
||
ESP instead of on ZFS), which means that ``/boot/grub/grubenv`` and the
|
||
``recordfail`` feature works as expected: if the boot fails, the normally
|
||
hidden GRUB menu will be shown on the next boot. For a mirror or raidz
|
||
topology, we do not want GRUB writing to the EFI System Partition. This is
|
||
because we duplicate it at install without a mechanism to update the copies
|
||
when the GRUB configuration changes (e.g. as the kernel is upgraded). Thus,
|
||
we keep ``/boot/grub`` on the boot pool for the mirror or raidz topologies.
|
||
This preserves correct mirroring/raidz behavior, at the expense of being
|
||
able to write to ``/boot/grub/grubenv`` and thus the ``recordfail``
|
||
behavior.
|
||
|
||
#. Install GRUB/Linux/ZFS in the chroot environment for the new system:
|
||
|
||
Choose one of the following options:
|
||
|
||
- Install GRUB/Linux/ZFS for legacy (BIOS) booting::
|
||
|
||
apt install --yes grub-pc linux-image-generic zfs-initramfs zsys
|
||
|
||
Select (using the space bar) all of the disks (not partitions) in your
|
||
pool.
|
||
|
||
- Install GRUB/Linux/ZFS for UEFI booting::
|
||
|
||
apt install --yes \
|
||
grub-efi-amd64 grub-efi-amd64-signed linux-image-generic \
|
||
shim-signed zfs-initramfs zsys
|
||
|
||
**Note:** For a mirror or raidz topology, this step only installs GRUB
|
||
on the first disk. The other disk(s) will be handled later. For some
|
||
reason, grub-efi-amd64 does not prompt for ``install_devices`` here, but
|
||
does after a reboot.
|
||
|
||
#. Optional: Remove os-prober::
|
||
|
||
dpkg --purge os-prober
|
||
|
||
This avoids error messages from ``update-grub``. ``os-prober`` is only
|
||
necessary in dual-boot configurations.
|
||
|
||
#. Set a root password::
|
||
|
||
passwd
|
||
|
||
#. Configure swap:
|
||
|
||
Choose one of the following options if you want swap:
|
||
|
||
- For an unencrypted single-disk install::
|
||
|
||
mkswap -f ${DISK}-part2
|
||
echo /dev/disk/by-uuid/$(blkid -s UUID -o value ${DISK}-part2) \
|
||
none swap discard 0 0 >> /etc/fstab
|
||
swapon -a
|
||
|
||
- For an unencrypted mirror or raidz topology::
|
||
|
||
apt install --yes mdadm
|
||
# Adjust the level (ZFS raidz = MD raid5, raidz2 = raid6) and
|
||
# raid-devices if necessary and specify the actual devices.
|
||
mdadm --create /dev/md0 --metadata=1.2 --level=mirror \
|
||
--raid-devices=2 ${DISK1}-part2 ${DISK2}-part2
|
||
mkswap -f /dev/md0
|
||
echo /dev/disk/by-uuid/$(blkid -s UUID -o value /dev/md0) \
|
||
none swap discard 0 0 >> /etc/fstab
|
||
|
||
- For an encrypted (LUKS or ZFS native encryption) single-disk install::
|
||
|
||
apt install --yes cryptsetup
|
||
echo swap ${DISK}-part2 /dev/urandom \
|
||
swap,cipher=aes-xts-plain64:sha256,size=512 >> /etc/crypttab
|
||
echo /dev/mapper/swap none swap defaults 0 0 >> /etc/fstab
|
||
|
||
- For an encrypted (LUKS or ZFS native encryption) mirror or raidz
|
||
topology::
|
||
|
||
apt install --yes cryptsetup mdadm
|
||
# Adjust the level (ZFS raidz = MD raid5, raidz2 = raid6) and
|
||
# raid-devices if necessary and specify the actual devices.
|
||
mdadm --create /dev/md0 --metadata=1.2 --level=mirror \
|
||
--raid-devices=2 ${DISK1}-part2 ${DISK2}-part2
|
||
echo swap /dev/md0 /dev/urandom \
|
||
swap,cipher=aes-xts-plain64:sha256,size=512 >> /etc/crypttab
|
||
echo /dev/mapper/swap none swap defaults 0 0 >> /etc/fstab
|
||
|
||
#. Optional (but recommended): Mount a tmpfs to ``/tmp``
|
||
|
||
If you chose to create a ``/tmp`` dataset above, skip this step, as they
|
||
are mutually exclusive choices. Otherwise, you can put ``/tmp`` on a
|
||
tmpfs (RAM filesystem) by enabling the ``tmp.mount`` unit.
|
||
|
||
::
|
||
|
||
cp /usr/share/systemd/tmp.mount /etc/systemd/system/
|
||
systemctl enable tmp.mount
|
||
|
||
#. Setup system groups::
|
||
|
||
addgroup --system lpadmin
|
||
addgroup --system lxd
|
||
addgroup --system sambashare
|
||
|
||
#. Patch a dependency loop:
|
||
|
||
For ZFS native encryption or LUKS::
|
||
|
||
sudo apt install --yes curl patch
|
||
|
||
curl https://launchpadlibrarian.net/478315221/2150-fix-systemd-dependency-loops.patch | \
|
||
sed "s|/etc|/lib|;s|\.in$||" | (cd / ; sudo patch -p1)
|
||
|
||
This patch is from `Bug #1875577 Encrypted swap won't load on 20.04 with
|
||
zfs root
|
||
<https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1875577>`__.
|
||
|
||
Step 5: GRUB Installation
|
||
-------------------------
|
||
|
||
#. Verify that the ZFS boot filesystem is recognized::
|
||
|
||
grub-probe /boot
|
||
|
||
#. Refresh the initrd files::
|
||
|
||
update-initramfs -c -k all
|
||
|
||
**Note:** When using LUKS, this will print “WARNING could not determine
|
||
root device from /etc/fstab”. This is because `cryptsetup does not
|
||
support ZFS
|
||
<https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1612906>`__.
|
||
|
||
#. Disable memory zeroing::
|
||
|
||
vi /etc/default/grub
|
||
# Add init_on_alloc=0 to: GRUB_CMDLINE_LINUX_DEFAULT
|
||
# Save and quit.
|
||
|
||
This is to address `performance regressions
|
||
<https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1862822>`__.
|
||
|
||
#. Optional (but highly recommended): Make debugging GRUB easier::
|
||
|
||
vi /etc/default/grub
|
||
# Comment out: GRUB_TIMEOUT_STYLE=hidden
|
||
# Set: GRUB_TIMEOUT=5
|
||
# Below GRUB_TIMEOUT, add: GRUB_RECORDFAIL_TIMEOUT=5
|
||
# Remove quiet and splash from: GRUB_CMDLINE_LINUX_DEFAULT
|
||
# Uncomment: GRUB_TERMINAL=console
|
||
# Save and quit.
|
||
|
||
Later, once the system has rebooted twice and you are sure everything is
|
||
working, you can undo these changes, if desired.
|
||
|
||
#. Update the boot configuration::
|
||
|
||
update-grub
|
||
|
||
**Note:** Ignore errors from ``osprober``, if present.
|
||
|
||
#. Install the boot loader:
|
||
|
||
Choose one of the following options:
|
||
|
||
- For legacy (BIOS) booting, install GRUB to the MBR::
|
||
|
||
grub-install $DISK
|
||
|
||
Note that you are installing GRUB to the whole disk, not a partition.
|
||
|
||
If you are creating a mirror or raidz topology, repeat the
|
||
``grub-install`` command for each disk in the pool.
|
||
|
||
- For UEFI booting, install GRUB to the ESP::
|
||
|
||
grub-install --target=x86_64-efi --efi-directory=/boot/efi \
|
||
--bootloader-id=ubuntu --recheck --no-floppy
|
||
|
||
#. Disable grub-initrd-fallback.service
|
||
|
||
For a mirror or raidz topology:
|
||
|
||
systemctl mask grub-initrd-fallback.service
|
||
|
||
This is the service for ``/boot/grub/grubenv`` which does not work on
|
||
mirrored or raidz topologies. Disabling this keeps it from blocking
|
||
subsequent mounts of ``/boot/grub`` if that mount ever fails.
|
||
|
||
Another option would be to set ``RequiresMountsFor=/boot/grub`` via a
|
||
drop-in unit, but that is more work to do here for no reason. Hopefully
|
||
`this bug <https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1881442>`__
|
||
will be fixed upstream.
|
||
|
||
#. Fix filesystem mount ordering:
|
||
|
||
We need to activate ``zfs-mount-generator``. This makes systemd aware of
|
||
the separate mountpoints, which is important for things like ``/var/log``
|
||
and ``/var/tmp``. In turn, ``rsyslog.service`` depends on ``var-log.mount``
|
||
by way of ``local-fs.target`` and services using the ``PrivateTmp`` feature
|
||
of systemd automatically use ``After=var-tmp.mount``.
|
||
|
||
::
|
||
|
||
mkdir /etc/zfs/zfs-list.cache
|
||
touch /etc/zfs/zfs-list.cache/bpool
|
||
touch /etc/zfs/zfs-list.cache/rpool
|
||
ln -s /usr/lib/zfs-linux/zed.d/history_event-zfs-list-cacher.sh /etc/zfs/zed.d
|
||
zed -F &
|
||
|
||
Verify that ``zed`` updated the cache by making sure these are not empty::
|
||
|
||
cat /etc/zfs/zfs-list.cache/bpool
|
||
cat /etc/zfs/zfs-list.cache/rpool
|
||
|
||
If either is empty, force a cache update and check again::
|
||
|
||
zfs set canmount=noauto bpool/BOOT/ubuntu_$UUID
|
||
zfs set canmount=noauto rpool/ROOT/ubuntu_$UUID
|
||
|
||
Stop ``zed``::
|
||
|
||
fg
|
||
Press Ctrl-C.
|
||
|
||
Fix the paths to eliminate ``/mnt``::
|
||
|
||
sed -Ei "s|/mnt/?|/|" /etc/zfs/zfs-list.cache/*
|
||
|
||
Step 6: First Boot
|
||
------------------
|
||
|
||
#. Optional: Install SSH::
|
||
|
||
apt install --yes openssh-server
|
||
|
||
vi /etc/ssh/sshd_config
|
||
# Set: PermitRootLogin yes
|
||
|
||
#. Exit from the ``chroot`` environment back to the LiveCD environment::
|
||
|
||
exit
|
||
|
||
#. Run these commands in the LiveCD environment to unmount all
|
||
filesystems::
|
||
|
||
mount | grep -v zfs | tac | awk '/\/mnt/ {print $3}' | \
|
||
xargs -i{} umount -lf {}
|
||
zpool export -a
|
||
|
||
#. Reboot::
|
||
|
||
reboot
|
||
|
||
Wait for the newly installed system to boot normally. Login as root.
|
||
|
||
#. Install GRUB to additional disks:
|
||
|
||
For a UEFI mirror or raidz topology only::
|
||
|
||
dpkg-reconfigure grub-efi-amd64
|
||
|
||
Select (using the space bar) all of the ESP partitions (partition 1 on
|
||
each of the pool disks).
|
||
|
||
#. Create a user account:
|
||
|
||
Replace ``username`` with your desired username::
|
||
|
||
UUID=$(dd if=/dev/urandom of=/dev/stdout bs=1 count=100 2>/dev/null |
|
||
tr -dc 'a-z0-9' | cut -c-6)
|
||
ROOT_DS=$(zfs list -o name | awk '/ROOT\/ubuntu_/{print $1;exit}')
|
||
zfs create -o com.ubuntu.zsys:bootfs-datasets=$ROOT_DS \
|
||
-o canmount=on -o mountpoint=/home/username \
|
||
rpool/USERDATA/username_$UUID
|
||
adduser username
|
||
|
||
cp -a /etc/skel/. /home/username
|
||
chown -R username:username /home/username
|
||
usermod -a -G adm,cdrom,dip,lpadmin,lxd,plugdev,sambashare,sudo username
|
||
|
||
Step 7: Full Software Installation
|
||
----------------------------------
|
||
|
||
#. Upgrade the minimal system::
|
||
|
||
apt dist-upgrade --yes
|
||
|
||
#. Install a regular set of software:
|
||
|
||
Choose one of the following options:
|
||
|
||
- Install a command-line environment only::
|
||
|
||
apt install --yes ubuntu-standard
|
||
|
||
- Install a full GUI environment::
|
||
|
||
apt install --yes ubuntu-desktop
|
||
vi /etc/gdm3/custom.conf
|
||
# In the [daemon] section, add: InitialSetupEnable=false
|
||
|
||
**Hint**: If you are installing a full GUI environment, you will likely
|
||
want to manage your network with NetworkManager::
|
||
|
||
rm /etc/netplan/01-netcfg.yaml
|
||
vi /etc/netplan/01-network-manager-all.yaml
|
||
|
||
.. code-block:: yaml
|
||
|
||
network:
|
||
version: 2
|
||
renderer: NetworkManager
|
||
|
||
#. Optional: Disable log compression:
|
||
|
||
As ``/var/log`` is already compressed by ZFS, logrotate’s compression is
|
||
going to burn CPU and disk I/O for (in most cases) very little gain. Also,
|
||
if you are making snapshots of ``/var/log``, logrotate’s compression will
|
||
actually waste space, as the uncompressed data will live on in the
|
||
snapshot. You can edit the files in ``/etc/logrotate.d`` by hand to comment
|
||
out ``compress``, or use this loop (copy-and-paste highly recommended)::
|
||
|
||
for file in /etc/logrotate.d/* ; do
|
||
if grep -Eq "(^|[^#y])compress" "$file" ; then
|
||
sed -i -r "s/(^|[^#y])(compress)/\1#\2/" "$file"
|
||
fi
|
||
done
|
||
|
||
#. Reboot::
|
||
|
||
reboot
|
||
|
||
Step 8: Final Cleanup
|
||
---------------------
|
||
|
||
#. Wait for the system to boot normally. Login using the account you
|
||
created. Ensure the system (including networking) works normally.
|
||
|
||
#. Optional: Disable the root password::
|
||
|
||
sudo usermod -p '*' root
|
||
|
||
#. Optional (but highly recommended): Disable root SSH logins:
|
||
|
||
If you installed SSH earlier, revert the temporary change::
|
||
|
||
vi /etc/ssh/sshd_config
|
||
# Remove: PermitRootLogin yes
|
||
|
||
systemctl restart ssh
|
||
|
||
#. Optional: Re-enable the graphical boot process:
|
||
|
||
If you prefer the graphical boot process, you can re-enable it now. If
|
||
you are using LUKS, it makes the prompt look nicer.
|
||
|
||
::
|
||
|
||
sudo vi /etc/default/grub
|
||
# Uncomment: GRUB_TIMEOUT_STYLE=hidden
|
||
# Add quiet and splash to: GRUB_CMDLINE_LINUX_DEFAULT
|
||
# Comment out: GRUB_TERMINAL=console
|
||
# Save and quit.
|
||
|
||
sudo update-grub
|
||
|
||
**Note:** Ignore errors from ``osprober``, if present.
|
||
|
||
#. Optional: For LUKS installs only, backup the LUKS header::
|
||
|
||
sudo cryptsetup luksHeaderBackup /dev/disk/by-id/scsi-SATA_disk1-part4 \
|
||
--header-backup-file luks1-header.dat
|
||
|
||
Store that backup somewhere safe (e.g. cloud storage). It is protected by
|
||
your LUKS passphrase, but you may wish to use additional encryption.
|
||
|
||
**Hint:** If you created a mirror or raidz topology, repeat this for each
|
||
LUKS volume (``luks2``, etc.).
|
||
|
||
Troubleshooting
|
||
---------------
|
||
|
||
Rescuing using a Live CD
|
||
~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
||
Go through `Step 1: Prepare The Install Environment
|
||
<#step-1-prepare-the-install-environment>`__.
|
||
|
||
For LUKS, first unlock the disk(s)::
|
||
|
||
cryptsetup luksOpen /dev/disk/by-id/scsi-SATA_disk1-part4 luks1
|
||
# Repeat for additional disks, if this is a mirror or raidz topology.
|
||
|
||
Mount everything correctly::
|
||
|
||
zpool export -a
|
||
zpool import -N -R /mnt rpool
|
||
zpool import -N -R /mnt bpool
|
||
zfs load-key -a
|
||
# Replace “UUID” as appropriate; use zfs list to find it:
|
||
zfs mount rpool/ROOT/ubuntu_UUID
|
||
zfs mount bpool/BOOT/ubuntu_UUID
|
||
zfs mount -a
|
||
|
||
If needed, you can chroot into your installed environment::
|
||
|
||
mount --rbind /dev /mnt/dev
|
||
mount --rbind /proc /mnt/proc
|
||
mount --rbind /sys /mnt/sys
|
||
chroot /mnt /bin/bash --login
|
||
mount -a
|
||
|
||
Do whatever you need to do to fix your system.
|
||
|
||
When done, cleanup::
|
||
|
||
exit
|
||
mount | grep -v zfs | tac | awk '/\/mnt/ {print $3}' | \
|
||
xargs -i{} umount -lf {}
|
||
zpool export -a
|
||
reboot
|
||
|
||
Areca
|
||
~~~~~
|
||
|
||
Systems that require the ``arcsas`` blob driver should add it to the
|
||
``/etc/initramfs-tools/modules`` file and run ``update-initramfs -c -k all``.
|
||
|
||
Upgrade or downgrade the Areca driver if something like
|
||
``RIP: 0010:[<ffffffff8101b316>] [<ffffffff8101b316>] native_read_tsc+0x6/0x20``
|
||
appears anywhere in kernel log. ZoL is unstable on systems that emit this
|
||
error message.
|
||
|
||
MPT2SAS
|
||
~~~~~~~
|
||
|
||
Most problem reports for this tutorial involve ``mpt2sas`` hardware that does
|
||
slow asynchronous drive initialization, like some IBM M1015 or OEM-branded
|
||
cards that have been flashed to the reference LSI firmware.
|
||
|
||
The basic problem is that disks on these controllers are not visible to the
|
||
Linux kernel until after the regular system is started, and ZoL does not
|
||
hotplug pool members. See `https://github.com/zfsonlinux/zfs/issues/330
|
||
<https://github.com/zfsonlinux/zfs/issues/330>`__.
|
||
|
||
Most LSI cards are perfectly compatible with ZoL. If your card has this
|
||
glitch, try setting ``ZFS_INITRD_PRE_MOUNTROOT_SLEEP=X`` in
|
||
``/etc/default/zfs``. The system will wait ``X`` seconds for all drives to
|
||
appear before importing the pool.
|
||
|
||
QEMU/KVM/XEN
|
||
~~~~~~~~~~~~
|
||
|
||
Set a unique serial number on each virtual disk using libvirt or qemu
|
||
(e.g. ``-drive if=none,id=disk1,file=disk1.qcow2,serial=1234567890``).
|
||
|
||
To be able to use UEFI in guests (instead of only BIOS booting), run
|
||
this on the host::
|
||
|
||
sudo apt install ovmf
|
||
sudo vi /etc/libvirt/qemu.conf
|
||
|
||
Uncomment these lines:
|
||
|
||
.. code-block:: text
|
||
|
||
nvram = [
|
||
"/usr/share/OVMF/OVMF_CODE.fd:/usr/share/OVMF/OVMF_VARS.fd",
|
||
"/usr/share/OVMF/OVMF_CODE.secboot.fd:/usr/share/OVMF/OVMF_VARS.fd",
|
||
"/usr/share/AAVMF/AAVMF_CODE.fd:/usr/share/AAVMF/AAVMF_VARS.fd",
|
||
"/usr/share/AAVMF/AAVMF32_CODE.fd:/usr/share/AAVMF/AAVMF32_VARS.fd",
|
||
"/usr/share/OVMF/OVMF_CODE.ms.fd:/usr/share/OVMF/OVMF_VARS.ms.fd"
|
||
]
|
||
|
||
::
|
||
|
||
sudo systemctl restart libvirtd.service
|
||
|
||
VMware
|
||
~~~~~~
|
||
|
||
- Set ``disk.EnableUUID = "TRUE"`` in the vmx file or vsphere configuration.
|
||
Doing this ensures that ``/dev/disk`` aliases are created in the guest.
|