Debian/Ubuntu: Add Ubuntu 20.04

I have backported some of the cosmetic and other minimal changes to Ubuntu 18.04 and Debian Buster. This keeps the deltas as small as reasonably possible. Signed-off-by: Richard Laager <rlaager@wiktel.com>
2020-05-24 02:38:49 -05:00
parent 417c2a5379
commit 7c4861e911
5 changed files with 1280 additions and 190 deletions
--- a/Started/Debian/Debian
+++ b/Started/Debian/Debian
@@ -23,7 +23,7 @@ System Requirements
  iso) <https://cdimage.debian.org/mirror/cdimage/release/current-live/amd64/iso-hybrid/>`__
 - `A 64-bit kernel is strongly
  encouraged. <https://github.com/zfsonlinux/zfs/wiki/FAQ#32-bit-vs-64-bit-systems>`__
- Installing on a drive which presents 4KiB logical sectors (a “4Kn”
+- 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. <http://savannah.gnu.org/bugs/?46700>`__
@@ -39,7 +39,7 @@ Support

 If you need help, reach out to the community using the :doc:`zfs-discuss
 mailing list <../../Project and Community/Mailing Lists>` or IRC at
-`#zfsonlinux <irc://irc.freenode.net/#zfsonlinux>`__. on `freenode
+`#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%20Debian%20Buster%20Root%20on%20ZFS%20HOWTO:>`__.
@@ -74,20 +74,13 @@ Contributing
 Encryption
 ~~~~~~~~~~

-This guide supports three different encryption options: unencrypted,
-LUKS (full-disk encryption), and ZFS native encryption. With any option,
-all ZFS features are fully available.
+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.

-LUKS encrypts almost everything: the OS, swap, home directories, and
-anything else. 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.
-
 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,
@@ -97,6 +90,12 @@ 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
 ---------------------------------------

@@ -212,12 +211,7 @@ commands for all the disks which will be part of the pool.
      -o feature@large_blocks=enabled \
      -o feature@lz4_compress=enabled \
      -o feature@spacemap_histogram=enabled \
-      -o feature@userobj_accounting=enabled \
      -o feature@zpool_checkpoint=enabled \
-      -o feature@spacemap_v2=enabled \
-      -o feature@project_quota=enabled \
-      -o feature@resilver_defer=enabled \
-      -o feature@allocation_classes=enabled \
      -O acltype=posixacl -O canmount=off -O compression=lz4 -O devices=off \
      -O normalization=formD -O relatime=on -O xattr=sa \
      -O mountpoint=/ -R /mnt bpool ${DISK}-part3
@@ -230,7 +224,7 @@ GRUB does not support all of the zpool features. See
 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.
+read-only compatible features are “supported” by GRUB.

 **Hints:**

@@ -241,6 +235,24 @@ read-only compatible features are "supported" by GRUB.
 - The pool name is arbitrary. If changed, the new name must be used
  consistently. The ``bpool`` convention originated in this HOWTO.

+**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.
+
 2.5 Create the root pool:

 Choose one of the following options:
@@ -252,7 +264,15 @@ Choose one of the following options:
      -O dnodesize=auto -O normalization=formD -O relatime=on -O xattr=sa \
      -O mountpoint=/ -R /mnt rpool ${DISK}-part4

-2.5b LUKS::
+2.5b ZFS native encryption::
+
+  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 encryption=aes-256-gcm -O keylocation=prompt -O keyformat=passphrase \
+      -O mountpoint=/ -R /mnt rpool ${DISK}-part4
+
+2.5c LUKS::

  apt install --yes cryptsetup
  cryptsetup luksFormat -c aes-xts-plain64 -s 512 -h sha256 ${DISK}-part4
@@ -262,22 +282,16 @@ Choose one of the following options:
      -O dnodesize=auto -O normalization=formD -O relatime=on -O xattr=sa \
      -O mountpoint=/ -R /mnt rpool /dev/mapper/luks1

-2.5c ZFS native encryption::
-
-  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 encryption=aes-256-gcm -O keylocation=prompt -O keyformat=passphrase \
-      -O mountpoint=/ -R /mnt rpool ${DISK}-part4
+**Notes:**

 - The use of ``ashift=12`` is recommended here because many drives
-  today have 4KiB (or larger) physical sectors, even though they
-  present 512B logical sectors. Also, a future replacement drive may
-  have 4KiB physical sectors (in which case ``ashift=12`` is desirable)
-  or 4KiB logical sectors (in which case ``ashift=12`` is required).
+  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``
+  ``-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>`__
 - Setting ``normalization=formD`` eliminates some corner cases relating
@@ -287,11 +301,18 @@ Choose one of the following options:
  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
+  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
@@ -314,16 +335,17 @@ Choose one of the following options:
 - 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.
- ZFS native encryption uses ``aes-256-ccm`` by default. `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>`__.
 - 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>`__
@@ -351,9 +373,10 @@ Step 3: System Installation

 On Solaris systems, the root filesystem is cloned and the suffix is
 incremented for major system changes through ``pkg image-update`` or
-``beadm``. Similar functionality for APT is possible but currently
-unimplemented. Even without such a tool, it can still be used for
-manually created clones.
+``beadm``. Similar functionality has been implemented in Ubuntu 20.04 with the
+``zsys`` tool, though its dataset layout is more complicated. Even without
+such a tool, the `rpool/ROOT` and `bpool/BOOT` containers can still be used
+for manually created clones.

 3.2 Create filesystem datasets for the root and boot filesystems::

@@ -428,17 +451,15 @@ If this system will use NFS (locking)::
  zfs create -o com.sun:auto-snapshot=false  rpool/var/lib/nfs

 A tmpfs is recommended later, but if you want a separate dataset for
-/tmp::
+``/tmp``::

  zfs create -o com.sun:auto-snapshot=false  rpool/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 such as logs (in ``/var/log``). This will be especially
-important if/when a ``beadm`` or similar utility is integrated. The
-``com.sun.auto-snapshot`` setting is used by some ZFS snapshot utilities
-to exclude transient data.
+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. The ``com.sun.auto-snapshot`` setting is used by some ZFS
+snapshot utilities to exclude transient data.

 If you do nothing extra, ``/tmp`` will be stored as part of the root
 filesystem. Alternatively, you can create a separate dataset for
@@ -459,8 +480,9 @@ of a working system into the new ZFS root.
 Step 4: System Configuration
 ----------------------------

-4.1 Configure the hostname (change ``HOSTNAME`` to the desired
-hostname)::
+4.1 Configure the hostname:
+
+Replace ``HOSTNAME`` with the desired hostname::

  echo HOSTNAME > /mnt/etc/hostname
  vi /mnt/etc/hosts
@@ -491,9 +513,7 @@ Adjust NAME below to match your interface name::

 Customize this file if the system is not a DHCP client.

-4.3 Configure the package sources:
-
-::
+4.3 Configure the package sources::

  vi /mnt/etc/apt/sources.list

@@ -550,16 +570,15 @@ Even if you prefer a non-English system language, always ensure that
  apt install --yes zfs-initramfs
  echo REMAKE_INITRD=yes > /etc/dkms/zfs.conf

-4.7 For LUKS installs only, setup crypttab::
+4.7 For LUKS installs only, setup ``/etc/crypttab``::

  apt install --yes cryptsetup

  echo luks1 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>`__.
+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.
@@ -572,7 +591,7 @@ Choose one of the following options:

  apt install --yes grub-pc

-Install GRUB to the disk(s), not the partition(s).
+Select (using the space bar) all of the disks (not partitions) in your pool.

 4.8b Install GRUB for UEFI booting::

@@ -584,20 +603,27 @@ Install GRUB to the disk(s), not the partition(s).
  mount /boot/efi
  apt install --yes grub-efi-amd64 shim-signed

- 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.
+**Notes:**

-**Note:** If you are creating a mirror or raidz topology, this step only
-installs GRUB on the first disk. The other disk(s) will be handled
-later.
+- 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.
+- For a mirror or raidz topology, this step only installs GRUB on the
+  first disk. The other disk(s) will be handled later.

-4.9 Set a root password::
+4.9 (Optional): Remove os-prober::
+
+    dpkg --purge os-prober
+
+This avoids error messages from `update-grub`.  `os-prober` is only necessary
+in dual-boot configurations.
+
+4.10 Set a root password::

  passwd

-4.10 Enable importing bpool
+4.11 Enable importing bpool

 This ensures that ``bpool`` is always imported, regardless of whether
 ``/etc/zfs/zpool.cache`` exists, whether it is in the cachefile or not,
@@ -626,7 +652,7 @@ or whether ``zfs-import-scan.service`` is enabled.

  systemctl enable zfs-import-bpool.service

-4.11 Optional (but recommended): Mount a tmpfs to /tmp
+4.12 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
@@ -637,7 +663,7 @@ tmpfs (RAM filesystem) by enabling the ``tmp.mount`` unit.
  cp /usr/share/systemd/tmp.mount /etc/systemd/system/
  systemctl enable tmp.mount

-4.12 Optional (but kindly requested): Install popcon
+4.13 Optional (but kindly requested): Install popcon

 The ``popularity-contest`` package reports the list of packages install
 on your system. Showing that ZFS is popular may be helpful in terms of
@@ -658,12 +684,12 @@ Step 5: GRUB Installation

 5.2 Refresh the initrd files::

-  update-initramfs -u -k all
+  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>`__.
+**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>`__.

 5.3 Workaround GRUB's missing zpool-features support::

@@ -686,7 +712,7 @@ working, you can undo these changes, if desired.

 **Note:** Ignore errors from ``osprober``, if present.

-5.6 Install the boot loader
+5.6 Install the boot loader:

 5.6a For legacy (BIOS) booting, install GRUB to the MBR::

@@ -705,11 +731,7 @@ If you are creating a mirror or raidz topology, repeat the
 It is not necessary to specify the disk here. If you are creating a
 mirror or raidz topology, the additional disks will be handled later.

-5.7 Verify that the ZFS module is installed::
-
-  ls /boot/grub/*/zfs.mod
-
-5.8 Fix filesystem mount ordering
+5.7 Fix filesystem mount ordering:

 Until there is support for mounting ``/boot`` in the initramfs, we also
 need to mount that, because it was marked ``canmount=noauto``. Also,
@@ -738,7 +760,7 @@ Everything else applies to both BIOS and UEFI booting::
  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 this is not empty::
+Verify that ``zed`` updated the cache by making sure this is not empty::

  cat /etc/zfs/zfs-list.cache/rpool

@@ -746,12 +768,12 @@ If it is empty, force a cache update and check again::

  zfs set canmount=noauto rpool/ROOT/debian

-Stop zed::
+Stop ``zed``::

  fg
  Press Ctrl-C.

-Fix the paths to eliminate /mnt::
+Fix the paths to eliminate ``/mnt``::

  sed -Ei "s|/mnt/?|/|" /etc/zfs/zfs-list.cache/rpool

@@ -781,32 +803,31 @@ filesystems::

  reboot

-6.5 Wait for the newly installed system to boot normally. Login as root.
+Wait for the newly installed system to boot normally. Login as root.

-6.6 Create a user account::
+6.5 Create a user account:

-  zfs create rpool/home/YOURUSERNAME
-  adduser YOURUSERNAME
-  cp -a /etc/skel/. /home/YOURUSERNAME
-  chown -R YOURUSERNAME:YOURUSERNAME /home/YOURUSERNAME
+Replace ``username`` with your desired username::

-6.7 Add your user account to the default set of groups for an
-administrator::
+  zfs create rpool/home/username
+  adduser username

-  usermod -a -G audio,cdrom,dip,floppy,netdev,plugdev,sudo,video YOURUSERNAME
+  cp -a /etc/skel/. /home/username
+  chown -R username:username /home/username
+  usermod -a -G audio,cdrom,dip,floppy,netdev,plugdev,sudo,video username

-6.8 Mirror GRUB
+6.6 Mirror GRUB

 If you installed to multiple disks, install GRUB on the additional
 disks:

-6.8a For legacy (BIOS) booting::
+6.6a For legacy (BIOS) booting::

  dpkg-reconfigure grub-pc
  Hit enter until you get to the device selection screen.
  Select (using the space bar) all of the disks (not partitions) in your pool.

-6.8b For UEFI booting::
+6.6b For UEFI booting::

  umount /boot/efi

@@ -992,8 +1013,8 @@ 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
+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.

 Areca
@@ -1001,7 +1022,7 @@ Areca

 Systems that require the ``arcsas`` blob driver should add it to the
 ``/etc/initramfs-tools/modules`` file and run
-``update-initramfs -u -k all``.
+``update-initramfs -c -k all``.

 Upgrade or downgrade the Areca driver if something like
 ``RIP: 0010:[<ffffffff8101b316>]  [<ffffffff8101b316>] native_read_tsc+0x6/0x20``