Skill: Advanced, Complexity: Significant, Est Time To Complete: ~3 Hours, Tested Ubuntu Versions: 13.04 64bit Raring Ringtail (Desktop)

Encrypted ZFS Ubuntu Installation

You know all the goodness ZFS provides. You know all the goodness Ubuntu provides. You know all the goodness LUKS whole disk encryption provides. That is why you are here.

This 'howto' is primarily directed at laptop/desktop users but by extension is easily suited for Ubuntu server installations.

Most of the heavy lifting was provided by Metal-Head at LarskoOrg. A great deal of insight and direction was gleened from the ZFS on Linux community and the Oracle Solaris ZFS Administration Guide


Prerequisites

  • Ubuntu 64bit operating system (ZFS will NOT run with any reliability on 32bit systems)
  • CPU(s) with AES capabilities (lshw to show the cpu capabilities and confirm aes). You can utilize cpus without the AES capabilities but you will incur a performance penalty. Reports are ~20% decrease in throughput.

  • Adequate host RAM
  • Storage with ~20% or more free space after installation and data migration
  • Strong passphrases

  • 8GB USB flash drive (preferably USB 3.0 capable flash drive). You can substitute the flash drive for any other temporary storage device. e.g. ~8GB disk partition on target root disk that can be re-purposed, a secondary HDD/SSD, etc.
  • Internet connectivity
  • Ubuntu LiveCD on a bootable CD/DVD/USB device.


Caveats

ZFS Integrity When Using LUKS

There is some debate on the limitations of ZFS on LUKS suggesting that to fully realize the benefits of ZFS, encrypted file systems should be layered on top of ZFS. From my research ZFS on LUKS has not demonstrated any problems with ZFS integrity. Additionaly, LUKS block device encryption is purported to have better performance metrics over stacked filesystem encryption like eCryptfs.

Hibernation

I have not documented a mechanism to support hibernation. This configuration will support suspend. Supporting hibernation would require a seperate partition equal to or greater than physical RAM. It could be a LUKS container or LUKS container with a ZFS Volume.

UEFI Booting

This guide will need to be adjusted to support UEFI booting. Most notable would be creating an unencrypted /boot/efi 1MB partition (which will be vfat), unencrypted /boot 512MB partition and then encrypted / partition.


Tested Environment

  • (1) SSD 256GB, msdos disk label, 2 partitions

    • [1] /boot with boot flag set, 512MB

    • [2] for ZFS on LUKS /

  • (3) HDD +1TB, gpt disk label, 1 partition per disk

    • [1] LUKS container (to be member of RAIDZ additional storage pool)
  • Intel i7 CPU with AES capabilities
  • 16GB RAM
  • Swap added as a ZFS VOL

This was also tested with an Ubuntu virtual machine to experiment, test, stress and solidfy this installation procedure. I strongly suggest using spare equipment or a virtual machine instance if you are new to ZFS or LUKS encryption.


ZFS on LUKS Installation

Boot LiveCD

Boot to Ubuntu LiveCD, open a terminal and sudo to root. ALT-F1, enter, and search for 'terminal' or Windows Start Key, and search for 'terminal'. All command references assume you are root for this process.

sudo -i

Configure Storage

Zero out the storage devices, label and partition.

SSD 256GB (/dev/sda)


dd if=/dev/zero of=/dev/sda bs=1M count=10

parted -a optimal /dev/sda
mklabel msdos
unit MB
mkpart primary 1 513
mkpart primary 513 -1
toggle 1 boot

HDD(s) (/dev/sd?)


Repeat for each additional storage device, substituting sd? with your storage ID. e.g. sdb, sdc, sdd, ...

dd if=/dev/zero of=/dev/sd? bs=1M count=10

parted -a optimal /dev/sd?
mklabel gpt
unit MB
mkpart vpool 1 -1

Install Ubuntu

Install Ubuntu onto the 8GB USB storage or other temporary storage volume. You can skip providing a swap partition and my also install Ubuntu in its entirety to a single / partition. Select 'download updates during installation' and '3rd party applications' as desired.

When installation is complete be sure to select "CONTINUE TESTING".

Install ZFS Packages

While still in the live environment install the ZFS repository and ubuntu-zfs packages. This will take some time to install and compile the DKMS ZFS modules for the running kernel.

apt-add-repository --yes ppa:zfs-native/stable
apt-get update
apt-get -y install ubuntu-zfs

Create LUKS Containers

Create the LUKS containers using best practices for robust encryption. The aes-xts-plain64 is highly recommended as it supports volumes greater than 2TB and is very robust. Follow the prompts. Assure that you are using a strong passphrase. sda2 is the / root partitiion. sdb1, sdc1, sdd1 are for the additional RAIDZ storage volume. Repeat this step for any additional volumes sd?.

If you are adventuresome, or have iterated through this process a number of times, you can open another terminal tab CTRL-SHIFT-T, sudo -i and create the LUKS containers while the ubuntu-zfs packages are installing and compiling. Otherwise wait until the previous step is completed.

cryptsetup luksFormat -c aes-xts-plain64 -s 512 -h sha512 /dev/sda2
cryptsetup luksFormat -c aes-xts-plain64 -s 512 -h sha512 /dev/sdb1
cryptsetup luksFormat -c aes-xts-plain64 -s 512 -h sha512 /dev/sdc1
cryptsetup luksFormat -c aes-xts-plain64 -s 512 -h sha512 /dev/sdd1
(repeat for each additional luks container) ...

Open LUKS Containers

Once the LUKS containers have been created. Open them. Provide unique names. For other storage containers that will be used in a RAIDZ configuration a serialized set of <unique_name> is suggested. e.g. s1_crypt, s2_crypt ... etc.

cryptsetup luksOpen /dev/sda2 root_crypt
cryptsetup luksOpen /dev/sdb1 vault1_crypt
cryptsetup luksOpen /dev/sdc1 vault2_crypt
cryptsetup luksOpen /dev/sdd1 vault3_crypt
(repeat for each additional luks container) ...

Once complete, you can affirm the containers are opened with ls /dev/mapper. The LUKS container names that you provided should be listed.

Add Derived LUKS Keys

To avoid multiple passphrase prompts at boot time for unlocking all the LUKS containers, add the derived key for the root_crypt container to the other LUKS containers. This derived key will be generated from the root_crypt container in the initramfs at boot time. Obtaining the derived key from root_crypt at boot is covered in later sections. Using a derived key is relatively secure since it can only be generated after the root_crypt container has been opened with the proper passphrase.

/lib/cryptsetup/scripts/decrypt_derived root_crypt > /tmp/key

cryptsetup luksAddKey /dev/sdb1 /tmp/key
cryptsetup luksAddKey /dev/sdc1 /tmp/key
cryptsetup luksAddKey /dev/sdd1 /tmp/key
(repeat for each additional luks container) ...

If the master key for the LUKS container root_crypt ever changes you will need to add the new derived master key to the other LUKS containers again.

Backup LUKS Headers (optional)


!! BACKUP EACH LUKS CONTAINERS HEADER FOR PROTECTION !! While optional, this is highly recommended.

Follow the procedure at ArchLinux-LUKS-Backup

cryptsetup luksHeaderBackup /dev/sda2 --header-backup-file <pathToSave>/luks_sda2_header_backup
cryptsetup luksHeaderBackup /dev/sdb1 --header-backup-file <pathToSave>/luks_sdb1_header_backup
cryptsetup luksHeaderBackup /dev/sdc1 --header-backup-file <pathToSave>/luks_sdc1_header_backup
cryptsetup luksHeaderBackup /dev/sdd1 --header-backup-file <pathToSave>/luks_sdd1_header_backup
(repeat for each additional luks container) ...

Create File Systems

Create /boot File System


I chose ext4 with 0% reserved blocks. Use the filesystem of your choosing. This /boot partition must not be encrypted and will contain the boot images and grub configuration.

mkfs.ext4 -m 0 -L /boot -j /dev/sda1

Create ZFS Pools


root_crypt will service the / partition and vault_crypt is the 'other' storage pool for miscellaneous content.

!! IT IS IMPERATIVE THAT THE root POOL BE NAMED rpool !! Other naming conventions will not properly boot. (I know. I tried. It failed). Pool names for anything else are abitrary. Use ashift=12 to support the newer storage devices with 4096K sectors. Use ashift=9 for older storage devices using the smaller 512K sectors.

zpool create -O mountpoint=none -o ashift=12 rpool /dev/mapper/root_crypt
zpool create -O mountpoint=none -o ashift=12 vpool raidz /dev/mapper/vault1_crypt /dev/mapper/vault2_crypt /dev/mapper/vault3_crypt

Create ZFS Datasets


I'm using compression. The lz4 compression is fast and clever. It will compress compressable content and skip uncompressable content. HDD read performance is increased and storage utilization is decreased (for compressable content). Compression MUST be set before you poplulate the dataset to assure all compressable content is compressed. You can enable compression later, but any prior content put into the dataset will remain uncompressed. The dataset names are arbitrary and can be changed to suit your purposes.

zfs create -o compression=lz4 rpool/ROOT
zfs create -o compression=lz4 vpool/VAULT

For an added performance tweak, disable atime; unless of course your applications rely on the access times.

zfs set atime=off rpool/ROOT
zfs set atime=off vpool/VAULT

Create ZFS Volume for SWAP


I have not dedicated a specific storage partition for SWAP. Instead create a ZFS volume that will be used for SWAP. This configuration will not support hibernation. (see caveat above). Replace -V 1024M with the sizing that is right for you. I use less swap space as the host has significant physical RAM capacity. This volume setting is courtesy of ArchLinux-ZFS-SwapVolume. The auto-snapshot=false will prevent this dataset from being included in any automated snapshots. See zfs-auto-snapshot later in the guide.

zfs create -V 1024M -b $(getconf PAGESIZE) \
              -o compression=off \
              -o primarycache=metadata \
              -o secondarycache=none \
              -o sync=always \
              -o com.sun:auto-snapshot=false rpool/SWAP

Prepare ZFS Mountpoints


This will set the ZFS dataset mountpoints. They do not get listed in /etc/fstab in the traditional sense. For datasets other than rpool/ROOT you can set the mountpoint to service your environment.

zfs set mountpoint=/ rpool/ROOT
zfs set mountpoint=/vault vpool/VAULT

Importantly, this step identifies the boot file system in the ZFS pool.

zpool set bootfs=rpool/ROOT rpool

Export the pools so they can be re-imported to a temporary mount point.

zpool export rpool
zpool export vpool

Re-import the ZFS pools to a temporary mount point in the Ubuntu LiveCD environment. The mountpoints /mnt/zfs are arbitrary. The temporary mount mounts will become the chroot target. This target will be populated with the previously installed Ubuntu 8GB volume contents.

zpool import -d /dev/mapper -R /mnt/zfs rpool
zpool import -d /dev/mapper -R /mnt/zfs vpool

Mount Ubuntu Installation

Mount the Ubuntu installation that was installed on the temporary 8GB storage volume. Replace /dev/sd? with the 8GB temporary storage label.

mkdir /mnt/raring
mount /dev/sd? /mnt/raring

Copy Ubuntu Installation

Create a boot directory in the previously mounted ZFS dataset and mount the real target /dev/sd? storage partition onto it. In my case sda1.

mkdir /mnt/zfs/boot
mount /dev/sda1 /mnt/zfs/boot

Copy the Ubuntu installation from the temporary storage to the ZFS datasets.

cd /mnt/raring
tar cfp - . | ( cd /mnt/zfs/; tar xvfp -)

You may likely need to copy the current live environment resolv.conf into the ZFS dataset so that networking will function once you chroot into the ZFS dataset. When you chroot into the ZFS dataset and you can't host www.google.com you'll need to perform this step.

cp /etc/resolv.conf /mnt/zfs/etc/resolv.conf

Once the TAR create/extract is complete, un-mount the temporary Ubuntu installation to keep on hand if this process needs to be repeated.

umount /mnt/raring

CHROOT Into Target ZFS Environment

Mount the system references.

mount -o bind /proc /mnt/zfs/proc
mount -o bind /dev /mnt/zfs/dev
mount -o bind /dev/pts /mnt/zfs/dev/pts
mount -o bind /sys /mnt/zfs/sys

Change root and pivot onto the ZFS environment which now contains a complete copy of the previous Ubuntu installation.

chroot /mnt/zfs /bin/bash --login

Setup ZFS in CHROOT Environment


Set the hostid (which doesn't exist). Without it the ubuntu-zfs installation and compile will error. You will be prompted later to overwrite it with the maintainers package version. You may choose to do so or not.

hostid > /etc/hostid

Preapre a symbolic link to the root LUKS container. Without this symbolic link update-grub will complain that is can't find the canonical path and error. (Replace root_crypt with your named root LUKS container).

ln -s /dev/mapper/root_crypt /dev/root_crypt

Assure that future kernel updates will succeed by always creating the symbolic link. (Replace root_crypt with your named root LUKS container).

echo 'ENV{DM_NAME}=="root_crypt", SYMLINK+="root_crypt"' > /etc/udev/rules.d/99-local.rules

Install the ubuntu-zfs packages. This will take some time to install and compile the DKMS ZFS modules for the current kernel. cryptsetup must be installed in the chroot environment has it was not installed previously. zfs-initramfs is required to put the ZFS utilities for managing ZFS file systems in the initramfs booting images. I intentionally did not install the zfs-native/grub packages.

apt-add-repository --yes ppa:zfs-native/stable
apt-get update
apt-get -y install ubuntu-zfs zfs-initramfs cryptsetup

Create FSTAB Entries


Delete or comment out the previous Ubuntu installations fstab references in /etc/fstab. Add the following new entries. It looks a bit odd at first but /dev/mapper/root_crypt (or whatever 'root' LUKS container name you used) must be listed in the fstab for cryptsetup and the zfs utilities to pivot to rpool/ROOT on boot.

vi /etc/fstab

/dev/sda1               /boot   auto    defaults        0 0
/dev/mapper/root_crypt  /       zfs     defaults        0 0
/dev/zvol/rpool/SWAP    none    swap    defaults        0 0

Create `/etc/crypttab` Entries


Get the UUID of the block device that the /dev/mapper/root_crypt was created. (In this case /dev/sda2)

blkid
...
/dev/sda2: UUID="94581034-2545-2c1e-93bf-f89ab32b9d8e" TYPE="crypto_LUKS" 
...

To allow cryptsetup to properly identify the root LUKS container during update-initramfs add this entry to /etc/crypttab. This file did not previously exist. Use the UUID you just retrieved without quotes. (You could use /dev/sd? naming conventions, but using UUID's will assure consistent behavior). discard is added here to pass the TRIM commands to the SSD.

vi /etc/crypttab

root_crypt UUID=<uuid-/dev/sd?-root_crypt-crypto_LUKS-no-quotes> none luks,discard

Create `/etc/initramfs-tools/conf.d/cryptroot` Entries


For cryptsetup to properly identify the LUKS containers to unlock at boot time pick one of these entries; multiple or single passphrase prompts. Note that vault_crypt was not listed in /etc/crypttab. It is not necessary in that file. /etc/crypttab is largely referenced after the pivot from the initramfs to the 'real' root. All LUKS containers that need to be unlocked for ZFS MUST be listed in this file. Get the UUID for each crypto_LUKS container with blkid as before. The file MUST be named cryptroot as the cryptsetup routines reference that file explicitly. If named differently, cryptsetup will not identify the LUKS containers to unlock.


Single: If you want a single passphrase prompt, use this configuration. This file did not previously exist.

Get the derived master key. The root_crypt LUKS container must be open. Add the derived key to each LUKS container that you want to unlock at boot.

/lib/cryptsetup/scripts/decrypt_derived root_crypt > /tmp/key
cryptsetup luksAddKey /dev/sdb1 /tmp/key
cryptsetup luksAddKey /dev/sdc1 /tmp/key
cryptsetup luksAddKey /dev/sdd1 /tmp/key
(repeat for each additional luks container) ...

Copy the decrypt_derived shell script into the initramfs-tools so that it will be available in the initramfs boot environment.

mkdir /etc/initramfs-tools/scripts/luks
cp /lib/cryptsetup/scripts/decrypt_derived /etc/initramfs-tools/scripts/luks/get.root_crypt.decrypt_derived

Adapt the get.root_crypt.decrypt_derived shell script to fetch the master key without arguments.

vi /etc/initramfs-tools/scripts/luks/get.root_crypt.decrypt_derived

Add to top of /etc/initramfs-tools/scripts/luks/get.root_crypt.decrypt_derived

CRYPT_DEVICE=root_crypt

Then replace $1 with the new variable.

:1,$s/\$1/\$CRYPT_DEVICE/gc

Write out and quit.

:wq

Create cryptroot to be referenced in the boot image.

vi /etc/initramfs-tools/conf.d/cryptroot

Note: I was unable to find a way to define key=root_crypt,keyscript=/scripts/luks/decrypt_derived for vault#_crypt and have the 'key' passed to the script as it does with /etc/crypttab behavior.

target=root_crypt,source=UUID=<uuid-/dev/sd?-root_crypt-crypto_LUKS--no-quotes>,key=none,rootdev,discard
target=vault_crypt,source=UUID=<uuid-/dev/sd?-vault1_crypt-crypt_LUKS-no-quotes>,keyscript=/scripts/luks/get.root_crypt.decrypt_derived
target=vault_crypt,source=UUID=<uuid-/dev/sd?-vault2_crypt-crypto_LUKS-no-quotes>,keyscript=/scripts/luks/get.root_crypt.decrypt_derived
target=vault_crypt,source=UUID=<uuid-/dev/sd?-vault3_crypt-crypto_LUKS-no-quotes>,keyscript=/scripts/luks/get.root_crypt.decrypt_derived
(repeat for each additional luks container) ...


Multiple: At boot you will be prompted for passphrases for each LUKS container.

target=root_crypt,source=UUID=<uuid-/dev/sd?-root_crypt-crypt_LUKS-no-quotes>,key=none,rootdev,discard
target=vault_crypt,source=UUID=<uuid-/dev/sd?-vault1_crypt-crypto_LUKS-no-quotes>,key=none
target=vault_crypt,source=UUID=<uuid-/dev/sd?-vault2_crypt-crypto_LUKS-no-quotes>,key=none
target=vault_crypt,source=UUID=<uuid-/dev/sd?-vault3_crypt-crypto_LUKS-no-quotes>,key=none
(repeat for each additional luks container) ...

Add `boot=zfs` to GRUB


Perhaps because I did not install the zfs-native/grub packages, you must add boot=zfs to the grub.cfg stanzas. You MUST have boot=zfs in the linux line. If it is absent Ubuntu will not boot.

vi /etc/default/grub

Add boot=zfs to the default grub configuration file.

GRUB_CMDLINE_LINUX_DEFAULT="boot=zfs quiet splash"

Until certain that everything is working - remove quiet splash.

GRUB_CMDLINE_LINUX_DEFAULT="boot=zfs"

If your Ubuntu system will not boot make sure boot=zfs is in the linux stanza line in /boot/grub/grub.cfg

Update the Initramfs Boot Images


Update the boot images which will now contain the ZFS utilities, cryptsetup, cryptroot definitions and custom decrypt_derived shell script (if you chose single passphrase prompting).

update-initramfs -c -k all
update-grub
grub-install /dev/sda

Check the /boot/grub/grub.cfg and make sure your menu stanzas look something like this.

menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-/dev/mapper/root_crypt' {
recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  <UUID#>
        else
          search --no-floppy --fs-uuid --set=root <UUID#>
        fi
        linux   /vmlinuz-3.8.0-29-generic root=ZFS=/ROOT ro   boot=zfs quiet splash $vt_handoff
        initrd  /initrd.img-3.8.0-29-generic
}

Especially the linux line which MUST have root=ZFS=/ROOT and boot=zfs.

        linux   /vmlinuz-3.8.0-29-generic root=ZFS=/ROOT ro   boot=zfs quiet splash $vt_handoff

Exit the CHROOT ZFS Environment


Exit the chroot environment and unmount the system references. Unmount in reverse order in which they were mounted.

exit
umount /mnt/zfs/boot
umount /mnt/zfs/sys
umount /mnt/zfs/dev/pts
umount /mnt/zfs/proc
umount /mnt/zfs/dev

Export the ZFS pools (which will unmount /mnt/zfs).

zpool export vpool
zpool export rpool

Reboot

Remove the 8GB temporary Ubuntu installation storage and then reboot.

reboot

On reboot, you should be prompted for the passphrase to unlock the root_crypt LUKS container. If you set up with single prompting, the vault_crypt should be unlocked automatically for you with the derived master key. If set up with multiple prompting, you will be prompted again for the passphrase to unlock vault_crypt and each successive LUKS container defined in cryptroot.


Followup

Enable Timed Automatic Snapshots

  • Install and configure the zfs-auto-snapshot utility. It is the in the Ubuntu universe repository. On Git_Hub zfs-auto-snapshot. This provides Time_Machine like features for frequent, hourly, daily, weekly and monthly snapshots. zfs-auto-snapshot will skip datasets with the com.sun:auto-snapshot set to false. It does not currently support sending or receiving snapshots.

  • Enable scrub of your ZFS pools via cron. An example created in /etc/cron.d/zfs-scrub:

PATH="/usr/bin:/bin:/usr/sbin:/sbin"

0 10 * * 3 root zpool scrub rpool
0 12 * * 3 root zpool scrub vpool

Enable Health Monitoring

  • Install and configure a cron entry for the excellent zfs-health utility from calomel.org-zfs-health. Copy/create in /usr/local/bin/zfs_health.sh or wherever suited. This provides email notifications of missed scrubs, file system utilization > 80% and other health checks.

  • Setup zfs-health of the ZFS pools via cron. An example created in /etc/cron.d/zfs-health:

PATH="/usr/bin:/bin:/usr/sbin:/sbin"

0 14 * * 0-7 root /usr/local/bin/zfs_health.sh

Enable S.M.A.R.T Monitoring

Setup Snapshots to Send and Receive for Backups (untested: YMMV)

  • This is somewhat complicated, and should be scripted--here be dragons ;)

Setup a local backup on a removable drive

  1. Create a pool on your device, and in it, 1:1 filesystems to contain your backups (use your own hostname in lieu of zfsbox and rd-id-whatever..)
    1. zpool create -o mountpoint=none -o ashift=12 rdbackup /dev/disk/by-id/rd-id-whatever-you-have
    2. zfs create rdbackup/zfsbox/rpool/ROOT
  2. use existing automatic snapshots to populate the backup container filesystems (use your own snapshotname)
    1. zpool import rdbackup # ( if necessary )
  3. create an initial backup
    1. zfs send -R rpool/ROOT | zfs recv -F -d rdbackup/zfsbox/rpool/ROOT # For the first time
  4. update the backup set with cumulative intermediate snapshots
    1. last_snap=$(zfs list -H -t snapshot -ro name rdbackup/zfsbox/rpool/ROOT | tail -1 | cut -d@ -f2)
    2. zfs send -I -R rpool/ROOT@"${last_snap}" rpool/ROOT@snapshotname | zfs recv -F rdbackup/hostname/rpool/ROOT

Setup a network backup over ssh on a remote server with ZFS pool for backups

  1. set up public-key SSH authentication between zfsbox (your ZFS box) and deepfreeze (your remote backup host)
  2. create a filesystem on your deepfreeze (referring to your remote backup host): zfsbox (referring to your ZFS box) to contain your backups
    1. ssh zfs create -o mountpoint=none coldstorage/hostname/vpool # do this from your ZFS box "zfsbox"
  3. Perform an initial full backup
    1. zfs send -R vpool/VAULT | ssh deepfreeze zfs recv -F -d rdbackup/zfsbox/vpool/VAULT # For the first time
  4. subsequently, send cumulative incremental snapshots to deepfreeze
    1. last_snap=$(ssh deepfreeze zfs list -H -t snapshot -ro name rdbackup/zfsbox/vpool/VAULT | tail -1 | cut -d@ -f2)
    2. zfs send -I -R vpool/VAULT@"${last_snap}" vpool/VAULT@snapshotname | ssh deepfreeze zfs recv -F rdbackup/hostname/rpool/ROOT

Backup LUKS Headers (optional)

Follow the procedure at ArchLinux-LUKS-Backup. There are security implications. Read this section of the wiki with deliberation.

cryptsetup luksHeaderBackup /dev/sda2 --header-backup-file <pathToSave>/luks_sda2_header_backup
cryptsetup luksHeaderBackup /dev/sdb1 --header-backup-file <pathToSave>/luks_sdb1_header_backup
cryptsetup luksHeaderBackup /dev/sdc1 --header-backup-file <pathToSave>/luks_sdc1_header_backup
cryptsetup luksHeaderBackup /dev/sdd1 --header-backup-file <pathToSave>/luks_sdd1_header_backup
(repeat for each additional luks container) ...


Troubleshooting

  • If you boot into the recovery mode Ubuntu will likely not boot as boot=zfs is likely not on the linux menu stanza line. Manually add boot=zfs as an edit during grub. (Hold right-shift-key during boot to enter and edit the recovery menu).

  • If troubles, check for typos. I often transposed crypt as cyrpt because I was typing to haphazardly.

  • If you enabled splash screen for plymouth, but don't see it and have to blindly type the passphrase, you may need to enable FRAMEBUFFER=y and change the screen geometry. See this askubuntu thread GNOME-Broken-Splash. Boot without splash until you are certain the boot process is successful.

  • If on reboot you are dropped into the initramfs busybox menu, make sure the busybox has the ZFS utilities zpool and zfs, cryptsetup and the cryptroot files. The cryptroot should be in /conf.d/.... The custom key script in /scripts/luks. zpool status should return something.

  • The ZFS root pool MUST be named rpool.

  • boot=zfs MUST be on the linux grub.cfg menu stanza line.

  • root=ZFS=/ROOT MUST be on the linux grub.cfg menu stanza line. If you chose a different ZFS dataset name replace ROOT with your version.

  • Reboot back to the Ubuntu LiveCD, re-install the ubuntu-zfs packages, re-open the LUKS containers, re-import the ZFS pools to /mnt/zfs, chroot to the ZFS environment, adjust whatever you need to adjust, exit chroot, un-mount file systems, reboot. Rinse and repeat.

  • If the additional storage is not mounting automatically on booting, once boot is complete zpool import -d /dev/mapper vpool to mount the additional storage. This will 'refresh' the /etc/zfs/zpool.cache. df -mh to confirm the mounted pool. Then update-initramfs -c -k all to recreate the boot images which will have a reference to the most recent zpool.cache. Reboot and the additional storage pool should mount.


Distro Release Upgrade

Here is an upgrade scenario that takes some of the pain away from doing a distro upgrade. It avoids the chicken and the egg problem with the zfs third party module. I attempted to do an upgrade of the system by selectively re-enabling the zfs third party repo after the release upgrade had disabled all third party repo's. While the zfs was updated, when it came to re-building the dkms modules the kernel panicked and the upgrade failed miserably. (Having ZFS snapshots to rollback to was a god send)! Below is a way to do a relatively painless release upgrade.

  • Make sure ZFS repo supports the distro release you are upgrading to https://launchpad.net/~zfs-native/+archive/stable

  • Install the newer Ubuntu Desktop ##.## version you want to upgrade to on a bootable USB drive.
  • Boot from USB and 'Try Ubuntu' (If your system is using UEFI make sure to boot in that mode).
  • Open a terminal window; sudo -i

    apt-add-repository --yes ppa:zfs-native/stable
    apt-get update
    apt-get -y install ubuntu-zfs zfs-initramfs cryptsetup
  • Then open the encrypted target media, import the zpool's, mount, chroot and upgrade.
    cryptsetup luksOpen /dev/sda2 root_crypt
    cryptsetup luksOpen /dev/sdb1 vault1_crypt
    cryptsetup luksOpen /dev/sdc1 vault2_crypt
    cryptsetup luksOpen /dev/sdd1 vault3_crypt
    (repeat for each additional luks container) ...
    zpool import -f -d /dev/mapper -R /mnt/zfs rpool
    zpool import -f -d /dev/mapper -R /mnt/zfs vpool
  • If using UEFI make sure to add mount /dev/sda* /mnt/zfs/boot/efi after mounting /mnt/zfs/boot sda* being the boot_efi labeled device.

    mount /dev/sda1 /mnt/zfs/boot
    mount -o bind /proc /mnt/zfs/proc
    mount -o bind /dev /mnt/zfs/dev
    mount -o bind /dev/pts /mnt/zfs/dev/pts
    mount -o bind /sys /mnt/zfs/sys
    chroot /mnt/zfs /bin/bash --login
  • (Optional) To reduce the upgrade time, I removed all previous and unused kernel versions to avoid delete/rebuild dmks for each kernel.
  • During the do-release-upgrade when prompted to confirm the disable of third party repo's, before continuing, open another terminal tab and vi /etc/apt/sources.list.d/zfs-native-stable-raring.list and un-comment the deb. (Make sure the deb entry has the name of the release you are upgrading to).

    ln -s /dev/mapper/root_crypt /dev/root_crypt
    apt-get update
    apt-get dist-upgrade
    do-release-upgrade
  • If all goes well you can exit, unmount and export the pools. If all does not go well you can use zfs rollback to revert to a snapshot time before the upgrade and re-attempt with whatever things need to be tweaked.

  • Add umount /mnt/zfs/boot/efi if you are using UEFI boot.
    exit
    umount /mnt/zfs/boot
    umount /mnt/zfs/sys
    umount /mnt/zfs/dev/pts
    umount /mnt/zfs/proc
    umount /mnt/zfs/dev
    zpool export vpool
    zpool export rpool
  • Reboot, remove USB and enjoy your upgrade!

References

  1. http://www.larsko.org/ZfsUbuntu

  2. https://github.com/zfsonlinux/pkg-zfs/wiki/HOWTO-install-Ubuntu-to-a-Native-ZFS-Root-Filesystem

  3. http://docs.oracle.com/cd/E19253-01/819-5461/gaynr/index.html

  4. https://www.grc.com/haystack.htm

  5. http://pthree.org/2012/08/21/encrypted-zfs-filesystems-on-linux/

  6. https://wiki.archlinux.org/index.php/Disk_Encryption

  7. https://github.com/zfsonlinux/pkg-zfs/wiki/HOWTO-install-Ubuntu-to-a-Native-ZFS-Root-Filesystem

  8. https://wiki.archlinux.org/index.php/LUKS#Backup_the_cryptheader

  9. http://pthree.org/2012/12/05/zfs-administration-part-ii-raidz/

  10. https://wiki.archlinux.org/index.php/ZFS#Swap_volume

  11. http://askubuntu.com/questions/280779/gnome-broken-splash-screen

  12. https://github.com/zfsonlinux/zfs-auto-snapshot

  13. https://help.ubuntu.com/community/Smartmontools

  14. https://calomel.org/zfs_health_check_script.html

Creative Commons License

Author: James B. Crocker

EMail: james@constantsc.net

http://i.creativecommons.org/l/by-sa/3.0/88x31.png

This work is licensed under a Creative Commons Attribution-Share Alike 3.0 License.


CategorySecurity CategoryInstallation CategoryBootAndPartition CategoryEnterprise CategoryAdministration

encryptedZfs (last edited 2014-05-05 14:25:05 by ubuntu-james-crocker)