Lessons learned from Ubuntu 20.04 [Focal Fossa] ZFS-on-Root.

Ubuntu20.04 ZFS on Root.md

Ubuntu 20.04 ZFS on Root

1. During installation you have to pick between Encryption or ZFS.
2. It is easy to add encryption to specific zfs file systems after installation.
3. ZFS on Linux's encryption call is different than Oracle's.

Everything in this thread relevant to encryption doesn't work.

From this thread: https://www.reddit.com/r/zfs/comments/bnvdco/zol_080_encryption_dont_encrypt_the_pool_root/

Oracle: zfs create -o encryption=on -o keysource=format,location e ....

Ubuntu/ZoL: zfs create -o encryption=aes-256-gcm -o keyformat=passphrase -o keylocation=prompt -o mountpoint=/tank/enc tank/enc

Mounting them at a later time:

zfs mount -l tank/enc

Pay attention to the -l.

Keywords: ZFS on linux encryption. ZFS encryption. Ubuntu 20.04 ZFS encryption

Adding a mirrored drive.

Problem: Ubuntu 20.04's installer doesn't allow you to create a mirrored zpool.
Solution: Add it later.

After installation go to a shell.

zpool status bpool

        NAME                              STATE     READ WRITE CKSUM
        bpool                             ONLINE       0     0     0
            wwn-0x50014ee2624f5972-part3  ONLINE       0     0     0

Copy the partition table to a new device & randomize guid. (See the symlinks in /dev/disk/by-id/)

sgdisk /dev/sdi -R /dev/sdj
sgdisk -G /dev/sdj

Attach the new drive. [I don't know if order is important, I put the existing drive first which is what all other examples show].

zpool attach bpool wwn-0x50014ee2624f5972-part3 wwn-0x5000c5006727f0f0-part3

Repeat for the rpool, copy the EFI partition, install grub. Reboot.