ZFS How to install a ZFS based system using an existing system

balanga · 2026-04-01T16:58:03+0100

How would I go about installing a zfs based system on a different partition using an existing system?

Do I first add a freebsd-zfs partition?

I want to install it manually. I'm hoping I will be able to boot via Ventoy.

balanga · 2026-04-01T18:26:26+0100

I've created a ZFS partition and created a zpool on it, and now I've just found

Making sure you're not a bot!

so I'll see how far I get, although I often misinterpret instructions so I'll probably encounter difficulties.

elgrande · 2026-04-01T18:32:34+0100

I just used the installer and manually created a ZFS partition, worked for me.
Downside: I is only one zpool and boot environments do not work.

grandpa · 2026-04-01T18:41:35+0100

balanga said:
How would I go about installing a zfs based system on a different partition using an existing system?

Do I first add a freebsd-zfs partition?

I want to install it manually. I'm hoping I will be able to boot via Ventoy.

Don't know if this could help. It's how I dual boot 14 and 15 on an old laptop with UEFI and zfs.

/grandpa

balanga · 2026-04-01T21:52:58+0100

grandpa said:
Don't know if this could help. It's how I dual boot 14 and 15 on an old laptop with UEFI and zfs.

/grandpa

I'm hoping I can boot via Ventoy and have eight partitions on the system.

balanga · 2026-04-01T21:54:51+0100

elgrande said:
I just used the installer and manually created a ZFS partition, worked for me.
Downside: I is only one zpool and boot environments do not work.

I don't know if the installer will allow me to install on a partition as opposed to using up the whole disk.

elgrande · 2026-04-01T22:01:25+0100

balanga said:
I don't know if the installer will allow me to install on a partition as opposed to using up the whole disk.

Yes it does, you just have to go through manual partitioning.
Then at some point it warns that zfs won't be able to boot, but it works anyhow. Worked for me on different devices.

balanga · 2026-04-01T22:24:36+0100

elgrande said:
Yes it does, you just have to go through manual partitioning.
Then at some point it warns that zfs won't be able to boot, but it works anyhow. Worked for me on different devices.

I'll give it a try.

drsnx60 · 2026-04-01T23:07:00+0100

The point of using ZFS is redundancy. ZFS is designed to keep your data safe. the design philosophy is to use TWO physical storage devices and mirror them.
Then the ZFS SCRUB function that compares the data on the two physical drives to check for corruption on one of the drives can be used as planned and prevent
your files to suffer from bit-rot. If your ZFS filesystem only exist on a single storage device, this functionality is not usable.
Of course you can use the snapshots , compression , encryption a.s.o. features , but the data redundancy cant be achieved with a single disk.
Most Laptops i have encountered can be equipped with DUAL identical M.2 NVME sticks these days,
then the best strategy is to Install FreeBSD over both Storage devices as a Mirrored ZPOOL.