Ubuntu Server & L2ARC on Same Drives


New Member
Apr 27, 2021
I'm looking for some advice on partitioning a new system with multiple disks for root on ZFS with Ubuntu Server 20.04. This is the hardware I have:
  • 2 x Intel D3-S4610 256 GB SSD
  • 4 x Seagate EXOS 7E8 8TB
  • 32 GB ECC RAM (planning of expanding to 64 GB later)
In brief, this is what I tentatively think I want to do:
  • The two SSDs in a mirrored vdev for Ubuntu install.
  • Use most of the space on the SSDs for persistent L2ARC (in a striped configuration).
  • The four HDDs in a mirrored striped vdev configuration for storage.
I have read and plan on following the Ubuntu 20.04 Root on ZFS guide, but I have read up a lot on the topic lately I have limited experience with ZFS and Linux and do not understand all the aspects. I assume that following the install guide, I will get what I need in terms of partitions for rpool, bpool, EFI and swap. I see there are some warnings about the swap though, but I do not know whether or not I actually need it. How do I determine this and what is the alternative if not using it.

With regards to the L2ARC what would I need to do to configure this (what would be the actual commands)? Is that something I would do after completing the Ubuntu install guide? Do I need to change or modify any parts of the instructions in the guide to allow for the additional partition for the L2ARC?


Active Member
Jan 11, 2013
What use case are you trying to target here? Storing your movies? Multiple people accessing documents/roaming profiles? Virtual machine storage? A lot of usages have no benefit to L2ARC and will just wear your SSDs out.

Is this for a hobby/home use or is this for something important/production use?