Mirror NVME boot drive?

Is it possible to mirror the boot drives without reinstalling the Operating System? Can ZFS be used for the file system?


@tmpearsall, No you would need to reinstall the OS to have a full mirror.

by default, the filesystem is not set up to be stripped. if we were to do this for enterprise we would have built the OS with an MDADM RAID first and then put the filesystem on top of that RAID,

now there may be a way to build a raid and move the filesystem but I’m not aware of any methods currently I cold be wrong

Thanks for replying. I’ve decided to install TrueNAS so will have the ability to reconfigure the boot drives.

After trying TrueNAS Scale, I decided to move back to Rocky/Houston. Took some trial and error to remove the boot partitions. Should install the MDADM RAID before installing Rocky? While I have managed to get Rocky installed, the process of installing Houston was not smooth. Specifically, the data drives were not recognized, came across the dalias work around which ultimately did the trick.

Currently, the HL15 is not supported as a standard chassis in our “dmap” tool which means you need to use the dalias tool to alias the drive slots.

we are working on adding direct support for the full build chassis in the dmap tool but for now, it will need to be manually done with dalias.

We do have these guides on our knowledgebase for installing Redundant Rocky and Houston

We are working on getting the HL15 master ISO image hosted on the website so that anyone wanting to start fresh can install it.


I’ve worked through those guides, custom configuration within Rocky as described doesn’t work for me. I get the feeling that the boot NVME drives are partitioned incorrectly. What partitioning scheme should be used and should a file system be applied?

Yes, you will need to make the MDADM raid on the 2 drives first and then put the XFS filesystem ontop of that.

You can put mostly all of the space in the / partition. you only need a small amount for swap “20G”

For the initial partition, before installing MDADM, how should I partition the drives? GPT w/xfs, something else?

Should MDADM be installed on unpartioned drives?

Hi All,

if you look a the guide I listed in my last post it has all the steps for installing Rocky on redundant boot drives.

The guide does not say which partitioning scheme should be in place before starting. The process, that is when I am asking for “custom”, fails and I think it might have something to do with the original partitions. I will try the process again and send screenshots later today. Please keep in mind that I had TrueNAS installed on this system which changed the boot drive partitions.

You should wipe the boot drive before the install process.

When installing a new OS there should be no partitions on the drive and it should be wiped clean.


Erased partitions on NVME0n1 and NVME1n1. Followed the Knowledge Base article for Mirrored Rocky installation. Selected both drives. Selected Custom Configuration. System errors were returned. Then attempted to follow the Troubleshooting instructions . As is, they failed. Created a mount point at /boot/efi (not biosboot) with a File System of EFI Boot System.

Installation completed successfully.

Thanks for all your assistance.


The /boot/efi/ partition would only be needed if your BIOS is using UEFI as the boot option.

If it is not you should not need this extra partition.

I haven’t changed bios settings since receiving the machine so it must have shipped, as a full build, with UEFI as the boot option. The mirror is recognized using the custom settings. Rocky is up, Houston is up and I am beginning to create ZPools.

Needed to clear the partitions on the non-boot drives, there seemed to be remnants of the TrueNAS config hanging around.

At this point, all appears to be good.