enable CONFIG_RUST for Proxmox kernel

[uosiu]

Hello!

BcacheFS is going to utilize CONFIG_RUST in the kernel, can this option be enabled in upcoming kernels?

❯ dmesg -Tw | grep bcachefs
[...]
[Sat Feb 21 12:51:51 2026] bcachefs (20b15bfd-e996-4f45-8ab6-07b15bd9bae7): kernel does not have CONFIG_RUST enabled; this will be required for bcachefs in the near future - please alert your distribution or kernel developers if your kernel does not support CONFIG_RUST
[...]

 

[fiona]

Hi,
which kernel version are you using? Are you using the DKMS module for bcachefs?

 

[uosiu]

Kernel is 6.17.9 or something like that- latest from pve-no-subscription
bcachefs is DKMS from Kent's repository, updated daily.

Quote from Kent's Assistant (ProofOfConcept):

The CONFIG_RUST warning was added on Feb 17 (commit 3a63b3af6d0e). It's in bcachefs-tools, not the kernel itself — every bcachefs command prints it at startup if the running kernel lacks CONFIG_RUST.

As for timeline: the bcachefs-tools userspace is already mostly Rust. The kernel-side Rust conversion is planned but there's no fixed date yet — it's a large project. The warning is there to give distros advance notice so they can enable CONFIG_RUST in their kernel configs before it becomes required. If you're building your own kernel, enabling CONFIG_RUST now is a good idea.

 

[ness1602]

But for now bcachefs works great with 6.17 kernel

 

[jaminmc]

The Proxmox kernel is based on Ubuntu’s kernel. Since Ubuntu’s kernel version 6.19 includes CONFIG_RUST enabled by default, and unless the Proxmox team explicitly disables it in their next major release, CONFIG_RUST should remain enabled. As a result, future versions of bcachefs should work seamlessly on kernel 6.19 or whichever version Proxmox adopts next.

 

[deimosian]

The Proxmox kernel is based on Ubuntu’s kernel. Since Ubuntu’s kernel version 6.19 includes CONFIG_RUST enabled by default, and unless the Proxmox team explicitly disables it in their next major release, CONFIG_RUST should remain enabled. As a result, future versions of bcachefs should work seamlessly on kernel 6.19 or whichever version Proxmox adopts next.

Then the next thread will be asking how to disable it.