OpenZFS 2.2.2 Linux kernel modules

[Arwen]

At some point between OpenZFS versions 2.1.4 and 2.2.2, they changed the amount of Linux kernel modules. In the past there used to be perhaps a dozen. Like separate ones for ZSTD and LUA. But yesterday when I updated my home Linux computers. (which use OpenZFS), the update to 2.2.2 mentioned removed obsolete modules. And when done, only these 2 remain;
extra/zfs.ko extra/spl.ko
In someways this is nice, reduces kernel clutter.

My normal practice for home Linux kernels is to build in any feature that I use, that has no issue with being built in. Meaning, unless their is a reason, like Bluetooth or certain crypto functions I don't use often, I have an all-in-one kernel. (And the converse is true, anything I never use, is not enabled in the kernel configuration... thus not part of my kernels.)

I wonder if this was due to a code cleanup. Have not been reading the OpenZFS GitHub Issues and Pull requests for more than a year... so perhaps it's time I start again.

 

[Arwen]

Updating another computer, I have this list of old kernel modules;

Code:

 * Found obsolete zfs module avl/zavl.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module icp/icp.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module lua/zlua.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module nvpair/znvpair.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module spl/spl.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module unicode/zunicode.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module zcommon/zcommon.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module zfs/zfs.ko for current kernel 5.10.74-gentoo.5, removing.
 * Found obsolete zfs module zstd/zzstd.ko for current kernel 5.10.74-gentoo.5, removing.

Two of them are still used as my original post, just updated;
extra/zfs. extra/spl.ko

Another weird thing, pool status shows some odd text of "(non-allocating)". See below. But, it appears to go away after reboot. This is probably due to the half upgrade, where user-land is updated but the modules are awaiting the reboot.
root@computer:~# zfs -V zfs-2.2.2-r1-gentoo zfs-kmod-2.1.14-r0-gentoo

Here is the odd pool status;

Code:

pool: rpool
 state: ONLINE
status: Some supported and requested features are not enabled on the pool.
        The pool can still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
        the pool may no longer be accessible by software that does not support
        the features. See zpool-features(7) for details.
  scan: scrub repaired 0B in 00:01:30 with 0 errors on Thu Feb 15 03:39:32 2024
config:

        NAME                              STATE     READ WRITE CKSUM
        rpool                             ONLINE       0     0     0
          mirror-0                        ONLINE       0     0     0
            nvme0n1p6                     ONLINE       0     0     0  (non-allocating)
            wwn-0x5002538e31716e4a-part6  ONLINE       0     0     0  (non-allocating)

 

[winnielinnie]

I noticed the same thing too on my Arch Linux system.

I actually agree with this new approach. Cleaner and more simplified.

It also makes checking/overriding parameters more straight forward.

 

[Arwen]

OpenZFS 2.2.2 does appear to change Grub2 compatibility. My root pools have "compatibility=grub2", which removed the suggested pool upgrade features message in zpool status. But, that message returned with OpenZFS 2.2.2.

Perhaps I need to see what Grub2 compatibility is today, with 2.2.2 and see if it is reasonable to enable missing features.

In my case, (all 4 Linux computers with root on ZFS), they still use an EXT4 "/boot" mirrored with MDADM. So in theory, I can have any ZFS features on my boot pool. (I sort of needed to maintain MDADM as swap on ZFS zVol is not perfectly supported on Linux.)

 

[probain]

OpenZFS 2.2.2 does appear to change Grub2 compatibility. My root pools have "compatibility=grub2", which removed the suggested pool upgrade features message in zpool status. But, that message returned with OpenZFS 2.2.2.

TrueNas has enabled this flag for me. And as such I do not see a suggested pool upgrade for 'boot-pool'.

Code:

boot-pool  compatibility                  grub2                          local

 

[Arwen]

Looks like these are the ones now supported by Grub2, that I don't currently have enabled;
allocation_classes userobj_accounting project_quota zpool_checkpoint spacemap_v2 log_spacemap resilver_defer livelist zilsaxattr device_rebuild block_cloning