Problem with nfsd/nfs-client with kernel 6.17.4-2

[DirkH]

Hi,

I hit a roadblock updating one of our clusters to PVE9.1.4.
We have a 5 node cluster where one of the machines also has additional disks and shares them via nfs for backups and images. So on this node nfs-kernel-server is installed, the underlying fs is zfs. The mounts are facilitated via a separate network.

After upgrading the NFS-server node all hosts can mount the shares just fine, except the one where the nfsd is running.
It mounts the shares but for any subdirectory I get "stale file handle".

26-01-23T10:55:11.045452+01:00 proxffm06 pvestatd[2709]: mkdir /mnt/pve/nfs-images/images: Stale file handle at /usr/share/perl5/PVE/Storage/Plugin.pm line 1919.
2026-01-23T10:55:11.068183+01:00 proxffm06 pvestatd[2709]: mkdir /mnt/pve/backup-images/dump: Stale file handle at /usr/share/perl5/PVE/Storage/Plugin.pm line 1919.

The exports reads

/tank/backup-images     192.168.7.0/255.255.255.0(rw,async,secure,subtree_check,no_root_squash)
/tank/nfs-images        192.168.7.0/255.255.255.0(rw,async,secure,subtree_check,no_root_squash)

while the storage.cfg mounts are

nfs: backup-images
        export /tank/backup-images
        path /mnt/pve/backup-images
        server proxffmnfs
        content backup
        prune-backups keep-last=1
        options vers=3

nfs: nfs-images
        export /tank/nfs-images
        path /mnt/pve/nfs-images
        server proxffmnfs
        content images,iso
        prune-backups keep-last=1
        options vers=3

trying with nfs vers 4 didn't change the outcome.

As written the problem is solely present on the host that is the nfs-server itself all other cluster hosts PVE9 and PVE8 mount the shares without problems.

This behavior is observed under Kernel 6.17.4-2.
Booting into the old 6.8.12-16-pve fixes the problem.

I scanned some of the newer patch notes for 6.17.x but didn't get a clear hit.

Any suggestions?