Steps I followed to increase pod limit To update your existing installation with an increased max-pods, add a kubelet config file into a k3s associated location such as `/etc/rancher/k3s/kubelet.config`:

apiVersion: <http://kubelet.config.k8s.io/v1beta1|kubelet.config.k8s.io/v1beta1>
kind: KubeletConfiguration
maxPods: 250

edit

/etc/systemd/system/k3s.service

to change the k3s server args:

ExecStart=/usr/local/bin/k3s \
    server \
        '--disable' \
        'servicelb' \
        '--disable' \
        'traefik' \
        '--kubelet-arg=config=/etc/rancher/k3s/kubelet.config'

reload systemctl to pick up the service change:

sudo systemctl daemon-reload

restart k3s:

sudo systemctl restart k3s

Don't do that. If you use a config file it will ignore ALL the other cli args

Thanks for reply. I have not used k3s before. I have initiated the master with this argument. So I believe /16 is enough IPs.

INSTALL_K3S_EXEC="--flannel-backend=none --disable-network-policy --cluster-cidr=192.168.0.0/16 server --disable traefik,servicelb"

Coming to the point of --kubelet-arg=max-pods how do I do that exactly on already running nodes? What if I want to change pod limit to another value few times? We are just experimenting with pod we can run. These are AMD EPYC metal nodes.

no, that’s not what you need to change. you need to change the node cidr mask. By default each node only gets a /24

Thanks. Let me check your new suggestions. Is there any need to reset iptables after I uninstall k3s (agent or server) using uninstall script? I used calico before and after I run uninstallation script, I could see lods of entries in Iptables.

if you’re using Calico you might need to change things a bit, it has its own IPAM if I remember correctly so the node cidr mask is not used.

Noted. This is working for me

On master 
curl -sfL <https://get.k3s.io> | INSTALL_K3S_EXEC="--flannel-backend=none --disable-network-policy --cluster-cidr=192.168.0.0/16 server --disable traefik,servicelb --kubelet-arg=max-pods=350" sh - 
  
on workers  
curl -sfL <https://get.k3s.io> | K3S_URL=<https://MASTER-IP:6443> K3S_TOKEN=<token> INSTALL_K3S_EXEC="--kubelet-arg=max-pods=350" sh -

BTW, if I have to re run installed w/o the script....how can I do that? Some thing like below?

k3s server/agent INSTALL_K3S_EXEC="--flannel-backend=none --disable-network-policy --cluster-cidr=192.168.0.0/16 server --disable traefik,servicelb --kubelet-arg=max-pods=350"

You still need to fix the cidr mask or you will get errors once you get to around 200 pods and the nodes run out of IPs.

Well.....Looks like If I run

k3s agent K3S_URL=<https://MASTER-IP:6443> K3S_TOKEN=<token> INSTALL_K3S_EXEC="--kubelet-arg=max-pods=350"

multiple times (with different value of kubelet-arg) on agent node, the k3s agent services just hangs in second attempt and nodes goes into unready state. I could only got script installation to rerun

I think you’re mixing up running the k3s command to run k3s, and running the installer command to install it

Plz ignore command posted in my last message (which I can not edit now). I used

k3s agent --kubelet-arg=max-pods=300 --token=<RKN> --server=<https://IP:6443>

with max pod values multiple times and that kind of hanged the k3s agent on node which caused node to become notready state