Windows agent does start when data-dir in config.yaml contains a drive letter

[jwomack]

Environmental Info:
RKE2 Version:
rke2.exe version v1.33.6+rke2r1 (2c22982)
go version go1.24.9

Node(s) CPU architecture, OS, and Version:
amd64
Microsoft Windows [Version 10.0.20348.4405]

Cluster Configuration:
3 Masters
5 Linux Workers
1 Windows Worker

Describe the bug:
After settings the data-dir: "D:/var/lib/rancher/rke2" in the C:\etc\rancher\rke2\config.yaml, startup will fail.
From the debug output
level=fatal msg="Error: mkdir c:\D:: The filename, directory name, or volume label syntax is incorrect."

Steps To Reproduce:

• Installed RKE2: Followed the directions for Windows Air-Gap Install using image rke2-windows-ltsc2022-amd64-images.tar.gz and rke2.windows-amd64.tar.gz.
• Run: c:\usr\local\bin\rke2.exe agent --config /etc/rancher/rke2/config.yaml --debug

Expected behavior:
To be able to install on a drive other than C:\

Actual behavior:
Agent fails to start

Additional context / logs:
time="2025-12-03T00:01:13-08:00" level=info msg="Starting rke2 agent v1.33.6+rke2r1 (2c22982)"
time="2025-12-03T00:01:13-08:00" level=info msg="Updated load balancer rke2-agent-load-balancer default server: :9345"
time="2025-12-03T00:01:13-08:00" level=info msg="Running load balancer rke2-agent-load-balancer 127.0.0.1:6444 -> [] [default: :9345]"
time="2025-12-03T00:01:13-08:00" level=debug msg="Supervisor proxy using supervisor=https://127.0.0.1:6444 apiserver=https://127.0.0.1:6444 lb=true"
time="2025-12-03T00:01:13-08:00" level=warning msg="Cluster CA certificate is not trusted by the host CA bundle, but the token does not include a CA hash. Use the full token from the server's node-token file to enable Cluster CA validation."
time="2025-12-03T00:01:13-08:00" level=info msg="Updated load balancer rke2-api-server-agent-load-balancer default server: :6443"
time="2025-12-03T00:01:13-08:00" level=info msg="Running load balancer rke2-api-server-agent-load-balancer 127.0.0.1:6443 -> [] [default: :6443]"
time="2025-12-03T00:01:13-08:00" level=debug msg="Supervisor proxy apiserver port changed; apiserver=https://127.0.0.1:6443 lb=true"
time="2025-12-03T00:01:14-08:00" level=warning msg="Host resolv.conf includes loopback, multicast, or link-local nameservers - kubelet will use autogenerated resolv.conf with nameservers 8.8.8.8 2001:4860:4860::8888"
time="2025-12-03T00:01:14-08:00" level=info msg="Checking local image archives in D:\var\lib\rancher\rke2\agent\images for index.docker.io/rancher/rke2-runtime:v1.33.6-rke2r1-windows-amd64"
time="2025-12-03T00:01:14-08:00" level=info msg="Setting up calico CNI"
time="2025-12-03T00:01:14-08:00" level=debug msg="[GET]=>[/networks/] Request : "

time="2025-12-03T00:01:14-08:00" level=debug msg="[GET]=>[/networks/] Request : "

time="2025-12-03T00:01:17-08:00" level=debug msg="Found index.docker.io/rancher/rke2-runtime:v1.33.6-rke2r1-windows-amd64 in D:\var\lib\rancher\rke2\agent\images\rke2-windows-ltsc2022-amd64-images.tar.gz"
time="2025-12-03T00:01:29-08:00" level=info msg="Creating directory D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\charts"
time="2025-12-03T00:01:31-08:00" level=info msg="Creating directory D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin"
time="2025-12-03T00:01:31-08:00" level=info msg="Creating directory D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd"
time="2025-12-03T00:01:31-08:00" level=info msg="Creating directory D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\conf.d"
time="2025-12-03T00:01:31-08:00" level=info msg="Extracting file bin\confd\conf.d\blocks.toml to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\conf.d\blocks.toml"
time="2025-12-03T00:01:31-08:00" level=info msg="Extracting file bin\confd\conf.d\peerings.toml to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\conf.d\peerings.toml"
time="2025-12-03T00:01:31-08:00" level=info msg="Extracting file bin\confd\confd-service.ps1 to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\confd-service.ps1"
time="2025-12-03T00:01:31-08:00" level=info msg="Extracting file bin\confd\config-bgp.ps1 to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\config-bgp.ps1"
time="2025-12-03T00:01:31-08:00" level=info msg="Extracting file bin\confd\config-bgp.psm1 to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\config-bgp.psm1"
time="2025-12-03T00:01:31-08:00" level=info msg="Creating directory D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\templates"
time="2025-12-03T00:01:31-08:00" level=info msg="Extracting file bin\confd\templates\blocks.ps1.template to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\templates\blocks.ps1.template"
time="2025-12-03T00:01:31-08:00" level=info msg="Extracting file bin\confd\templates\peerings.ps1.template to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\confd\templates\peerings.ps1.template"
time="2025-12-03T00:01:32-08:00" level=info msg="Extracting file bin\calico-ipam.exe to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\calico-ipam.exe"
time="2025-12-03T00:01:33-08:00" level=info msg="Extracting file bin\calico-node.exe to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\calico-node.exe"
time="2025-12-03T00:01:34-08:00" level=info msg="Extracting file bin\calico.exe to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\calico.exe"
time="2025-12-03T00:01:35-08:00" level=info msg="Extracting file bin\containerd-shim-runhcs-v1.exe to D:\var\lib\rancher\rke2\data\v1.33.6-rke2r1-windows-amd64-13bd90b0a8d3\bin\containerd-shim-runhcs-v1.exe"
time="2025-12-03T00:01:35-08:00" level=debug msg="Calico Config: &{CNICommonConfig:{Name:Calico OverlayNetName:Calico OverlayEncap:vxlan Hostname:ConfigPath:c:\D:\var\lib\rancher\rke2\agent CNIConfDir:c:\D:\var\lib\rancher\rke2\agent\etc\cni CNIBinDir:c:\D:\var\lib\rancher\rke2\bin ClusterCIDR:10.42.0.0/16 ServiceCIDR:10.43.0.0/16 NodeIP: VxlanVNI:4096 VxlanPort:4789 Interface: IpamType:calico-ipam CNIVersion:0.3.1 KubeConfig:0xc000b8c080} KubeNetwork:Calico.* DNSServers:10.43.0.10 DNSSearch:svc.cluster.local DatastoreType:kubernetes NodeNameFile:c:\D:\var\lib\rancher\rke2\agent\calico_node_name Platform:bare-metal IPAutoDetectionMethod:first-found ETCDEndpoints: ETCDKeyFile: ETCDCertFile: ETCDCaCertFile:}"
time="2025-12-03T00:01:35-08:00" level=info msg="Shutdown request received"
time="2025-12-03T00:01:35-08:00" level=debug msg="Stopped health checking for load balancer rke2-agent-load-balancer"
time="2025-12-03T00:01:35-08:00" level=fatal msg="Error: mkdir c:\D:: The filename, directory name, or volume label syntax is incorrect."

[brandond]

There are probably going to be a LOT of things that are hardcoded to or otherwise assume C:, but we can work on addressing this.

I don't think Rancher supports putting things anywhere except the C: at the moment either.

[manuelbuil]

This feature is already in the roadmap. Covered internally by SURE-10749