Update docs/vm/ for multiple NICs on a VM

Signed-off-by: Chris Chiu <[email protected]>

Author: mingshuoqiu

docs/vm/create-vm.md

@@ -42,6 +42,13 @@ Please refer to [this page](./create-windows-vm.md) for creating Windows virtual
 1. To configure networks, go to the **Networks** tab.
     1. The **Management Network** is added by default, you can remove it if the VLAN network is configured.
     1. You can also add additional networks to the VMs using VLAN networks. You may configure the VLAN networks on **Advanced > Networks** first.
+
+:::note
+
+If a VM is configured with multiple network interfaces, and at least one interface is connected to a VLAN network while another is connected to the Management Network, it may not be guaranteed that the Management Network IP is reachable from the nodes. This is because the VM's default route could have been overridden by the gateway of the VLAN network, causing the routing to prefer the VLAN network for inbound/outbound traffic, including traffic to the Management Network.
+
+:::
+
 1. (Optional) Set node affinity rules on the **Node Scheduling** tab.
 1. (Optional) Set workload affinity rules on the **VM Scheduling** tab.
 1. Advanced options such as run strategy, os type and cloud-init data are optional. You may configure these in the **Advanced Options** section when applicable.

docs/vm/edit-vm.md

@@ -41,6 +41,8 @@ You can add additional VLAN networks to your VM instances after booting, the `ma
 
 Additional NICs are not enabled by default unless you configure them manually in the guest OS, e.g. using [wicked for your OpenSUSE Server](https://doc.opensuse.org/documentation/leap/reference/html/book-reference/cha-network.html#sec-network-manconf) or [netplan for your Ubuntu Server](https://ubuntu.com/server/docs/network-configuration).
 
+When adding NICs, if one is connected to the Management Network, its IP may not be reachable from the node. This can happen if the VM's default route is overridden by the gateway of another network (e.g., a VLAN).
+
 ![edit-vm](/img/v1.2/vm/edit-vm-networks.png)
 
 For more details about the network implementation, please refer to the [Networking](../networking/harvester-network.md) page.
@@ -61,4 +63,4 @@ If you are using external storage, ensure that the storage provider supports vol
 
 Access Credentials allow you to inject basic auth or ssh keys dynamically at run time when your guest OS has QEMU guest agent installed.
 
-For more details please check the page here: [Dynamic SSH Key Injection via Qemu guest agent](./access-to-the-vm.md#dynamic-ssh-key-injection-via-qemu-guest-agent).
+For more details please check the page here: [Dynamic SSH Key Injection via Qemu guest agent](./access-to-the-vm.md#dynamic-ssh-key-injection-via-qemu-guest-agent).