From 8704fa509d5b11953fc284e112d142e05c516e83 Mon Sep 17 00:00:00 2001 From: Alberto Colla <alberto.colla@garr.it> Date: Thu, 9 May 2024 15:37:39 +0000 Subject: [PATCH] Update FAQ.rst --- web/support/FAQ.rst | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/web/support/FAQ.rst b/web/support/FAQ.rst index cd49efe7..ea25c943 100644 --- a/web/support/FAQ.rst +++ b/web/support/FAQ.rst @@ -9,6 +9,39 @@ Operations .......... +MAC address Issues detaching/attaching network interfaces +---------------------------------------------------------- + +With recent Debian-based systems (e.g. Debian12, Ubuntu20+) detaching and re-attaching network interfaces to VMs can raise issues. + +The cause is that the MAC address of the NIC is hard-written in the netplan (/etc/netplan/netplan.yaml) file via cloud-init at instance creation. If the network interface is removed and reattached the system cannot assign the new MAC address, raising the following error on the console log:: + + ... stages.py[WARNING]: Failed to rename devices: [nic not present] Cannot rename mac=fa:16:3e:69:15:67 to ens3, not available. + +As a consequence, the VM is no longer reachable + +Here is the procedure to correctly detach a VM NIC from Network A and attach to Network B. + + - On the OpenStack dashboard, go to Network -> Networks + - Select the private network attached to the VM (Network A) and click on Ports + - Find the port attached to the VM (e.g. looking for the IP address) and copy the correspondent MAC address + - (alternatively: SSH log on the machine; cat file /etc/netplan/<netplan_name>.yaml and copy the MAC address) + - Important: Take note of the SECURITY GROUPS attached to the VM as they will get detached together with the NIC! + - Detach the interface from the VM: + - go to Compute -> Instances; from the drop-down menu of the VM select Detach interface; on the pop-up windows select the IP address of the VM, then click Detach interface + - Go to Network -> Networks, select the network to be attached to the VM (Network B), click on Ports + - Click on Create Port + - On the pop-up window optionally choose a name for the port and PASTE the original MAC address in the MAC Address box + - Go back to the Instance page + - from the drop-down menu of the VM select Attach interface + - From the menu "The way to specify an Interface" select "By Port" and in the Port menu select the port previously created + - From the drop-down menu of the VM select Edit security Groups + - Re-add the security group previously attached to the VM + - Reboot the VM + +Now the VM is correctly attached to the new network! + + non-default (FAST and CAPACITY) volume types (garr-ct1 and garr-pa1 regions) ---------------------------------------------------------- -- GitLab