qm: add documentation for vm network MTU setting

Signed-off-by: Daniel Tschlatscher <d.tschlatscher@proxmox.com>

diff --git a/qm.adoc b/qm.adoc
index e7d0c07d9605172b1f98c3f42649db59398c41c2..428d388d81e059435e99257077d8788ee1f115cc 100644 (file)
--- a/qm.adoc
+++ b/qm.adoc
@@ -636,6 +636,11 @@ but not via the WebUI.
 You can also skip adding a network device when creating a VM by selecting *No
 network device*.
 
+You can overwrite the *MTU* setting for each VM network device. The option
+*mtu=1* represents a special case, in which the MTU value will be inherited
+from the underlying bridge.
+This option is only available for *VirtIO* network devices.
+
 .Multiqueue
 If you are using the VirtIO driver, you can optionally activate the
 *Multiqueue* option. This option allows the guest OS to process networking