ct100

I found the reason this happens. Its not the eMMC itself, the boot from eMMC or booting from FAT vs EXT4. It's the much faster system boot speed from eMMC and the network configuration that leads to this bug.
 
The device that consumes the additional idle power is the Realtek RTL8125 2.5GbE NIC when left in an bugged unmanaged/unconfigured/off state.
 
When using stock Armbian with Network-Manager it seems to depend on the image, software distribution and the system boot speed with how often the Realtek NIC gets into this bugged state. Properly configuring the NIC in Network-Manager prevents this from happening.
 
 
When using Armbian Bullseye with OpenMediaVault installed with the OMVExtras InstallScript this can be reproduced 100%. The InstallScript (without using the option -n to skip network configuration) removes Network-Manager and lets systemd-networkd and OpenMediaVault/Netplan manage the network.
 
Since the MAC of the Realtek RTL8125 2.5GbE NIC is not fixed and changes every boot systemd-networkd with the policy "MACAddressPolicy=persistent" (default in /usr/lib/systemd/network/99-default.link) automatically adds a persistent MAC address to the Adapter. At the same time OpenMediaVault creates netplan files that assign network configuration based on this added MAC address.
 
This leads to a race condition in systemd-networkd. If systemd-networkd adds the persistent MAC to the adapter before it tries to assign the configuration matched to this persistent MAC everything works as expected. When the system boots faster systemd-networkd tries to match the configuration to a MAC that is not added yet to the adapter and that leaves the adapter off, unmanaged and bugged.
 
(In these code parts eth0 = GMAC & Realtek RTL8211F 1GbE and Realtek RTL8125 2.5GbE NIC = enP3p49s0)
 
Random MAC adresses:
Aug 28 09:53:57 nanopi-r6s kernel: r8125 0003:31:00.0 (unnamed net_device) (uninitialized): Invalid ether addr 00:00:00:00:00:00 Aug 28 09:53:57 nanopi-r6s kernel: r8125 0003:31:00.0 (unnamed net_device) (uninitialized): Random ether addr 4e:54:94:b5:ad:c7  
OMV Netplan file (matching with mac!):
root@nanopi-r6s:~# cat /etc/netplan/20-openmediavault-enP3p49s0.yaml network: ethernets: enP3p49s0: match: macaddress: de:d1:aa:55:c9:bf accept-ra: true dhcp4: yes dhcp4-overrides: use-dns: true use-domains: true dhcp6: yes dhcp6-overrides: use-dns: true use-domains: true  
Netplan auto generated systemd-networkd .network:
root@nanopi-r6s:~# cat /run/systemd/network/10-netplan-enP3p49s0.network [Match] MACAddress=de:d1:aa:55:c9:bf [Network] DHCP=yes LinkLocalAddressing=ipv6 IPv6AcceptRA=yes [DHCP] RouteMetric=100 UseMTU=true UseDomains=true  
When booting from slow microSD status of enP3p49s0 is ok:
root@nanopi-r6s:~# networkctl IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether routable configured 3 enP3p49s0 ether no-carrier configuring 3 links listed. root@nanopi-r6s:~# networkctl status enP3p49s0 ● 3: enP3p49s0 Link File: /usr/lib/systemd/network/99-default.link Network File: /run/systemd/network/10-netplan-enP3p49s0.network Type: ether State: no-carrier (configuring) Path: platform-fe180000.pcie-pci-0003:31:00.0 Driver: r8125 Vendor: Realtek Semiconductor Co., Ltd. Model: RTL8125 2.5GbE Controller HW Address: de:d1:aa:55:c9:bf HW Permanent Address: 4e:54:94:b5:ad:c7 MTU: 1500 (min: 68, max: 9194) QDisc: mq IPv6 Address Generation Mode: eui64 Queue Length (Tx/Rx): 4/4 Auto negotiation: yes Speed: n/a Port: tp DHCP6 Client DUID: DUID-EN/Vendor:0000ab1166a0671791d79f890000  
When booting from much faster eMMC enP3p49s0 is left in a bugged state:
root@nanopi-r6s:~# networkctl IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether routable configured 3 enP3p49s0 ether off unmanaged 3 links listed. root@nanopi-r6s:~# networkctl status enP3p49s0 ● 3: enP3p49s0 Link File: /usr/lib/systemd/network/99-default.link Network File: n/a Type: ether State: off (unmanaged) Path: platform-fe180000.pcie-pci-0003:31:00.0 Driver: r8125 Vendor: Realtek Semiconductor Co., Ltd. Model: RTL8125 2.5GbE Controller HW Address: de:d1:aa:55:c9:bf HW Permanent Address: 92:f6:18:f3:59:af MTU: 1500 (min: 68, max: 9194) QDisc: noop IPv6 Address Generation Mode: eui64 Queue Length (Tx/Rx): 4/4 Auto negotiation: yes Speed: n/a Port: tp  
The fix is to install OpenMediaVault without re configuring the network with InstallScript option -n. That keeps Network-Manger and doesn't add the ethernet adapters to the OMV database.
 
Another option is to remove Network-Manager and also remove the matching by MAC address from OMV netplan files by editing "/srv/salt/omv/deploy/systemd-networkd/netplan/files/ethernet.j2" and deleting:
match: macaddress: {{ mac_address }} After saving and applying the new network configuration in OMV webgui the MAC address matching is gone and adapters get only matched by name.