mjhjmtu

I'm trying to symlink file /etc/systemd/network/00-default.link to /boot/00-default.link. This allows me to force a change to my MAC address from the boot directory, which is the only directory accessible from my Mac computer when I plug in the SD card.

However, when I use the command:

sudo ln -s /etc/systemd/network/00-default.link /boot/00-default.link

I receive the error:

ln: failed to create symbolic link '/boot/00-default.link': Operation not permitted

Any idea what might be causing this?

Note: I've created /etc/systemd/network/00-default.link already but I have not yet created /boot/00-default.link

/boot is a FAT filesystem that unfortunately does not support symbolic links.

So this cannot work

sudo ln -s /etc/systemd/network/00-default.link /boot/00-default.link

Turning it around and placing the file itself (source) on /boot and the link (target) on /etc however should do

sudo ln -s /boot/00-default.link /etc/systemd/network/00-default.link

This would however lack unixoid access permissions for the file - if that is an issue.

From your earlier questions, I know why you want to do this from boot, and symlinking /boot/00-default.link to /etc/systemd/network/00-default.link doesn't help, because /etc/systemd/network/00-default.link seems to be processed before /boot is mounted - therefore /etc/systemd/network/00-default.link is a broken link at the time it is being processed

I don't know if this is fact, but I know that linking that way also doesn't help, so I am assuming it to be fact :p

Here's a solution I came up with :p

Create a service in /etc/systemd/system - lets call it macoverride.service

[Unit]
Description=Copy user mac_override.link
ConditionPathExists=/boot/mac_override.link
After=local-fs.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/mv /boot/mac_override.link /etc/systemd/network/00-default.link
ExecStartPost=/sbin/reboot

[Install]
WantedBy=multi-user.target

Now, enable it

sudo systemctl enable /etc/systemd/system/macoverride.service

What this service does is

1. if /boot/mac_override.link exists - move it to /etc/systemd/network/00-default.link
   


2. reboot

Now, since step 1 moves the file, it won't exist after the reboot - so there's no chance of a reboot loop :p