Time Machine Backups to a Linux Server | Alt255 Blog

February 18, 2017

Time Machine Backups to a Linux Server

There are many writeups on how to backup a Mac using Time Machine to a Linux server. These are my notes.

First, create a user on the Linux system to which the Mac will login:

$ sudo useradd -m macbook
$ sudo passwd macbook

Next, install the necessary servers and libraries. Most sites I looked at showed downloading and source code for netatalk specifically to compile in encryption support (which may have be required by OSX). On Ubuntu 16.04 right now, the current version of netatalk is compatible with OSX; no download and compilation required.

$ sudo apt install netatalk libc6-dev avahi-daemon libnss-mdns

Update the nsswitch.conf:

$ sudo vim /etc/nsswitch.conf 

Make the hosts line to read as such:

hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4 mdns

Dump the following into afpd.service:

$ sudo vim /etc/avahi/services/afpd.service
<?xml version="1.0" standalone='no'?><!--*-nxml-*-->
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
    <name replace-wildcards="yes">%h</name>

Note that the firewall will need to accept connections on TCP port 458.

The main configuration for the file server appears to be in AppleVolumes.default. Configuration seems to have a generous number of knobs. For now, I’ll create two shares, one for Time Machine backups and another for miscellaneous file sharing.

$ sudo vim /etc/netatalk/AppleVolumes.default

/home/$u        "Home Directory"
/archive/TimeMachine/$u         "Time Machine"  options:tm

The $u is a parameter that resolves to the user that has logged into the file sharing service. Since I created the macbook user above, the macbook user will get two file shares customized to that user.

Restart the services:

$ sudo service avahi-daemon restart
$ sudo service netatalk restart

Changes to AppleVolumes.default require a restart (or possibly just a reload?) of netatalk, but not avahi-daemon.