obnam is a backup program I have used used in the past to backup my gentoo system. Now that I am using nixos I would like to setup backups for a number of reasons:
-
I am on satalite internet so building the nix store, and downloading files from dropbox again could cost a lot of time.
-
there are still a lot of files that are not in the nixstore.
Setting up obnam on nixos starts with installing it. This is done by adding obnam to the systemPackages.
environment.systemPackages = with pkgs; [
obnam
];The next part is setting up the configuration. obnam search for a config in the following order.
/etc/obnam.conf /etc/obnam/*.conf ~/.obnam.conf ~/.config/obnam/*.conf
Nixos is able to create an etc file from it’s configuration with the environment.etc attribute. To create /etc/obnam.conf add this code to configuration.nix.
environment.etc."obnam.conf" = {
enable = true;
text = ''
[config]
repository = /data/obnam/all
client-name = n1
log = /data/obnam/all.log
root = /
one-file-system = yes
exclude = /data
'';
};At this point (once nixos-rebuild switch is run) obnam can be run manually as root. It would be nice if backups were run daily though. This can be setup with fcron.
services.fcron = {
enable = true;
allow = [ "john" ];
systab = ''
@ 1d obnam backup
'';
};The above code will install fcron and setup a job to run obnam once a day. Since systemd is used on nixos it would be better to use a timer instead of fcron. This can be done by removing services.fcron and adding a systemd service and timer for obnam.
systemd.services.obnam = {
description = "Perform system backup";
script = "${pkgs.obnam}/bin/obnam backup";
};
systemd.timers.obnam = {
description = "run obnam every day";
wantedBy = [ "timers.target" ];
timerConfig = {
OnCalendar = "daily";
Persistent = true;
};
};