Since my previous tutorial on how to setup NFS with TimeMachine, you might wonder what prompted me to do this. The TimeMachine backups write to a virtual filesystem that is encapsulated in something called a sparsebundle. Unfortunately, if you have a problem with your sparsebundle, it simply isn’t possible to correct that issue over NFS. As a result, when my system started experiencing errors I found myself in a situation where it was going to be necessary to copy 1TB of backup data to another drive that would be local to my Mac.

This scenario simply isn’t practical, and since it would be necessary to get another hard drive and devote quite some time to copy the data from one host to another, I decided to explore AFP and configure Apple’s file sharing so that this problem could be resolved over the network directly.

These instructions assume your Linux server is running a recent version of Ubuntu.

1. Install Software. You’re going to need a few packages for this.
   apt-get install netatalk avahi-daemon libnss-mdns cracklib2-dev fakeroot libssl-dev
2. Configure Netatalk Service. This is what is going to host the file sharing services for you. Edit the /etc/default/netatalk settings to support the following configuration:

   ATALKD_RUN=no
   PAPD_RUN=no
   CNID_METAD_RUN=yes
   AFPD_RUN=yes
   TIMELORD_RUN=no
   A2BOOT_RUN=no

3. Setup Shares. Create the shares you want to access from your Mac. Edit your /etc/netatalk/AppleVolumes.default file and modify your share points from here. For this example, this was added to my AppleVolumes.default file to let me share the TimeMachine backup directory:
   /export/timemachine TimeMachine allow:eric cnidscheme:cdb options:usedots options:tm veto:lost+found
   Note that the veto option is handy as it will hide directories from your hosts that may be inaccessible.
4. Setup Name Broadcast. Modify your Avahi configuration to broadcast your host name information. This will make it easier to locate your Linux server from your Mac.
   To do this, create a file called /etc/avahi/services/afpd.service and place the following in it:

   <?xml version="1.0" standalone='no'?><!--*-nxml-*-->
   <!DOCTYPE service-group SYSTEM "avahi-service.dtd">
   <service-group>
   <name replace-wildcards="yes">%h</name>
   <service>
   <type>_afpovertcp._tcp</type>
   <port>548</port>
   </service>
   <service>
   <type>_device-info._tcp</type>
   <port>0</port>
   <txt-record>model=Xserve</txt-record>
   </service>
   </service-group>

5. Restart Sevices. With everything configured, restart your services.
   service netatalk restart
service avahi-daemon restart

That should do it. From your Mac, your Linux server should now be visible in the Finder. Use the Connect As… option to logon to your server using your credentials, and the available file shares should then appear.

If you plan on using this share for a TimeMachine backup, modify your TimeMachine settings and it to the new share. It’s also possible to run Disk Utility to repair your sparsebundle file on the server. In my case it took around 2 hours to complete, but it was successful and everything ran remotely.

The first thing you need to do is enable networked storage volumes for TimeMachine. This can be done at a command prompt with the following:

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1

The first thing you need to do is enable networked storage volumes for TimeMachineOnce networked devices are enabled, you will need a filesystem on your NFS share that your TimeMachine archive tool can write to. Rather than backup directly to a remote filesystem, a virtual filesystem is used that has been formatted to HFS+ specifications. To create this, enter the following:

hdiutil create -size 128g -type SPARSEBUNDLE -nospotlight -volname "Time Machine Backup" -fs "Case-sensitive Journaled HFS+" -verbose ./mybackup.sparsebundle

The sparsebundle must be created locally on your Mac for the first time, it will not write correctly to a remote filesystem over NFS. After the bundle is ready, from a command prompt open the mybackup.sparsebundle directory and create a file called com.apple.TimeMachine.MachineID.plist. The file should include the following:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist
  PUBLIC "-//Apple//DTD PLIST 1.0//EN"
  "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>com.apple.backupd.HostUUID</key>
<string>[YOUR_HOST_UUID_VALUE]</string>
</dict>
</plist>

To find your HostUUID, open System Profiler and on the Hardware Overview screen find the value labeled “Hardware UUID”. remember not to double click on the sparse bundle from the Finder, since this will mount the image and won’t let you create the plist file with your host UUID.

After getting this file into place, open the TimeMachine settings and point it to your NFS share. Before allowing the first backup to start, you may want to unmount the NFS share from your desktop. TimeMachine will take care of auto-mounting when it’s ready to run the backup, and when your computer is out of the office it will gently remind you that the backups have been trying to run without success.