How to: Configure FreeNAS 9.3 for Time Machine with disk quotas

FreeNAS Logo

FreeNAS is an amazing software stack and purpose built for hosting dedicated file storage shares, so it makes for an excellent platform to host a Time Machine compatible network share for use with OS X.

I wanted to build a server that would provide a reliable backup location with data redundancy for multiple Macs, with the ability to scale the storage space to meet future needs. Something which the current line of Apple TimeCapsules don’t offer, not to mention they are expensive for what they offer.

This setup will allow any Mac on the local network to backup to a central server using Ethernet/Wireless. I have gone the extra mile and included the ability of being able to remotely backup my MacBook Pro when away in London to my FreeNAS server at home using my OpenVPN server, but that’s for another post.

To clarify this was my first time using FreeNAS, I had no prior experience with the platform before writing this guide, so anyone should be able to recreate my setup with no prior knowledge of FreeNAS. My post is an updated version of an existing article I found, but is also a result of my own trial and errors. It takes time to figure out what works and what doesn’t.


For storage I picked up 4 x WD Red 3TB for NAS (Inc WD Express Warranty) for £91.99 each (£183.98 total). I picked the 3TB over the 4TB partly because of cost, but namely for reliability as numerous forums discuss high failure rates for the 4TB models.

I decided to utilise one of my G7 HP MicroServers as a dedicated FreeNAS server. The 2 WD Red drives were installed for storage, as well as a 32GB SanDisk Cruzer for the FreeNAS OS. I also maxed out the 16GB Kingston ECC RAM to help cope with the ZFS filesystems (the minimum recommended is 8GB).


FreeNAS 9.3 Homepage
You need to have a working install of FreeNAS before you can attempt this guide. I won’t detail over the OS installation as it’s fairly simple and has been documented numerous times over online, without forgetting to mention the amazing documentation that comes with FreeNAS Doc.
FreeNAS 9.3 is the current release at time of writing and is what this guide is based on, although future versions should also work fine.

Create ‘time-machine’ Group

The first step is to create a system group for the Time-Machine share in preparation for adding users.
Under the ‘Account’ menu item, expand the ‘Groups’ item, then select ‘Add Group’. Note that in my screenshots I already have a group called ‘Time-Machine’, your system won’t have until you complete this step.
Add Group in FreeNAS for TimeMachine

An ‘Add Group’ dialog box should pop up, prompting you to create the new group.
FreeNAS Group Settings
Set the config as follows:

  • Leave ‘Group ID’ to whatever it is by default
  • Set ‘Group Name’ to ‘time-machine’

Leave everything else as default and click OK. Our newly created ‘time-machine’ group should be visible under the ‘Groups’ section now.

Create and Configure Time-Machine ZFS Dataset

Now it’s time to create the ZFS dataset which will be used to store the Time Machine backups. You must have a ZFS volume already created for this step, if you haven’t got one then you should go read through the ZFS primer in the FreeNAS docs.

Under the ‘Storage’ tab select the ‘Volumes’ menu item, then select your ZFS volume (Volume1 in my case) and then select ‘Create Dataset’.
FreeNAS Create ZFS Dataset for TimeMachine

A ‘Create ZFS Dataset’ dialog box should pop up, prompting you to create the new ZFS dataset.
FreeNAS Create ZFS Dataset Dialog
Ensure the wizard is in ‘Advanced Mode’ and then set the config as follows:

  • Set ‘Dataset Name’ to ‘Time-Machine’
  • Set ‘Quota for this dataset’ to ‘1000 GiB’

In the section option we are specifying a quota for the dataset, effectively settings the size of available disk space for our Time Machine backups. Change the value if 1000 GiB is not suitable for your setup.
Leave everything else as default and click ‘Add Dataset’. Our newly created ‘Time-Machine’ dataset should be visible under the ‘Volumes’ section now.

Now we need to configure the permissions for our ‘Time-Machine’ dataset, so that our ‘time-machine’ group has read/write access.
Select the dataset (Time-Machine) and then select ‘Change Permissions’.
FreeNAS Change ZFS Permissions

A ‘Change Permissions’ dialog box should pop up, prompting you to edit the ZFS dataset.
FreeNAS Change ZFS Permissions Dialog
Set the config as follows:

  • Set ‘Owner (group)’ to ‘time-machine’
  • Set ‘Mode’ checkboxes to the same as mine in the screenshot

Click ‘By setting the group owner to the ‘time-machine’ group, we are granting any users of that group read/write/execute permissions.

Create Time-Machine Users

Now it’s time to create a separate user to represent each computer that will use the FreeNAS server for Time Machine backups.
Under the ‘Account’ menu item, expand the ‘Users’ item, then select ‘Add User’.
FreeNAS Create User Dialog
Set the config as follows, but change the relevant information related to your setup:

  • Leave ‘User ID’ to whatever it is by default
  • Set ‘Username’ to ‘dans-macbook-pro’
  • Ensure ‘Create a new primary group’ is deselected
  • Set ‘Primary Group’ to ‘time-machine’
  • Set ‘Full Name’ to ‘Dan’s MacBook Pro’
  • Set ‘Password’ to something strong (mix of; uppercase, lowercase, numbers, 16 chars long)

Leave everything else as default and click OK. Our newly created ‘dans-macbook-pro’ should be visible under the ‘Users’ section now.

Create Time-Machine AFP Share

The last step on the FreeNAS server is to create the AFP Share that will broadcast the storage on the local network.
Under the ‘Sharing’ tab select the ‘Apple (AFP)’ menu item, and then select ‘Add Apple (AFP) Share’.
FreeNAS Create AFP Share Dialog
Ensure the wizard is in ‘Advanced Mode’ and then set the config as follows:

  • Set ‘Name’ to ‘Time Machine’
  • Set ‘Path’ to your ZFS dataset path
  • Set ‘Allow List’ to ‘@time-machine’
  • Ensure the ‘Time Machine’ box is checked
  • Ensure the ‘Default file permission’ is set to the same as the screenshot
  • Ensure the ‘Default directory permission’ is set to the same as the screenshot

Add Time Machine Backup to OS X

Finally the last step is to configure Time Machine itself to backup to the newly created share.
In OS X, select ‘Time Machine’ from within ‘System Preferences’, and then click the ‘Select Disk’ button.
Add FreeNAS to Time Machine in OS X Dialog
All being well your FreeNAS AFP share should be listed. If you select to use the disk for Time Machine you will be prompted to enter the username and password for the FreeNAS user we created previously. That’s the last step, Time Machine should begin backing up shortly after adding the disk. I recommend that the first backup be completed over Ethernet instead of wireless as the initial backup can take considerable time.

I have used this setup for a couple of years now backing up 4/5 Mac’s with no real issues. Any problems I have ran into have most revolved around sudden shutdowns of the FreeNAS server midway through Time Machine backing up due to power cuts/loss. My Storage is setup using ZFS in striped mirrored mode, meaning I get the best of both for speed and disk redundancy.

Please let me know if you found this guide useful, or spot any mistakes above.

Install and configure OpenVPN on CentOS 6


This article will provide a quick guide to installing and hosting your own OpenVPN server on CentOS 6.


First order of business is to ensure you have the Extra Packages for Enterprise Linux (EPEL) repository installed. This a Fedora Project special interest group (SIG) that maintains additional packages for RedHat based Enterprise Linux distributions. It will enable the install of the OpenVPN package.

rpm -Uvh

OpenVPN installation and configuration

Install the OpenVPN package from the newly added EPEL repository. OpenVPN 2.3.7 is the current version available at the time of writing.

yum install openvpn

Some guides will recommend copying the sample OpenVPN configuration, but I prefer to create one from scratch as it creates a cleaner config file that is easy to read and understand. You can if you wish still copy over the sample and edit as necessary to continue following the guide. Skip the command below if you wish to create one from scratch.

cp /usr/share/doc/openvpn-*/sample/sample-config-files/server.conf /etc/openvpn/server.conf

Create/edit the newly copied server config

nano /etc/openvpn/server.conf

Insert the following to the config. You can omit the comments indicated by ‘#’ if you wish.

# Enable TLS and assume server role during TLS handshake.

# Use UDP as the main protocol
proto	udp

# Default OpenVPN port is 1194
port	1194

# Configure TAP interface, this allows for full-frame Ethernet packets to be sent. Useful for AFP required for remote OS X TimeMachine backups			
dev	tap

# IP Address allocation to clients for specified network/netmask. 
# The server will take the '.1' address ( 

# Absolute paths for server cert's and keys (created later on).
ca 		/etc/openvpn/ca.crt
cert		/etc/openvpn/server.crt
key		/etc/openvpn/server.key
dh		/etc/openvpn/dh2048.pem
tls-auth	/etc/openvpn/ta.key 0

# This is the network/subnet of your physical LAN the OpenVPN server will reside.
# Without this clients will be unable to ping other computers located on the same network as the server. 
push "route"
topology subnet

# DNS servers to be pushed to clients
push "dhcp-option DNS"
push "dhcp-option DNS"

# Drop privileges after initialisation to help improve security. 
user    nobody
group   nobody

# Used by the client to detect server timeout.
# Ping server every 10 seconds, assume timeout after 60. 
keepalive 10 60

# Enable compression
comp-lzo adaptive

# Run the process as a daemon

# Set logging verbosity, specify absolute paths for log files.  
verb 4
log-append	/var/log/openvpn.log
status		/var/log/openvpn.status

Certificate and Key generation

Now the OpenVPN configuration is complete, we need to generate some certificates and keys using a package Easy-RSA. Time to install more dependencies.

yum install easy-rsa

With the dependancy installed, it’s time to copy some required files into place.

mkdir -m 700 -p /etc/openvpn/easy-rsa/keys
cp -rp /usr/share/easy-rsa/2.0/* /etc/openvpn/easy-rsa

Now we edit the ‘vars’ file which contains all the necessary values for the Easy-RSA scripts to use.

nano /etc/openvpn/easy-rsa/vars

Change the key variables listed below contained in the ‘vars’ file to reflect your information.
You can omit the comments indicated by ‘#’ if you wish.

export KEY_SIZE=2048	# Can be increased to 4096 if desired
export CA_EXPIRE=3650	# 10 years CA expiration 
export KEY_EXPIRE=1095	# 3 year Certificates expiration
export KEY_PROVINCE="MyCounty"
export KEY_CITY="MyCity"
export KEY_ORG="MyOrg"
export KEY_EMAIL=""
export KEY_OU="MyOrgUnit"
export KEY_NAME="MyServer"
export KEY_CN="" # FQDN for server

We’ll now load the variables into the session and make sure the keys/ folder is empty using the clean-all script.

cd /etc/openvpn/easy-rsa
source ./vars

Time to build the CA private key and certificate with a password. Press enter when prompted and use a strong password.

./build-ca --pass

Now we build the server certificate. When prompted to enter the ca.key password, enter the password you used during CA creation in the previous step.

./build-key-server server

We generate our Diffie-Hellman key exchange file for the server. This can take a long time to generate depending on your computer.


The last step is to generate the tls-auth file

openvpn --genkey --secret keys/ta.key

It’s time to generate some client certificates.
This step can be repeated as many times as necessary to generate a unique certificate for each client. Replace ‘client’ with a unique name for each client.

./build-key-pass client

Now we copy all of the generated files into the OpenVPN conf directory.

cd /etc/openvpn/easy-rsa/keys
cp ca.crt server.crt server.key dh2048.pem ta.key /etc/openvpn

Routing config

Packet forwarding needs to be enabled on the server, so first we open the config.

nano /etc/sysctl.conf

Then edit ‘ip_forward’ to 1 if it’s not already set.

net.ipv4.ip_forward = 1

Create an iptables rule that will enable the server to forward packets to the rest of the network, received from VPN clients.

iptables -t nat -I POSTROUTING -s -o eth0 -j MASQUERADE

Save the firewall rules, enable the service to start automatically on boot and then restart the system.

service iptables save
chkconfig openvpn on

Client configuration

The server configuration part of this guide is over, now lets move onto the client configuration.

First we need to create the client config. Similar to the server config it’s easier to create a new client config from scratch.
Create a new file on your client called client.conf

nano client.conf

Insert the following client config below. Replace with the hostname/IP address of your OpenVPN server.

proto	udp
port	1194
dev	tap

ca		ca.crt
cert		client.crt
key		client.key
tls-auth	ta.key 1

ns-cert-type 	 server

comp-lzo adaptive

Next is to copy over the required certificates and keys from the server. Use some form of transfer; USB drive, SCP, SFTP and move the ca.crt, client.crt, client.key and ta.key to the same directory as the client config.

Mac OS X OpenVPN Client

Now we are ready to load the config into a OpenVPN client and test our setup.
For OS X, Tunnelblink is the best OpenVPN client to use.
Opening the client.conf with Tunnelblink should kickstart the config install, which will load the config, keys and certificates into a Tunnelblink profile. Once complete you should be able to successfully connect to your OpenVPN server.

To test connectivity you should be able to ping the OpenVPN server from the client, as well as Google’s DNS server to confirm external connectivity.


Mac Blinking Folder Icon – Hardware Fix

Flashing question mark startup error
You gotta love vague error messages

The other day my MacBook Pro (13-inch, Mid 2012) presented a flashing question mark during startup and was unable to boot to the OS. According to Apple docs this means that your Mac can’t find its system software. You gotta love pretty but vague error messages.

Resetting the NVRAM and holding down the safe mode/verbose boot keys did nothing to help, so I opened up the Mac to see if dust might be causing problems. After a blow out with some compressed air I tried booting again, with no success.
After digging out my external USB 3.0 caddy, I swapped in the SSD and to my surprise the system booted. This ruled out my initial suspicion that the SSD had died.
I let Disk Utility do its stuff checking the disk and OS, but didn’t report any issues apart from some minor permissions errors, nothing big enough to stop the OS booting though.

My focus turned to the MacBook’s internal HDD SATA connector, which is just a flimsy piece of thin metal with some embedded contacts. Luckily I had another MacBook Pro (13-inch, Late 2011) on hand and both HDD connectors looked very similar, so I swapped in the donor connector, popped the SSD back in and to my relief the Mac booted as normal.

Replacing the HDD connector

The local authorised Apple service centre wanted to charge over £100 + VAT for the replacement part and labour costs. Not wanting to get ripped off I ordered a replacement part off eBay for ~£25 inc postage. The SATA connector part number for my MacBook Pro (13-inch, Mid 2012) is: 821-1480-A, just search that on eBay.

Replacement A1278 HDD part
The replacement part I received

After reading online I can see people run into this problem for different reasons. In this particular case it happened to be a physical hardware fault, and not a software fault as most people seem to encounter.
After close examination I noticed the old cable connector was shiny on the underneath near the screw holes. My guess is that the back of the connector slowly rubbed against the chassis over time (caused by movement/vibrations) and was now creating a short of some kind, stopping the SSD from functioning normally.

Flush DNS OS X Yosemite 10.10.4 – discoveryutil command not found

With the recent update of OS X Yosemite to 10.10.4, the usual way of flushing the DNS using discoveryutil no longer works.

$ sudo discoveryutil mdnsflushcache; sudo discoveryutil udnsflushcaches
sudo: discoveryutil: command not found
sudo: discoveryutil: command not found

discoveryutil has been replaced by mDNSResponder in 10.10.4.
The following command should clear the DNS cache.

sudo killall -HUP mDNSResponder

Gigabyte GA-X58A-UD3R 48GB RAM working install

Corsair Vengeance 16GB RAM kit

A few days ago I spotted an awesome RAM deal on HotUKDeals, Amazon UK were selling 16GB of Corsair Vengeance low profile (2 x 8GB) DDR3 1866 Mhz for only £83.57 inc VAT + delivery. My order was placed at the right time so it seems, as according to Amazon price checker camelcamelcamel £83.57 is the lowest price recorded.

I already had a set of this RAM lying around, so ordered two more kits for a total of 48GB (6 x 8GB modules). 24GB is the official maximum supported RAM for the X58 chipset, but after reading online about some success stories with 48GB I thought it was worth a shot. Popped the modules in my Gigabyte GA-X58A-UD3R Rev 2.0 and can confirm it runs as sweet as a nut. OS X Yosemite recognises the full 48GB and all 6 modules correctly, with no issues reported so far.

A nice quick win, a rarity so it seams for Hackintosh builds 😛