Apple (AFP) Shares

FreeNAS® uses the Netatalk AFP server to share data with Apple systems. Configuring AFP shares is a multi-step process that requires you to create or import users and groups, set volume/dataset permissions, create the AFP share(s), configure the AFP service, then enable the AFP service in Services → Control Services.

This section describes the configuration screen for creating the AFP share. It then provides configuration examples for creating a guest share, configuring Time Machine to backup to a dataset on the FreeNAS® system, and for connecting to the share from a Mac OS X client.

Creating AFP Shares

If you click Sharing → Apple (AFP) Shares → Add Apple (AFP) Share, you will see the screen shown in Figure 7.1a. Some settings are only available in Advanced Mode. To see these settings, either click the Advanced Mode button or configure the system to always display these settings by checking the box “Show advanced fields by default” in System → Settings → Advanced.

Figure 7.1a: Creating an AFP Share

Table 7.1a summarizes the available options when creating an AFP share. Refer to Chapter 3. Setting up Netatalk for a more detailed explanation of the available options.

Once you press the OK button when creating the AFP share, a pop-up menu will ask "Would you like to enable this service?" Click Yes and Services → Control Services will open and indicate whether or not the AFP service successfully started.

Table 7.1a: AFP Share Configuration Options

Setting	Value	Description
Name	string	volume name that will appear in the Mac computer's "connect to server" dialog; limited to 27 characters and can not contain a period
Share Comment	string	optional
Path	browse button	browse to the volume/dataset to share
Share password	string	maximum of 8 characters; this password is in addition to the user's password when authenticating
Share [Character Set]	string	only available in Advanced Mode; examples include UTF8 and ISO--8859-15
Allow List	string	comma delimited list of allowed users and/or groups where groupname begins with a @
Deny List	string	comma delimited list of denied users and/or groups where groupname begins with a @
Read-only Access	string	comma delimited list of users and/or groups who only have read access where groupname begins with a @
Read-write Access	string	comma delimited list of users and/or groups who have read and write access where groupname begins with a @
Disk Discovery	check box	enable if there is no DNS record for the FreeNAS® system
Disk discovery mode	drop-down menu	choices are Default or Time Machine (Apple's backup utility); due to a limitation in how Mac deals with low-diskspace issues when multiple Mac's share the same volume, selecting "Time Machine" on multiple shares is discouraged as it may result in intermittent failed backups
Database Path	string	specify the path to store the CNID databases used by AFP (default is the root of the volume); the path must be writable
Cache CNID	checkbox	only available in Advanced Mode; if checked, AFP uses the ID information stored in AppleDouble header files to reduce database load; do not set this option if the volume is modified by non-AFP clients (e.g. using NFS or CIFS)
Translate CR/LF	checkbox	if checked, AFP automatically converts Macintosh line breaks into Unix ones; may break some older programs
Windows File Names	checkbox	if checked, forces 8.3 filename restrictions imposed by older versions of Windows; it is not recommended for volumes mainly used by Macs as it breaks some some applications (e.g. OfficeX)
Enable .AppleDouble	checkbox	should only be unchecked when the network contains no Mac clients
Zero Device Numbers	checkbox	only available in Advanced Mode; enable when the disk device number is not constant across a reboot
Disable File ID	checkbox	only available in Advanced Mode; if enabled, AFP will not advertise createfileid, resolveid, and deleteid calls
Disable :hex Names	checkbox	only available in Advanced Mode; if this box is checked, AFP disables :hex translations for anything except dot files; this option makes the / character illegal
ProDOS	checkbox	only available in Advanced Mode; if checked, provides compatibility with Apple II clients
No Stat	checkbox	only available in Advanced Mode; if checked, AFP won't stat the volume path when enumerating the volumes list; useful for automounting or volumes created by a preexec script
AFP3 Unix Privs	checkbox	only available in Advanced Mode; enables Unix privileges supported by OSX 10.5 and higher; do not enable if the network contains Mac OS X 10.4 clients or lower as they do not support these
Default file permission	checkboxes	only works with Unix ACLs; new files created on the share are set with the selected permissions
Default directory permission	checkboxes	only works with Unix ACLs; new directories created on the share are set with the selected permissions

Connecting to AFP Shares as Guest

AFP supports guest logins, meaning that all of your Mac OS X users can access the AFP share without requiring their user accounts to first be created on or imported into the the FreeNAS® system. In this configuration example, the AFP share has been configured for guest access as follows:

1. A ZFS volume named /mnt/data has its permissions set to the built-in nobody user account and nobody group.

2. An AFP share has been created with the following attributes:

• Name: freenas (this is the name that will appear to Mac OS X clients)

• Path: /mnt/data

• Share Password: the password that will be used to access the share has been input and confirmed

• Allow List: set to nobody

• Read-write Access: set to nobody

• Disk Discovery: checkbox has been checked

3. Services → AFP has been configured as follows:

• Server Name: freenas

• Guest Access: checkbox is checked

• nobody is selected in the Guest account drop-down menu

Once the AFP service has been started in Services → Control Services, Mac OS X users can connect to the AFP share by clicking Go → Connect to Server. In the example shown in Figure 7.1b, the user has input afp:// followed by the IP address of the FreeNAS® system.

Figure 7.1b: Connect to Server Dialog

Click the Connect button and a login box, seen in Figure 7.1c, will appear. Since a password has been configured for this AFP share, the user must input the share password (i.e. not their own password).

Figure 7.1c: Authenticating to the AFP Share

Once connected, Finder will automatically open. The name of the AFP share will be displayed in the SHARED section in the left frame and the contents of the share will be displayed in the right frame. In the example shown in Figure 7.1d, /mnt/data has one folder named images. The user can now copy files to and from the share.

Figure 7.1d: Viewing the Contents of the Share From a Mac System

To disconnect from the volume, click the eject button in the Shared sidebar.

Using Time Machine

Mac OS X includes the Time Machine application which can be used to schedule automatic backups. In this configuration example, Time Machine will be configured to backup to an AFP share on a FreeNAS® system. To configure the AFP share on the FreeNAS® system:

1. A ZFS dataset named /mnt/data/backup_user1 with a quota of 60G was created in Storage → Volumes → Create ZFS Dataset.

2. A user account was created as follows:

• Username: user1

• Home Directory: /mnt/data/backup_user1

• the Full Name, E-mail, and Password fields were set where the Username and Password match the values for the user on the Mac OS X system

3. An AFP share with a Name of backup_user1 has been created with the following attributes:

• Path: /mnt/data/backup_user1

• Allow List: set to user1

• Read-write Access: set to user1

• Disk Discovery: checkbox has been checked

• Disk Discovery mode: set to Time Machine

4. Services → AFP has been configured as follows:

• Server Name: freenas

• Guest Access: checkbox is unchecked

5. The AFP service has been started in Services → Control Services.

To configure Time Machine on the Mac OS X client, go to System Preferences → Time Machine which will open the screen shown in Figure 7.1e. Click ON and a pop-up menu should show the FreeNAS® system as a backup option. In our example, it is listed as backup_user1 on "freenas". Highlight the entry representing the FreeNAS® system and click the "Use Backup Disk" button. A connection bar will open and will prompt for the user account's password--in this example, the password for the user1 account.

Figure 7.1e: Configuring Time Machine on Mac OS X Lion

Time Machine will create a full backup after waiting two minutes. It will then create a one hour incremental backup for the next 24 hours, and then one backup each day, each week and each month. Since the oldest backups are deleted when the ZFS dataset becomes full, make sure that the quota size you set on the dataset is sufficient to hold the backups. Note that a default installation of Mac OS X is ~21GB in size.

If you receive a "Time Machine could not complete the backup. The backup disk image could not be created (error 45)" error when backing up to the FreeNAS® system, you will need to create a sparsebundle image using these instructions.