Storm season is back, bringing with it the potential for significant weather events. If you have clients in areas prone to infrastructure disruption, visit the Disaster Recovery Resources guide for preparedness information. Datto recommends performing proactive disaster recovery testing to mitigate potential downtime. See our articles about the importance of disaster recovery testing and Preparing For A Cloud Virtualization Test: Policies, Procedures, And Partner Responsibilities to learn more. For live updates, follow @datto on Twitter.

Backing Up Mac OS X to a NAS Share on a SIRIS or Datto NAS



This article will cover how to back up a Mac OS X machine onto a NAS share on a SIRIS or Datto NAS device.


  • An Apple system running OS X 10.5 Leopard or newer.
  • A Datto SIRIS or Datto NAS
  • Port 88 (AFP) must be open between the OS X machine and the Datto device.
  • User accounts on the Datto device that will be used to access the NAS shares from the target Mac(s) machine(s)

Create the NAS Share

Create the NAS Share on the device. For instructions to create the share on Datto NAS, skip to the Datto NAS section below.

SIRIS Devices

1. Log into the Remote Web for the SIRIS device

2. Select File Share followed by Network Attached Storage

3. Navigate to the Add A New Share

4. In the Create Share Wizard do the following (Figure 1). Once complete select Next:

    • Enter the sharename (ex: TimeMachine)
    • Allow configurations to the share as "Use Default Settings"
    • Under Share Type, select NAS Share

Figure 1 - Create A New Share Wizard

5. Once the new share has been created select Continue

6. It will go back to the Your Shares page. Select the Configure Share Settings under the new share created for this.

7. Ensure the share is private listed under the Make Share Public/Private

8. Navigate to Other Share Options and select Enable AFP/Time Machine in which will allow the Apple Filing Protocol (Figure 2)

Figure 2 - Enable AFP / Time Machine

9. Go to the Add User to Share and add at least one administrator to access and use this share. This will be used to access the share from the OS X System

Datto NAS Devices

1. Log into the Remote Web for the Datto NAS device.

2. Navigate to the Shares tab, and then click Add a New Share.

3. Set a name for the share, then select for the share type select NAS, as shown in Figure 3.

Figure 3 - Create Share

4. Click Next. You will see the screen as shown in Figure 4.

Figure 4 - Share Settings

5. In this screen, set the share to Private, select at least one user, and check off the box for Enable AFP. These credentials for the selected user(s) to access the share from the OS X system.

6. Click Next, and you will see the screen as shown in Figure 5.

Figure 5 - Snapshot Schedules

7. Set up the snapshot interval, offsite interval, and snapshot schedule. These settings effect the local and offsite replication processes.

8. Click Next, and you will see the screen as shown in Figure 6.

Figure 6 - Share retention schedules

9. Set up retention for the share. This will govern the local and offsite deletion of the snapshots taken of the share.

Configure the Share as a TimeMachine disk

Please perform the following steps on the target Mac machine.

1. First, connect to the Datto via Finder.

2. Open Finder, then hit Command + K to connect to a server

3. In the Server Address field, type in the following: afp://<IP of Datto device>/ 

4. Then, click Connect.

Figure 7
 - Connect to the Datto device from the Mac

5. Enter credentials for the local Datto device user we selected in the previous steps.

Figure 8
 - Enter the credentials for the NAS share

6. Open up System Preferences and navigate to the TimeMachine section.

Figure 9 - Time Machine control panel

7. Turn Time Machine on, then select the share name we created from the drop-down. Finally, click Use Disk.

Figure 10 - Choosing the Share

8. Time Machine backups will run as long as the Mac can communicate with the Datto across the local network.

Note: There are a few things to be aware with when using this type of share as a Time Machine disk. Due to the way Time Machine writes backups to a sparse bundle, the size of this file will grow indefinitely. This means that the storage taken up by the share will grow until there is no space on the Datto device. Once the device fills up, Time Machine will start deleting the oldest backups to create new ones. This is something to keep in mind if the device has other shares or agents on it. Additionally, this may also cause the size of your offsite backups to increase.

Troubleshooting AFP

If there are troubles connecting through AFP, please try the following steps:

1. Open the Terminal program on the Mac, and log in as the root user using this command:

sudo -i

2. Run the following command in Terminal:

defaults write TMShowUnsupportedNetworkVolumes 1

In the event that this does not work, please contact Datto Technical Support for further assistance in this process.

Time Machine Logs

Time Machine logs show up in the system.log file as The output looks like the following:

<agentName>.<DNS>.lan[4219]: Backing up to /dev/disk1s2: /Volumes/<volumeName>/<backupName>.backupdb

Was this article helpful?

2 out of 2 found this helpful

You must sign in before voting on this article.

Calling all Partners! We want to hear your feedback! Please participate in this quick survey and help us build a better, more-relevant Knowledge Base!

Want to talk about it? Head on over to our Community Forum!