If you own a Mac and a network-attached storage device, you can skip external hard drives entirely and back up wirelessly instead. This guide walks you through how to configure NAS for Time Machine backups, covering the NAS-side setup and the Mac-side connection, so your backups run automatically in the background without you thinking about it.

What you’ll need

  • A NAS device with enough free storage, ideally at least two to three times the size of the data on your Mac
  • Your NAS connected to the same local network as your Mac, via Ethernet for best results
  • Administrator access to the NAS management interface (via a web browser)
  • A Mac running a version of macOS with Time Machine built in
  • A dedicated user account on the NAS for backups, separate from your everyday login

Prepare the NAS for Time Machine

  1. Log in to your NAS’s web-based management console using its local IP address or assigned network name.
  2. Create a dedicated user account just for backups rather than reusing an admin login. If you haven’t done this before, it’s worth reading up on setting up dedicated NAS user accounts so permissions are locked down properly.
  3. Create a new shared folder specifically for Time Machine backups. Give it a clear name such as “TimeMachine” so it’s easy to identify later, and avoid storing other files in it.
  4. Set the backup folder’s permissions so only the dedicated backup account (and administrators) can read and write to it. This stops other network users from accidentally deleting or browsing the backup contents.
  5. Look in your NAS’s file services or network settings for a Time Machine option, sometimes listed under SMB or AFP settings. Enable Time Machine support for the shared folder you just created. Most modern NAS operating systems have a toggle specifically for this, since Apple’s Time Machine protocol needs the network share to advertise itself correctly.
  6. If your NAS offers a quota setting for the Time Machine share, set a reasonable limit. Without one, Time Machine can gradually consume all available NAS space over months of incremental backups.
  7. Check that network discovery protocols like Bonjour or mDNS are enabled on the NAS, since these let your Mac find the share automatically on the network.
  8. If your NAS uses RAID storage, it’s a good time to confirm your array is healthy before relying on it for backups. See this guide on configuring RAID for data protection for more detail on redundancy options.

Connect your Mac to the NAS

  1. On your Mac, open System Settings (or System Preferences on older macOS versions) and go to the Time Machine section.
  2. Click “Select Backup Disk” or “Add Backup Disk”, depending on your macOS version.
  3. Your NAS’s Time Machine share should appear in the list of available disks. If it doesn’t show up, use Finder to connect to the NAS manually first (Go > Connect to Server, then enter the NAS’s network address), which often helps it appear afterwards.
  4. Select the shared folder you created on the NAS and confirm.
  5. Enter the username and password for the dedicated backup account when prompted.
  6. Choose whether to encrypt the backup. Encryption is recommended for network backups, since the data travels over Wi-Fi or Ethernet and sits on a shared device.
  7. Let the first backup run. This initial backup copies your entire drive and can take several hours depending on how much data you have and whether you’re connected via Wi-Fi or a wired connection.

Tips and troubleshooting

Use a wired Ethernet connection for the first backup if at all possible. Wi-Fi works fine for the smaller incremental backups Time Machine performs afterwards, but the initial full backup moves a huge amount of data and a stable wired link avoids interrupted transfers.

If your Mac keeps failing to find the NAS share, double-check that both devices are on the same subnet and that any firewall on the NAS isn’t blocking the relevant network ports. Restarting the NAS’s file services after changing Time Machine settings often resolves connection issues too.

Keep an eye on available space. Time Machine automatically deletes the oldest backups once the destination fills up, but if the quota is too small, you may end up with only a few days of backup history, which defeats the purpose. If you also want your NAS available even when it’s been idle, setting up Wake-on-LAN means it can spin back up automatically the moment your Mac tries to connect.

A NAS rarely does just one job in a home network. The same box handling your Time Machine backups might also store security footage from a camera like the Reolink CX410, or feed a media player such as the Dune HD Homatics Box R 4K Plus over your network. If you want a quick local backup of critical files before they even reach the NAS, a compact portable drive like the Lexar Muse SSD is a handy stopgap while a scheduled Time Machine backup catches up in the background.

If you’re starting a NAS setup from nothing, it’s worth reviewing the basics of installing and configuring Synology NAS storage before diving into Time Machine specifically, since storage layout decisions made early on affect how much backup space you’ll have later.

Frequently asked questions

Can I use any NAS brand for Time Machine backups?

Most modern NAS platforms, including Synology, QNAP, and Asustor, support Time Machine through built-in SMB or AFP protocol options. The exact menu labels differ between brands, but the underlying process of creating a share and enabling Time Machine support is consistent.

Why can’t my Mac find the NAS in Time Machine settings?

This usually comes down to network discovery. Make sure Bonjour or mDNS is enabled on the NAS, both devices are on the same network segment, and the Time Machine option is actually switched on for the shared folder rather than just the SMB service in general.

How much NAS storage do I need for Time Machine?

Apple recommends allocating storage at least equal to, and ideally two to three times larger than, the data on your Mac’s internal drive. This gives Time Machine room to keep multiple historical versions of your files rather than just the most recent state.

Is it safe to back up over Wi-Fi instead of Ethernet?

Wi-Fi is fine for routine incremental backups once the first full backup is complete. For that initial backup, a wired connection is far more reliable and considerably faster, especially if you have a large amount of data to transfer.