How to Set Up Time Machine Backups to a NAS for Your Mac

A backup only protects you if it actually runs, and the surest way to make Mac backups run is to take the human out of the loop. Pointing Time Machine at a NAS does exactly that: macOS treats a network share as the backup destination and quietly saves versioned backups over Wi-Fi or Ethernet, with no drive to plug in and no step to remember. Set it up once and it backs up silently from then on.

Quick Answer

Create a shared folder on the NAS, enable SMB and the Time Machine broadcast option, make a dedicated user with a storage quota, then on the Mac open Time Machine in System Settings and select that share as the backup disk. macOS handles the versioned backups automatically from there. SMB is the protocol to use, since the older AFP is deprecated.

Why back up to a NAS at all

The appeal is automation. An external drive only protects you when you remember to plug it in, and the backups you skip are the ones you regret. A NAS sits on your network always on, so Time Machine connects and backs up on its own schedule without you doing anything. It also keeps your backups on your own hardware in your own home rather than a cloud subscription.

A NAS backup scales nicely too. One unit can hold versioned backups for several Macs in a household, each in its own allocated space, so the whole family is covered from a single box. That is far tidier than a drawer full of external drives.

Step-by-step: setting it up

1. Create a shared folder on the NAS

In the NAS control panel, go to the shared folder settings and create a new folder to hold the backups, giving it a clear name like TimeMachine. Leave the recycle bin and encryption options off for this share, since they add overhead Time Machine does not need. This folder is the destination your Mac will write to.

2. Enable SMB and Time Machine discovery

Make sure SMB file sharing is turned on in the NAS file services, because SMB is the current protocol Apple supports and AFP is deprecated. In the advanced file service settings, enable the service discovery option and, importantly, the setting that broadcasts the share as a Time Machine destination over SMB. That broadcast is what lets your Mac find the NAS automatically in the Time Machine settings.

3. Create a dedicated user with a quota

Make a separate NAS user account just for backups, and grant it read and write permission to the shared folder you created. Setting a storage quota for that user is worth doing, because Time Machine will otherwise keep filling space with older versions until the disk is full. A quota caps how much the backups can consume, leaving room for everything else on the NAS.

4. Select the NAS in Time Machine on the Mac

On the Mac, open System Settings, go to General, then Time Machine, and add a backup disk. If the NAS appears in the list automatically, thanks to the broadcast you enabled, select it. If it does not show up, connect manually to the share over SMB using the NAS address, then enter the credentials of the backup user you created. You will be offered the choice to encrypt the backup, which is worth turning on so your backed-up data is protected even if someone reaches the NAS.

5. Let the first backup run

The initial backup copies your whole system and takes a while, especially over Wi-Fi, so a wired Ethernet connection for that first run speeds things up considerably. After the first complete backup, Time Machine only saves what has changed, so subsequent backups are quick and unobtrusive. From then on it runs in the background with no further input from you.

A note on macOS compatibility

If you are on a very recent version of macOS and backups fail or disconnect partway, you may be hitting a known compatibility wrinkle between newer macOS releases and NAS SMB handling. It is a solvable configuration issue rather than a sign the approach does not work, so check that your NAS firmware is current and look up the specific fix for your macOS version if you run into it. Keeping the NAS software up to date heads off most of these problems before they start.

Choosing the right NAS for the job comes down to enough capacity for full versioned backups of every Mac you want to cover. You can browse the NAS units Evetech stocks to pick a chassis, and the storage drives local buyers choose most help you size the capacity to your backup needs.

Frequently Asked Questions

Do I need a special NAS for Time Machine?

No, most modern NAS units support Time Machine over SMB. You just need to enable SMB file sharing and the Time Machine broadcast option, then create a shared folder and a backup user. The main requirement is enough storage capacity for your versioned backups.

Should I use SMB or AFP for Time Machine?

Use SMB. The older AFP protocol is deprecated, and SMB is the protocol Apple currently supports for Time Machine to network storage. Enabling SMB and the Time Machine broadcast option on the NAS is the correct, future-proof setup.

Why should I set a quota on the backup user?

Without a quota, Time Machine keeps creating older versions until it fills the entire disk, leaving no room for anything else on the NAS. A quota caps how much space backups can use, so the rest of your NAS storage stays available for other purposes.

Can one NAS back up multiple Macs?

Yes. A single NAS can hold separate Time Machine backups for several Macs, each in its own allocated space with its own user account and quota. That makes it a tidy single backup destination for a whole household, replacing multiple external drives.

Will the first backup be slow?

The initial backup copies your entire system, so it takes a while, particularly over Wi-Fi. Connect the Mac to the network with an Ethernet cable for that first run to speed it up. After that, Time Machine only backs up changes, so later backups are fast and run quietly in the background.