Any Synology NAS can serve as a macOS Time Machine backup destination, replacing Apple's discontinued Time Capsule and providing a more flexible, storage-expandable backup target for Mac users. DSM natively supports the Time Machine protocol over SMB (and legacy AFP), so your Mac can back up automatically to the NAS over your local network just like it would to a Time Capsule. Hourly incremental snapshots, full system recovery capability, and no cloud involved.
In short: Create a dedicated shared folder on the NAS, enable it as a Time Machine target in DSM File Services settings, add a quota to cap how much space Time Machine uses, then select the NAS share in macOS System Preferences > Time Machine. Use SMB (not AFP) for modern macOS versions (Catalina and later). The process takes about 15 minutes. The most common problem is not setting a quota. Time Machine will consume all available space if you don't cap it.
SMB vs AFP: Which Protocol to Use
Apple deprecated AFP (Apple Filing Protocol) in macOS Big Sur and removed it as the default Time Machine protocol in macOS Monterey. DSM still supports AFP for older Macs, but use SMB for any Mac running macOS Catalina (10.15) or later. SMB is faster, more stable, and doesn't require enabling legacy protocols that Synology may deprecate.
AFP is still available in DSM via Control Panel > File Services > AFP. Enable it only if you're running a Mac on macOS Mojave or earlier. For everything 2021 and newer, ignore AFP and configure Time Machine via SMB.
Step 1. Create a Dedicated Shared Folder for Time Machine
Create a separate shared folder specifically for Time Machine. Using a dedicated folder makes it easy to monitor storage usage, set quotas, and manage permissions without affecting your other NAS data.
In DSM, open Control Panel > Shared Folder > Create. Name it something descriptive like TimeMachine or mac-backup. Select the volume with the most free space. Leave encryption off (encrypted volumes can't be used as Time Machine targets in some DSM versions). Click Next through the permissions step. You'll configure permissions shortly.
After creating the folder, go to Control Panel > Shared Folder > select TimeMachine > Edit > Permissions. Add the user account that your Mac will use to authenticate. The account needs Read/Write permission. If multiple Macs will back up to the same NAS, you can either use a single shared account or create separate DSM user accounts per Mac. Separate accounts make per-Mac quota management easier.
Step 2. Enable Time Machine Support on the Shared Folder
In Control Panel, go to File Services > SMB. Confirm SMB is enabled (it should be by default). Then go to the Advanced tab and scroll down to Time Machine. Enable the Time Machine toggle and select your TimeMachine shared folder from the list. Save.
This registers the share as a Time Machine-compatible destination that macOS can discover via mDNS (Bonjour). On your local network, it will appear in the macOS Time Machine disk selection list without any manual configuration on the Mac side.
Storage quota (critical): Before connecting the Mac, set a quota on the TimeMachine folder to prevent Time Machine from filling your entire volume. In Control Panel > Shared Folder > TimeMachine > Edit, there's a Quota tab. Set a size limit. A good rule of thumb is 2-3× the size of your Mac's internal storage. For a Mac with a 1TB SSD, allow 2TB on the NAS. Time Machine keeps hourly snapshots for 24 hours, daily for a month, and weekly until the disk is full. More space means longer backup history retained.
Step 3. Connect macOS to the NAS Time Machine Share
On the Mac, open System Settings (macOS Ventura+) or System Preferences (Monterey and earlier). Go to General > Time Machine (Ventura+) or directly to Time Machine (older macOS).
Click Add Backup Disk (or Select Disk on older versions). The NAS should appear in the list. It shows up as the Time Machine share you enabled. If it doesn't appear:
- Confirm the NAS and Mac are on the same network segment (same subnet)
- Try browsing manually: in Finder, Go > Connect to Server, enter
smb://[NAS-IP-address], and connect to the TimeMachine share - Check DSM File Services > SMB is enabled and the Time Machine option is set for the correct share
When you select the share, macOS prompts for credentials. Enter the DSM username and password you assigned Read/Write permission to the TimeMachine folder. macOS will store these credentials in the keychain for future automatic backups.
Click Use Disk. macOS creates a sparsebundle disk image in the TimeMachine folder and begins the first backup. The initial backup can take hours for a large system. Let it run overnight.
Step 4. Monitor and Manage Backups
Time Machine creates one .sparsebundle file per Mac in the TimeMachine shared folder. Open File Station on DSM to see these. The size of the sparsebundle reflects current backup usage. It grows as backup history accumulates and shrinks when old snapshots expire past the retention window.
To verify backups are running: on the Mac, click the Time Machine icon in the menu bar. It shows the last successful backup time and current status. If it shows 'Last backup: more than 24 hours ago', check that the NAS is powered on and the Mac is connected to the same network.
For multiple Macs, each creates its own sparsebundle in the same TimeMachine folder. They don't interfere with each other. Monitor the total folder size in Storage Manager to ensure you're staying within your volume capacity.
Recovering Files with Time Machine from NAS
File recovery works the same way as with a local Time Machine drive. On the Mac, open Time Machine from the menu bar, browse to a previous date, navigate to the folder or file you want to recover, and click Restore. macOS retrieves the file from the NAS sparsebundle over the network.
For a full system restore (e.g. after a hard drive failure or new Mac setup), boot into macOS Recovery mode (hold Cmd+R on Intel Mac, or hold the power button on Apple Silicon Mac until recovery options appear). Select Restore from Time Machine Backup, then choose the NAS as the source. You'll need to be on the same network as the NAS, and the NAS needs to be powered on and accessible. The restore streams data from the NAS over SMB. On a Gigabit LAN, a 500GB restore takes roughly 2-3 hours.
Wired Ethernet strongly recommended for both backup and restore. Wi-Fi works, but a Gigabit wired connection is substantially faster and more reliable for large data transfers. If your Mac only has USB-C/Thunderbolt ports, a USB-C to Gigabit Ethernet adapter ($20-40 from most AU electronics retailers) solves this.
Hardware and AU Pricing
Time Machine works on any Synology NAS, including ARM models that don't support Docker. The simplest option for a Mac-focused home network is the DS225+ ($585 at Mwave) with two 4TB WD Red Plus drives ($160 each). 4TB usable in RAID 1, roughly $900 total. That comfortably backs up 1-2 Macs with generous retention history.
If Time Machine is the primary use case and budget is a consideration, the DS223 ($489 at Mwave) is a more affordable entry point. It uses an ARM CPU so it won't support Docker containers, but Time Machine, file sharing, and Synology Photos all run fine on ARM models.
Compare this to Apple's discontinued AirPort Time Capsule (last sold ~$599 for 2TB in 2018. And no longer receiving security updates). Any current Synology NAS with larger drives provides better data protection (RAID), longer hardware support life, and more flexibility for expanding to other NAS functions in the future. All NAS hardware from AU retailers includes full Australian Consumer Law protections.
Related reading: our NAS buyer's guide, our Synology brand guide, and our 3-2-1 backup guide.
Use our free Backup Storage Calculator to size your backup storage correctly.
Does Time Machine work over Wi-Fi with a Synology NAS?
Yes, Time Machine over Wi-Fi works. But it's slower than wired Ethernet. The backup runs in the background, so speed matters most for the initial backup and for restores. On 5GHz Wi-Fi close to the router, speeds are typically 30-80MB/s, making a 500GB initial backup take 2-5 hours. On 2.4GHz or a weak signal, expect significantly longer. For day-to-day incremental backups (usually under 1GB), Wi-Fi is perfectly adequate. For full system restores, use wired Ethernet if possible.
Can multiple Macs back up to the same Synology NAS?
Yes. Each Mac creates its own sparsebundle file in the TimeMachine shared folder. Multiple Macs can back up concurrently. Though simultaneous large backups will slow down each other and the NAS. A practical setup is staggering backup schedules (or just letting macOS manage it. Time Machine naturally spreads out backup windows). For 3+ Macs, consider a 4-bay NAS like the DS425+ for more storage capacity.
Why does macOS say 'Backup Failed' or 'Disk Not Available'?
Common causes: (1) The NAS is asleep or powered off. Check DSM Power Management settings and disable HDD hibernation if you want instant backup availability. (2) The Mac and NAS are on different network segments (some routers with multiple VLANs isolate devices). (3) The SMB Time Machine option was changed in DSM. Check Control Panel > File Services > SMB > Advanced > Time Machine and confirm the correct share is selected. (4) The sparsebundle is corrupted. Rare, but fixable by deleting the sparsebundle on the NAS and letting Time Machine start a fresh backup.
Can I use the same NAS for both Time Machine (Mac backup) and Active Backup (PC backup)?
Yes. Time Machine uses the SMB share you configure, and Active Backup for Business handles Windows PC backup independently. They coexist on the same NAS without conflict. Use separate shared folders for each (e.g. TimeMachine for Mac, separate ABB destination for PCs) to keep storage usage visible and separately quotaed.
Does the NAS need to stay powered on 24/7 for Time Machine to work?
Time Machine only backs up when it can reach the NAS. If the NAS is in HDD hibernation or sleep mode, Time Machine will fail the backup attempt and retry later. For reliable hourly backups, set the NAS to wake on LAN activity or disable hibernation entirely (Storage Manager > HDD/SSD > HDD Hibernation > set to 'Never'). Alternatively, set Time Machine to daily backups. It's less likely to hit a hibernation window. For home use, leaving the NAS running is typically fine; a 2-bay NAS draws 10-20W, costing $3-6/month at Australian electricity rates.
Can I use a Synology NAS as a Time Machine target for an Apple Silicon Mac?
Yes. Apple Silicon Macs (M1, M2, M3, M4) use the same macOS Time Machine system and work identically with a Synology NAS SMB share. The restore process on Apple Silicon is slightly different (hold power button to enter recovery mode rather than Cmd+R) but the NAS-based restore works the same way. Confirm your DSM version is current (DSM 7.1+) for best compatibility with recent macOS versions.
Also backing up Windows PCs to the same NAS? Synology Active Backup for Business handles Windows PC and server backup at no extra licence cost. Pairs perfectly with Time Machine for a mixed Mac/Windows household.
Active Backup Setup Guide →