Reliable NAS for over-the-air Time Machine backup

According to Backup disks you can use with Time Machine - Apple Support, your NAS must support the Time Machine over SMB specification. Previous to that, NAS manufacturers would use an AFP hack (Netatalk) to share the TM backup since Apple never licensed AFP. Apple implemented features into AFP to enable reliable backups. Netatalk probably never did.

Apple now uses SMB for networking, so they created a specification for servers to use to make backups over SMB reliable. If the NAS merely claims to be able to share Time Machine destinations but doesn’t claim to support the Time Machine over SMB specification, they likely don’t.

If the NAS uses Samba for SMB file serving, it must be version 4.8 or later (released ca 2018) to have support for Time Machine.

I can’t say whether a NAS that supports TM over SMB would be necessarily reliable, but it certainly won’t be reliable if it doesn’t support the specification, and a NAS using AFP will always be unreliable.

Stay away from DLink. I will never trust them again after a bad experience with their routers many years ago. I'm also not a fan of WD since WD likes to lie & trick people.

You should check out Synology. I've never used them, but I have heard lots of good things about them (have been tempted to get one, but ended up building my own solution). A co-worker has one which he likes and I believe it supports TM backups. They have lots of options from small units to large.

FWIW, I have been using a Synology NAS for TM backups for over 2 years now. Pretty much ever since Apple decided to get out of the networking hardware game. Prior to this I was using a Time Capsule.

TM backups have been flawless, except one small "bump" with macOS Big Sur which was resolved by updating my NAS's operating system. It has been smooth sailing since. My NAS is a four-bay model with the option for a five-bay expansion. However, you can easily just use a two-bay unit if your goal is to only use it primarily for TM backups.

To give you a better idea on what it entails to setup, here's a Synology Knowledge Base article for you reading pleasure: How to back up files from Mac to Synology NAS with Time Machine - Synology KB

Carlos da Roza wrote:

My WD MyCloud apparently supports Time Machine over SMB. It does work, but not very reliably.

Does it actually say it supports the Time Machine over SMB specification, or does it just allow you to connect through SMB. They are not the same things.

Barney-15E wrote:

…Does it actually say it supports the Time Machine over SMB specification, or does it just allow you to connect through SMB.

WD My Cloud Home (there seem to be various models) does list Time Machine support:

https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/wd/product/external-storage/my_cloud/my_cloud_home/product-brief-my-cloud-home.pdf

https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/wd/product/nas/my_cloud/ex2_ultra/product-overview-my-cloud-expert-series-ex2-ultra.pdf

They only claim to work with Time Machine which is what they said when they used Netatalk for AFP connections. Those documents are not likely the place they would indicate support for the specification. You may have to contact them to find where they have that written.

Without support for that specification, it will necessarily be unreliable.

Barney-15E wrote:

They only claim to work with Time Machine which is what they said when they used Netatalk for AFP connections…

I’m running Synology, which works. I’m not looking to replace the Synology, either.

So… not chasing WD specs today.

And if WD is listing Time Machine support and using AFP for that, well, whoops.

Barney-15E wrote:

They only claim to work with Time Machine which is what they said when they used Netatalk for AFP connections…

I’m running Synology, which works. I’m not looking to replace the Synology, either.

If the Synology is running Samba 4.8 or later, it supports the specification. I had looked into them long ago and noted they were using Samba, but I haven't kept up with their current specs.

So… not chasing WD specs today.

I did some digging through their source code. WD does use Samba, and the WD firmware would need to be in the 5.xxx range to support the Time Machine over SMB specification (it uses Samba 4.9.5).

So, to answer the OP's question of a reliable NAS, any WD MyCloud would need to be running one of the 5.xx versions of their firmware to have any hope of being reliable with Time Machine.

I’ve been using and supporting Synology NAS boxes (with WD HGST HE-series HDDs) for Time Machine, and have had no issues.

FreeNAS / TrueNAS is another option, if there’s old x86 hardware around.