Airport Time Capsule no longer a recommended disk for backups with Time Machine

The filesystem that macOS now requires for Time Machine backups is the modern APFS, which Time Capsule, owing to its age, does not support. Time Machine, since macOS Catalina, also uses a different storage structure in APFS that is incompatible with the HFS+ filesystems before it. Apple killed off all of its network hardware several years ago, and only Apple knows whether they will enter this highly competitive market again. Don't count on it.

You may want to continue backing up with Wi-Fi but the third-party NAS will need to support and be supported by Time Machine. That narrows the low-cost playing field and you can never know if that third-party hardware will remain compatible with Time Machine as newer releases of macOS arrive. I have a 16 TB drive in my Synology NAS in the basement and I still never perform network backups via Time Machine, even though that NAS does support Time Machine.

Instead, I have been using APFS formatted and USB-C connected external drives on my Macs for years without data loss or inability to restore when needed. I happen to use the palm-sized Crucial X8 or X9 SSD drives which are really convenient for MacBook Pro usage. Both of these drives have been retired by Crucial, though there are other brands available with a small footprint for this purpose.

Before I upgrade the operating system to another major version, I perform a last Time Machine backup, label that drive with the date/time and macOS version, then set it aside. I start with a new Time Machine drive for the new operating system.

annanc14 wrote:

I'm getting messages saying that my Airport Time Capsule is no longer a recommended disk for backups with Time Machine.

Time Machine backups have been really useful and I don't want to back up to an external USB disk for safety reasons. Are Apple going to replace Airport Time Capsules with some new option?

I'd like to back up using wifi and keep doing it with Time Machine. It was very convenient.

From what Apple says about Time Machine Backup

If you have a USB drive or other external storage device, you can use Time Machine to automatically back up your files, including apps, music, photos, email, and documents.

Much like , not the same as, the other contributor

Security issues ?

Encrypt your backup disk

To truly protect your non replaceable Data

Have a 3-2-1 Rescue Plan in place and always current

3 Backups using 2 methods and 1 off site incase of natural disaster or un-natural disaster.

Each of the above should be done to a Dedicated Single Purposed External Drive 

Below link is intended to augment what TM Backup does 

https://bombich.com

Backing up to Network Attached Storage (NAS)

The convenience of a wireless backup to a NAS device is appealing. Based on user feedback, however, we discourage people from relying on NAS devices for their primary backup for several reasons:

• Write performance to a NAS device is typically, at best, comparable to writing to a USB 2.0 HDD
• Performance of a NAS accessed via WiFi can be 10-100 times slower than the average locally-attached hard drive.
• Periodically validating the integrity of data on a NAS device may be impractical due to network performance.
• WiFi backups are only as reliable as the network connection and macOS's network filesystem client.
• Filesystem transactions on a network filesystem incur a lot more overhead than filesystem transactions on a locally-attached filesystem, leading to very long backup windows when your data set has lots of files (e.g. > 250K files).

For primary backups, we recommend that you procure a USB or Thunderbolt hard drive and create a backup on that locally-attached disk.