Please explain TimeMachine backups to me

[SnowCrocodile]

Yes, I did read about it.

Still, would like to get some clarifications.

1. Am I right thinking that TimeMachine backups will not download data from iCloud that is not synced to the hard drive as "keep downloaded"?
2. Am I right thinking that there's no way to restore Notes without restoring the entire backup?
3. If 1 and 2 are correct, then what is the advantage of TimeMachine over conventional backups? It seems to be geared more towards backing up the system (apps and settings) than user data.

My habits from my 30 years of using PCs are to back up data (including cloud data) and not worry too much about backing up the system. Trying to see whether I should use an alternative solution to TM for that.

 

[MisterSavage]

3. If 1 and 2 are correct, then what is the advantage of TimeMachine over conventional backups? It seems to be geared more towards backing up the system (apps and settings) than user data.

Regarding #3, I had an update to MacOS go wrong and the Apple Store ended up wiping my Mac. My Time Machine backup restored my settings AND user data. It was as if nothing had happened.

 

[Sciuriware]

Yes, I did read about it.

Still, would like to get some clarifications.

1. Am I right thinking that TimeMachine backups will not download data from iCloud that is not synced to the hard drive as "keep downloaded"?
2. Am I right thinking that there's no way to restore Notes without restoring the entire backup?
3. If 1 and 2 are correct, then what is the advantage of TimeMachine over conventional backups? It seems to be geared more towards backing up the system (apps and settings) than user data.

My habits from my 30 years of using PCs are to back up data (including cloud data) and not worry too much about backing up the system. Trying to see whether I should use an alternative solution to TM for that.

Time Machine is the idea of constantly saving the modifications made to files.
In fact, that's what a software house needs.
I dropped TM because it remained copying all day and night and I found that the backup was not very manageable.
So I tried something else and ended at CCC (Carbon Copy Cloner) where the backup seems just another disk.
;JOOP!

 

[!!!]

1. Am I right thinking that TimeMachine backups will not download data from iCloud that is not synced to the hard drive as "keep downloaded"?

I keep all of my iCloud Drive files downloaded locally, and it backs them all up. TM isn't going to request all undownloaded cloud files every time it tries to back up, that would be really wasteful in terms of internet bandwidth. Please keep in mind that iCloud Drive is a sync service, and while it does have web-accessible recently deleted and file history features, it shouldn't be trusted as your only backup source.

2. Am I right thinking that there's no way to restore Notes without restoring the entire backup?

You can restore any individual file or folder whenever you want. I would personally advise against trying to restore and iCloud-synced notes database, though, as that may cause issues with syncing.(But I have done so, I restored an old notes database, copied out the text I needed, then reverted the notes database back to current (I did this with the internet disabled, and I had no issues further syncing).)

3. If 1 and 2 are correct, then what is the advantage of TimeMachine over conventional backups? It seems to be geared more towards backing up the system (apps and settings) than user data.

Time Machine used to keep an entire copy of the OS, so you could restore if you had a bad update. Nowadays it doesn't do that (unfortunately Apple seems to think that taking away control from the user is a good idea), but the general purpose is to be able to restore everything exactly as it was, including apps (this is useful for getting right back to work, instead of only having your user data and then having to redownload and install the apps you need). You can exclude the apps if you'd like.

Time Machine is really great for user data, since it keeps multiple revisions you can revert back to an older copy of a document. You can also do this with preferences or apps (if there was a bad app update).

 

[Bigwaff]

Time Machine used to keep an entire copy of the OS, so you could restore if you had a bad update. Nowadays it doesn't do that (unfortunately Apple seems to think that taking away control from the user is a good idea),

TM doesn’t back up macOS system files because the system is cryptographically sealed. Every install of macOS on every Mac is identical. Backing up macOS system files is unnecessary. Only user data is backed up by TM. Wiping and restoring an entire system from backup is no longer the process. One should use Settings > Erase All Contents and Settings to get a clean install of macOS. Then one can use TM with Migration Assistant to restore user data.

 

[!!!]

TM doesn’t back up macOS system files because the system is cryptographically sealed. Every install of macOS on every Mac is identical. Backing up macOS system files is unnecessary. Only user data is backed up by TM. Wiping and restoring an entire system from backup is no longer the process. One should use Settings > Erase All Contents and Settings to get a clean install of macOS. Then one can use TM with Migration Assistant to restore user data.

What if you want to restore to a previous update, though?

And I will continue wiping my entire system, no desire for this "trust apple" iOS-ification.

 

[Brian33]

What if you want to restore to a previous update, though?

It's pretty inconvenient, as far as I can tell. It's complicated by the read-only Signed System Volume (SSV) and the fact that macOS runs from a snapshot of that.

To my knowledge, the only way to "go back" to a previous specific version (From 15.5 back to 15.2, for example) is to either:

(1) create and boot from a "bootable installer" (typically on a thumb drive) (See here), or

(2) perform a DFU restore using Apple Configurator, an additional Mac, and the desired ".ipsw" file. Here's a maintained list of links to them (note that the links download from an official Apple server): https://mrmacintosh.com/apple-silicon-m1-full-macos-restore-ipsw-firmware-files-database/

See here for a Configurator restore to an older macOS: https://expandmacmini.com/apple-configurator-dfu-mode-installation-guide/ (I didn't find an official Apple page describing a restore to an older macOS version using Configurator -- only the procedure to restore to the latest macOS version using Finder.)

(3) ? It may be possible to use Carbon Copy Cloner (or Apple's 'asr' command directly?) to accomplish the downgrade. ??? Perhaps if you had a CCC "legacy bootable backup", you could boot from it, run CCC there, and create a "legacy bootable backup" of it on the Mac's internal drive. I wouldn't count on it working without testing the procedure, though. Recommended reading from a reliable source: https://bombich.com/en/kb/ccc/6/cloning-macos-system-volumes-apple-software-restore

I have not (recently, since Mojave) used any of these techniques and I may be off-base. I'd love to be corrected! It sure seems like downgrading to a known "good" version of macOS should be a lot easier.

 

[Brian33]

Backing up macOS system files is unnecessary. Only user data is backed up by TM.

I do agree with the main point of your post, but this statement could be misleading to some. There are many files outside the /User directory, that I consider "system files," that ARE backed up by Time Machine.

Specifically, the many important editable (with sudo) configuration files in /etc. Also, contents of /Library/LaunchAgents and /Library/LaunchDaemons. Probably most of /Library, I think, gets backed up. Also, wherever macOS keeps all its System Settings and associated databases, such as Privacy & Security (TCC) settings.

But again, I agree that the "normal" recovery procedure is to reinstall macOS, then use Migration Assistant from a backup volume.

 

[MayflyMaven]

What if you want to restore to a previous update, though?

It's unsurprising that Apple doesn't want to make it easy to downgrade the system; downgrading the system leaves it vulnerable to whatever security issues were fixed by the update (and those could be zero-day, actively-exploited issues). I don't disagree that it can be annoying if an update breaks something and then it's hard to downgrade, but from the platform security perspective, it's not great if downgrading is easy.

(3) ? It may be possible to use Carbon Copy Cloner (or Apple's 'asr' command directly?) to accomplish the downgrade. ??? Perhaps if you had a CCC "legacy bootable backup", you could boot from it, run CCC there, and create a "legacy bootable backup" of it on the Mac's internal drive.

I've tried that, it works. There was another way CCC was suggesting to do it to: Best practices for updating your Mac's OS, you just need to find the OS installer corresponding to the version of OS you're trying to downgrade to. Apple's website doesn't offer references to the old installers, but IIRC, you can find links to those (on Apple's servers – that part is key) at https://mrmacintosh.com

 

[maflynn]

. If 1 and 2 are correct, then what is the advantage of TimeMachine over conventional backups? It seems to be geared more towards backing up the system (apps and settings) than user data.

The advantage is, that it provides automatic data recovery and a measure of document versioning. When it was first introduced, Mac users were largely not backing up their computers. Apple provided a way to easily do that without any real intervention from the user.

Even today, where we have more robust backup solutions on the Mac And Windows, its one of the most elegant and simplest backup solutions.

Does it take too many snapshots, potentially through the night? Is it ideal in all circumstances, no, but for the general Mac user, its going to be their only option. For more technically adept people, and hobbyists like those who frequent MacRumors, there's other options.

Even so, I find TM to be a fire and forget option and I choose that over Super Duper or CCC. I've used both of those in the past but like traditional backups they tend to require a measure of manual intervention. I found myself missing backups due to my failures and laziness, with TM, I have no such issue.