SuperDuper’s “Follow-Up”
Recent versions of xOS (that is, macOS, iOS, iPadOS, etc) have Data Protection Classes from A to D that get assigned to files and folders.
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The thing is, though, is that these files and folders are inaccessible unless the user is logged in, and the screen is unlocked. A few seconds after the screen locks (or you log out), the keys are purged, and they cannot be read.
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That means the files any application considers to be worth protection cannot be accessed when a backup usually happens.
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You may have noticed that if you had an overnight backup, when you unlock your screen, a copy starts to run. It’s typically quite brief, thanks to ⚡️Turbo Smart Update, but it might surprise you anyway. […] During your overnight copy, SuperDuper kept track of the files that it couldn’t access due to their protection class. And now that it can access them, it’s making sure they get backed up.
This seems like the right thing to do. Time Machine also does it. A backup app should try to make as faithful a backup as possible. I kind of find it annoying, though. Sometimes it can’t do a Turbo Smart Update, and so the backup that should already be done may end up taking another 30 minutes or more. The best thing to do is schedule backups while you’re using your Mac to avoid SuperDuper needing to do such “follow-ups.”
I wrote some code to try to figure out which files I have that are using data protection. Interestingly, the URLFileProtection API seems to not work on macOS. I used the lower level getattrlist() instead. Nanian recommends fcntl(). I didn’t find any protected files that I actually care about, just caches and derived data from Apple’s own apps. But, in theory, Apple or a third-party app could be saving actual user data using data protection.
Previously:
- SuperDuper 4
- Launching Before UserDefaults Is Available
- Apple Addresses iOS Surveillance and Forensics Vulnerabilities
3 Comments RSS · Twitter · Mastodon
Well, no. That's not the "best thing to do"...in fact, I would suggest it's bad advice.
Time Machine is also going to take "a long time" if SuperDuper can't turbo.
For most people, SuperDuper 4 is typically run without the "UI" running. Any time it might take will have virtually no impact on the Mac's execution speed (no more than Time Machine), and would be running in the background just like Time Machine, with no real visual evidence, save for the menu extra, that it's happening.
The solution to running Time Machine is not to run it "when you're using your Mac"...it's simply to understand what's going on, and why.
In addition, for the vast majority of people, myself included, these follow-up runs are Turbo runs...and take a minute or two.
@Dave Really confused by your comment here. I’m not talking about when to run Time Machine; we generally don’t have much control over that. Since SuperDuper runs well in the background, I think it makes sense to run it when I’m at my Mac. That way the backup will be done when I expect, without really any side effects. If it runs overnight and then I log into the Mac and it starts doing a lengthy follow-up, but I want to eject the drives to pack up my laptop, that creates a problem. Often it can Turbo, but there’s no way for me to know ahead of time.
My point is that if it's not a problem that Time Machine is doing its catch-up runs (since they happen in the background anyway), it shouldn't be an issue with SuperDuper either, right?
*Most users* shouldn't be doing what you're suggesting here. I'm not saying *you* shouldn't, given your workflow.
I'm saying, as *general* advice, your suggestion is wrong. Users should not schedule it to run when they're at the Mac. They should generally schedule when they're not...and a quick follow-up when they wake the Mac isn't going to have a significant impact, and will likely be something they won't even notice.
