Should I rely on iCloud do download everything after a Clean Install?

[eric.johnson]

I have never done a clean install since 2008. Every time a new OS came out, I would either migrate or do a TimeMachine restore. I am not sure if it is the mechanical hard drive slowing things down in 2019 (have a 2014 iMac, 24GB ram with the fusion drive), but I want to do a clean install. I have the 2TB iCloud plan, and everything is stored on there. All of my photos, all of my documents, I just ticked it all to be saved.

Am I right in thinking I have no worries just doing a clean install and letting the iCloud Drive download everything onto the computer again? My internet connection is fast, so I don't mind everything re-downloading.

If anything should go drastically wrong I have an up to date TimeMachine and a CrashPlan backup.

 

[chown33]

I wouldn't rely on anything until after I confirmed it worked. Test first, then commit.

The first test I'd do is putting a clean OS install on an external drive. Then pick one of your failsafes to restore from: iCloud, Time Machine, or CrashPlan. Then confirm that the restore worked. Since you still have your original internal HD, you can compare the original with the restored data.

The 2nd test I'd do is wiping that external drive, doing another clean OS install, then restoring from one of the remaining failsafes, and checking that it worked.

If they both worked, then you have 2 known-good ways you can recover. If only one worked, then make sure you leave the external disk with the working OS and recovered data on it. If neither of them worked, then you have a bigger risk to address before trying to do a reinstall and restore.

Finally, I'd wipe the internal HD, and do the clean OS install on it, then restore from the 3rd failsafe. Remember, when you're doing this, you still have the external drive with a known-good fully restored OS and user data on it, because you didn't erase it after you confirmed that the 2nd restore worked. You did, however, disconnect it from the Mac before you erased the internal HD, because you were thinking ahead and didn't want to accidentally do something to it while messing around with the internal HD.


My guess is that if you're running either High Sierra or Mojave on an internal mechanical HD, then the mechanical drive itself is contributing significantly to the slowdown. Since you didn't say what your OS was, I'm just going from my own experience running those OSes on spinning-platter drives.