Procedure to restore a Time Machine backup?

[UrsaMinor]

Situation:

Total hard drive failure on a Macbook Pro.

Questions:

1) If one was to explore a Time Machine Backup, would they be able to explore and copy the individual folders in the user account?

2) For Time Machine deployment, the new OS is installed to the new drive, then the TM backup is deployed. Correct?

3) If #2 is the correct procedure, then what problems may be encountered if the TM's apps are designed for an older OS than the newer one installed on the new drive?

Thanks

 

[Longkeg]

1. Yes, but not in any useful way. When you drill down into a Time Machine backup disk you’ll find a whole lot of folders all named with dates and a numeric code. They all seem to contain the same thing until you realize they are all snap shots in time. There could be 10s or even hundreds of versions of the same file from different times. It makes better sense to browse using the Time Machine app where you are given some context.

2. Time Machine will not install a new OS for you. It will restore whatever system was saved to the backup. I always take these tragedies as an opportunity to rebuild my system from scratch so I’ll download and install Apples latest OS release. Time Machine will recognize the newer OS and default to it. You’ll have to perform a system restore from Apple, either from a restore disk or over the internet. TM can restore the system back to the computer it came from but if you’re moving to a different machine you’ll have to get a usable (new) system on it before deploying TM.

3. Time Machine won’t let you restore files to a non-compatible OS. You’ll get an alert advising you to update the OS almost immediately. Once the backup is finished the Mac App Store will will prompt you to run updates for any older versions of installed apps.

 

[chscag]

A full Time Machine backup can actually be booted from and it will restore the version of macOS that it backed up. Not the fastest way to restore, but it does work. It's best to follow what @Longkeg wrote above.

 

[UrsaMinor]

Thank you for the replies Longkeg and chscag.

In researching what TM backs up, there seems to be a lot of conflicting and confusing information. For example some sites claim deploying a TM backup to a new drive will contain the OS and be bootable, yet some sites claim otherwise. Another example is some sites using the terms "operating system" and "system files" interchangeably, but others do not.

Anyway, I'm still kind of confused, so I'll be more specific and refine the "situation":

1) The Macbook was running El Capitan, and that's what the latest TM backup was created on. How would you proceed once the new SSD is installed if you want High Sierra on it? (assuming it will run HS).

2) Would the procedural steps differ if you didn't know what OS the TM backup was created on?

 

[Longkeg]

Actually the OS, or system files if you prefer, are the least important aspect of this. Why restore a backup of a system that’s been up and running for years? You’ll also be restoring any buggy or corrupt files that creeped in during all that time. It’s much better to wipe the hard drive, or put in a new one, and install a clean system from Apple. With a factory fresh system your MB is as close to new as you’re going to get. Now use Migration Assistant, in the a Utilities folder, to move all your files and apps from your TM backup to the destination machine. Not only is this a best practice but it will be faster than if you did a straight restore from TM.

As has been noted elsewhere in these forums, Time Machine isn’t really the best choice for whole disk backups. Time Machine can do it, it’s better than having no backup, but it will make you jump through a lot of hoops to accomplish your goal. Time Machine is at it best when your 5 year old accidentally deletes important documents and you don’t realize it until after the trash has been emptied.

 

[Weaselboy]

In researching what TM backs up, there seems to be a lot of conflicting and confusing information. For example some sites claim deploying a TM backup to a new drive will contain the OS and be bootable, yet some sites claim otherwise. Another example is some sites using the terms "operating system" and "system files" interchangeably, but others do not.

Since OS X Lion 10.7.2 the whole OS is backed up to TM and you can option key boot to a TM drive and format the new SSD then restore. That will put the entire OS and all your apps and data back on the drive.

Unless you already have a High Sierra bootable USB key to install from, I would just restore the El Capitan TM disk then afterwards update to High Sierra. You will get the same end result.

 

[UrsaMinor]

Thanks again for the replies. I understand now.

I was reluctant to restore the whole El Cap TM for the exact reasons that Longkeg posted, and had also considered the possibility of restoring the whole TM, then updating to HS.

I'll go with the new install of HS from my HS USB key, then try Migration Assistant. If that doesn't work (although I can't see why it wouldn't), I'll go with Weasleboy's method.

BTW-

I've been a Window's system computer tech for about 20 years, and have only started working on Apple computers about a year ago. Although I've become rather adept at repairing Apple systems (mainly no boot issues and SSD drive replacements in Macbook pros), this is the first time I've needed to utilize a TM backup. Since I've started working on Apple computers, I've come to love the operating system. I find it superior to Microsoft's operating system in many ways. One example of the superiority, is a no boot situation. Provided there is no hardware failure, it's simple to recover an Apple OS from a no boot. With the same issue on a Windows system, it's usually a nightmare. I can elaborate on the differences if requested.

 

[Weaselboy]

I'll go with the new install of HS from my HS USB key, then try Migration Assistant.

The thing is, if you have corrupt settings files and things like that, doing a full restore or a clean install then a migration will both bring those issues right back in anyway.

If there are corrupt files that are part of the OS (not user settings that MA brings in), then the OS update after the restore would fix/replace those files anyway.

If the Mac was working fine before you backed up, odds are a restore then upgrade will also work fine.

 

[UrsaMinor]

Weaselboy,

I was under the impression that the migration doesn't copy the OS. From looking at the Migrate info, the options for the migrate include "Appa, "The user account", "Other files and folders", and "Computer and network settings".

With that said, I see the appeal of your method, but I'm so used to Windows OS's in which installing a Windows OS upon an older OS is just asking for trouble. You end up with a hybrid OS that is typically fraught with problems. However unlike the Windows OS, it seems the same procedure with an Apple OS, results in basically a replacement (almost clean install) of the new OS...unlike a Windows hybrid.

 

[Weaselboy]

I was under the impression that the migration doesn't copy the OS. From looking at the Migrate info, the options for the migrate include "Appa, "The user account", "Other files and folders", and "Computer and network settings".

Migration does not copy the OS. But it does copy your personal settings and file. So for example if a plist file that contains your Mail settings is corrupt, that will get moved over with either MA or a restore either way.

macOS previously had an option that was more of an "upgrade" like you are describing how Windows was. There also was an option to essentially replace the OS. For years now those options are gone and the default upgrade essentially moves the old OS over, installs the new OS, then deletes the old one. It usually works quite well.

Where you often read about people running into trouble is if they have some app or utility that is not compatible with the newer OS version. But you will run into that issue using either method we have talked about here.

 

[UrsaMinor]

Yes, I have run into situations when a newly installed OS wouldn't open the old photos library, etc, but those issues were easily fixed.

Anyway, I'm clear and good to go now.

Thank you all