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Restoring from a Time Machine back-up - puzzlement!

Hello - I've read here: https://support.apple.com/en-gb/HT203981


Yesterday, I decided to wipe the hard drive on my iMac and reinstall Catalina from my Time Machine back-up. When I had to choose WHICH back-up to install, I noticed something which I felt was rather odd. Instead of simply choosing a particular date/time of the back-up to use, I had a choice of which hard drive to select too! There were many more dates available on one of the disks than the other. I took a photograph of what I saw to show what I mean:-



Have you ever encountered such a thing before? HD and HD1 - as I’m sure you can see.


SHOULD it be like this? Is it a phenomenon of macOS Catalina perhaps?


I decided NOT to use my Time Machine back-up at all. I did erase my hard drive ……… and then did much ‘fiddling’ to get Catalina back up-and-running again on this machine. Everything seems to be working but I’m keeping my external hard drive in its original state for now - I’m NOT making any back-up for the time-being,


I’d really appreciate your thoughts on this. Thanks.


iMac 27" 5K, macOS 10.15

Posted on Oct 24, 2019 4:03 AM

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deggie's reply is correct.


Rather than concern yourself with the reason TM assigned unique names to the restore source, you really ought to start from the beginning. Describe the end result you are seeking.


The reason is important. You erased that Mac's startup disk, and now you want to restore a backup. Restoring a startup disk from a backup erases it first (TM tells you that) so erasing as a separate step wasn't necessary.


Furthermore, restoring the most recent backup recreates the exact same state that existed prior to erasing it. It gets complicated, because if you select "Macintosh HD" (or "HD 1") you are restoring its Local Snapshot. Time Machine tells you that too. That's a fine idea if your goal is to undo something you did subsequent to that backup's creation.


So, what you want to accomplish isn't clear to me.


Although a peculiarity of this site often results in similar or identical answers (often, existing replies don't appear until a new one is posted) unless I have something constructive to add I don't disturb a Discussion in which its OP is already receiving competent assistance. That's just me. I don't intend to impose that practice upon anyone, and in this particular case there's nothing to add to "you select the most recent backup," regardless of its name.


That's why I didn't reply. I'm replying now because you asked... but your question really needs more explanation: Why did you erase the startup disk?

Posted on Oct 27, 2019 12:08 PM

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Oct 29, 2019 5:07 PM in response to HunterBD

An external does not need anything installed to function. So, it is good practice to erase them and use DU to format them. That way you know what is on it. So I have been doing that for years - even with drives from OWC which I prefer since their external enclosures and the chip used for the connection are far better than WD's stuff.

33 replies

Oct 25, 2019 1:31 PM in response to mreed

I'm even more puzzled now! 🤨


You have no idea what dates were being shown when the other HD was selected - and I cannot remember! The dates, as far as I can recall were, though, different - and there were many more dates/times under one heading than the other.


Thanks, though, for trying to assist me with this matter. It's appreciated. 🙂

Question marked as Apple recommended

Oct 27, 2019 12:08 PM in response to HunterBD

deggie's reply is correct.


Rather than concern yourself with the reason TM assigned unique names to the restore source, you really ought to start from the beginning. Describe the end result you are seeking.


The reason is important. You erased that Mac's startup disk, and now you want to restore a backup. Restoring a startup disk from a backup erases it first (TM tells you that) so erasing as a separate step wasn't necessary.


Furthermore, restoring the most recent backup recreates the exact same state that existed prior to erasing it. It gets complicated, because if you select "Macintosh HD" (or "HD 1") you are restoring its Local Snapshot. Time Machine tells you that too. That's a fine idea if your goal is to undo something you did subsequent to that backup's creation.


So, what you want to accomplish isn't clear to me.


Although a peculiarity of this site often results in similar or identical answers (often, existing replies don't appear until a new one is posted) unless I have something constructive to add I don't disturb a Discussion in which its OP is already receiving competent assistance. That's just me. I don't intend to impose that practice upon anyone, and in this particular case there's nothing to add to "you select the most recent backup," regardless of its name.


That's why I didn't reply. I'm replying now because you asked... but your question really needs more explanation: Why did you erase the startup disk?

Oct 28, 2019 2:11 AM in response to John Galt

Hello John - thank you for responding. 🙂


There were LOTS of insignificant things happening on my iMac which weren't quite as expected so, for fun, I installed Kasperky's Internet Security software on a trial basis. By logging-on to my account on the Kaspersky website, I could see ALL my various devices running from/through my router! Not only that, but I was unable to use Kaspersky to run a scan on my machine. Both the Full scan and Quick scan failed. My paranoid perception was that *something* prevented that scan from happening! 


You'll no doubt think I'm crazy when I tell you that I've had an uneasy feeling - for a long time - that someone other than me was able to manipulate my machine! I just wanted to start over with a 'clean sheet' as it were!  😉


I was influenced, to a degree, by an article written by another retired naval officer. You may find same interesting yourself; you can find it here:- https://eclecticlight.co/2019/03/11/re-installing-macos-clean-or-what/


I subsequently discovered that my external hard drive - holding my Time Machine back-ups - appeared to be copying TWO hard drives, HD and HD1, as shown here:-



So, I erased my hard drive and have, hopefully, started completely afresh. 😁


Does YOUR Time Machine back-up have both HD and HD1?


Whilst I'm confident that you will already know, John, for anyone else reading here, the procedure to be followed is shown here:-


Restore your Mac from a backup - Apple Support


I hope this helps you understand. Your views will be most welcome!


D.

Oct 28, 2019 12:08 PM in response to HunterBD

I do understand, and no I don't think you're crazy. Having said that if you suspect malicious interference with your Mac or anything else, you're always better off inquiring here first (or somewhere else, provided you have confidence in the advice you may receive) before heading down some rabbit hole where you're only going to find more bizarre weirdness likely to feed into whatever paranoia may or may not be justified.


The very last thing anyone should ever do is to install some non-Apple "anti-virus" junk, unless of course it's merely for your own entertainment or to satisfy some morbid curiosity.


It's actually not accurate to say that's the very last thing anyone should ever do. Just don't do it, ever. For example I could describe my experience with "Kaspersky" specifically, but an accurate report would require the use of foul language so extreme no respectable website like ASC would permit it.


Does YOUR Time Machine back-up have both HD and HD1?


No, but I have a great number of TM backups and confess I just don't have the time to exhaustively inspect each one.


As I initially surmised, your question is a bit complicated and deserves more attention than I have been able to devote to it. In light of that limitation, here's what I recommend: First, be sure to obtain and use at least one additional, redundant, Time Machine backup device. You can use it in addition to your existing ones and TM will back up to it "in rotation". Satisfy yourself that TM is working properly with it, which might take a week or two of observing its operation. Then, when you are confident enough, take your existing "My Book", erase it using Disk Utility, and return it to Time Machine's rotation.


Unfortunately that will not address your question regarding the presence of "HD" and "HD 1" but there are too many complicating factors for me to provide anything more than a guess as to its appearance. The screenshot you posted is odd and doesn't resemble my TM backups, so all I can say is "that doesn't look right".


There are valid reasons to periodically erase a TM backup device. If nothing else the sheer number of files (well into the millions) just becomes overwhelming. When I realized some of my backups went all the way back to Lion, I erased them and started over. The length of time you want to keep backups is up to you, but in my case if I haven't required to restore something for several months, it's unlikely I ever will. So I erase it.

Restoring from a Time Machine back-up - puzzlement!

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