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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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babowa

Level 9

78,562 points

Posted on Oct 29, 2019 9:18 AM

The one thing I've gathered while seeing various posts on this type of problem is two folded:

Fact: Catalina splits the hard drive into Mac HD and Mac HD - Data. The first is the system and not writeable - you have no access to it. The second contains everything else and you have read/write permissions. The only place to see this is in Disk Utility and those two should be listed.
If there are two of either showing, it appears that it was a botched install and/or the drive was not erased before a "clean" install. Which would mean to use recovery and erase your drive completely and reinstall from Apple (rather than TM). You would have to use other means (setup assistant or drag 'n drop) to get your files moved over.

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HunterBD Author

Level 2

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Oct 28, 2019 3:32 PM in response to John Galt

As far as I can remember, I selected 'My Book' - the name I've always used for my WD external hard drive.

Does that help, John?

Have you looked yet to see what YOU see at that stage? I'd really like to know!

HunterBD Author

Level 2

307 points

Oct 29, 2019 10:28 AM in response to babowa

Thank you for your comments, 'babowa.

I have now obtained an enclosure for the 1TB hard drive I purchased last winter to install in my old iMac. I have called this new external hard drive 'My Back-up!'. Incidentally, that was the machine which I attempted to repair by heating the chip on the graphics card with a gas blow-torch - and failed! 😉

I replaced it with another (second-hand) iMac which has an SSD fitted and which now has a clean installation of OS X El Capitan. I have now 'tested' 'My Back-up!' on that computer. I carried out a Time Machine back-up without difficulty. I then shut down my machine and then restarted in Recovery Mode. Here's the proof!

I then moved forward to see if I had just one HD from which to recover - and I did! 😊

Satisfied that all was working well, I restarted my old iMac and ejected the external hard drive. I then connected 'My Back-up!' to my new iMac as had been suggested by John Galt. Here's proof again:-

I restarted my new machine in Recovery Mode and looked to see what was on offer - was it just HD ......... or HD and HD1?

You can see for yourself:-

Out of interest, because someone here on ASC said it would be no problem, I decided to proceed as if to restore from the back-up. This is the message I was shown:-

That was not unexpected by me!

Satisfied that all is now working properly, I restarted my iMac and am now writing this message upon it! 😎

My WD My Book 2TB external drive must hold the secret as to why I was earlier offered the choice of HD and HD1 disks from which to restore. I'm still hoping that someone can suggest who - or what - may have tampered with that drive.

Can anyone suggest a means of scanning the drive for malware? I don't really want to load any anti-virus software onto either of my iMacs! 🤔

Thanks for listening!

David.

babowa

Level 9

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Oct 29, 2019 11:32 AM in response to HunterBD

This is going to be my last comment here because it is delving into two things I do not use: TM (so I do not know how it works) and WD external drives, especially if they were not erased and formatted before use and therefore still have unnecessary WD software on them.

Your DU screenshot shows the two correct entries for your internal, so that is good. I have no idea what is happening on your external.

HunterBD Author

Level 2

307 points

Oct 29, 2019 4:39 PM in response to babowa

babowa wrote:

This is going to be my last comment here because it is delving into two things I do not use: TM (so I do not know how it works) and WD external drives, especially if they were not erased and formatted before use and therefore still have unnecessary WD software on them.

I wonder if you've hit upon a possible reason - the WD hard drive possibly having some of WD's software still installed. 🤔

I've been using the drive for some years and cannot remember whether or not I erased same. The 'My Book' product was, IIRC, supposed to be delivered ready for use by a Mac owner.

Your DU screenshot shows the two correct entries for your internal, so that is good. I have no idea what is happening on your external.

I'm now using a new external hard drive and don't appear to be having any problems at all.

Thanks for providing your views, 'babowa'. 🙂

HunterBD Author

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Oct 29, 2019 4:48 PM in response to ozpaul

Thanks 'ozpaul' - not quite the same snag - I effectively had FOUR drives being copied by Time Machine!!! 😳

You may be interested to learn that Catalina has had a major update today.

Detail here: https://eclecticlight.co/2019/10/29/catalina-10-15-1-is-now-available/

Maybe it's time for you to try again!

If so, Good Luck!

babowa

Level 9

78,562 points

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.

HunterBD Author

Level 2

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Oct 30, 2019 12:51 AM in response to babowa

babowa wrote:

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.

I completely understand that. Thank you.

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.

Is THIS the OCW to which you refer? https://www.owcdigital.com

I have no knowledge of, nor experience with, their products. I've always thought that Western Digital made good products but I'm simply a home user. Are you in some way better qualified to make the judgement that "the chip used for the connection are far better"? I was unaware that there is ANY "chip" involved! 😳

macjack

Level 10

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Oct 30, 2019 5:50 AM in response to HunterBD

Hi Hunter, the enclosure contains a chipset so the drive can communicate with the computer. A WD bare drive is fine but the quality of the chip they use in their enclosures is the issue she refers to. So if you were to purchase a WD bare drive and "roll your own" with an OWC enclosure, it should be fine.

The site you link to appears to be OWC but I've always used this link:

https://www.macsales.com

Maybe they just migrated to a new site.

Glad to see you got your TM issue sorted.

babowa

Level 9

78,562 points

Oct 30, 2019 8:36 AM in response to HunterBD

I am also "just a home user". There have been chipset failures documented. You can research it if you like. The site is macsales.com (known as OWC), located in the Chicago area. Since you are again delving into things, I will no longer reply to any of your posts.

HunterBD Author

Level 2

307 points

Oct 31, 2019 10:59 AM in response to macjack

Hi 'macjack' - I appreciate your comments and helpful advice. Thank you. 😊

I did, indeed "roll my own" using one of these - which I happened to have on a shelf nearby. It's designed for USB2 but seems to work just fine with Time Machine! https://www.ballicom.co.uk/dynamode-usb-hd3-5s-a-.p624997.html

That item was purchased some years ago from our local Currys/PC World emporium - I'd never heard of OWC before I came to the ASC! I'm confident that they don't have a retail store nearby.

Cheers!

HunterBD Author

Level 2

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Oct 24, 2019 7:39 AM in response to mreed

Thanks, 'mreed'!

The dilemma, then, is WHICH one does one select from which to reinstall - HD or HD1?!! 🥺

deggie

Level 10

167,519 points

Oct 24, 2019 5:45 PM in response to HunterBD

You select the most recent backup.

HunterBD Author

Level 2

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Oct 25, 2019 7:16 AM in response to deggie

There were TWO separate lists of available back-ups, 'degree'.

I apologise if I didn't make that clear - HD or HD1 could be selected; the lists were not the same!

WHICH list should I have chosen?

macjack

Level 10

111,242 points

Oct 25, 2019 7:58 AM in response to HunterBD

Responding to your query from another post:

https://discussions.apple.com/thread/250782308

I'm not running Catalina, so I'm not sure. But I suspect it would be HD and not HD 1

John Galt

Level 10

155,228 points

Oct 28, 2019 3:39 PM in response to HunterBD

I only recall seeing "Macintosh HD" but my Macs are scattered hither and yon and I'm not checking every single one. Does that one have two partitions (obvious question)?

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Restoring from a Time Machine back-up - puzzlement!