Clean Install Sequoia on iMac 2019

TidBITS Talk
21

Yes, a good reminder. I’m talking about completely wiping out the computer as if I were going to sell it, then signing in as if I just bought it and using Time Machine, my CCC backup and/or a full backup to bring the system back to where I am without all the stupid glitches like a spacebar that doesn’t act like a Preview opening but drives everything crazy where spaces cannot be entered, tabs don’t work in WP programs, e-mails become impossible to respond to because everything typed in has no spaces or returns - a nightmare. I hope this will be fixed.

thank you for your reply - it is a good reminder!

22

Just wondering, how does a “backup program” differ from Time Machine and CCC?

23

a backup program backs up the whole computer, it is just another form of backup. I’ve found Time Machine iffy at times, though it has been better I understand. I m. big fan of CCC but CCC has been finding a bunch of errors from Dropbox of late and that makes me uncomfortable. I wonder if they are from the corruption causing all the issues with my computer. So I am just trying to be triple safe lol.

My biggest question is if anyone sees the any problem with wiping everything out and redoing my iMac as if I just bought it. If the issue then continues I still have it covered by AppleCare. Problem there is the the Apple Store is about 2 hours away and I am unable to travel that far. Woe is me ;-O

1 Like
24

A backup program keeps all versions of your data going back to the time of the first backup. This allows you to restore a file to some previous state. Time Machine doesn’t do this. It deletes previous versions based on a set of rules so it doesn’t run out of space. I believe CCC can be configured to either overwrite an older version or maintain a snapshot of previous versions. Programs like Retrospect use the snapshot method.

Any program that deletes or overwrites previous versions is not considered to be a true backup program.

1 Like
25

Not necessarily true. Most if not all backup programs typically expire backup data (either explicitly with retention periods or implicitly based on amount of free storage available for new backups). For things like tape and disk storage, that usually involves the deletion of old versions of data.

Snapshots still have to deal with the amount of disk space left. They’re more efficient because they don’t take up space for every piece of data - only data that has been added or changed). But eventually they can run out of space unless old snapshots are deleted (this goes for Time Machine as well).

Unless you want to deal with data migration when your backup media fills up, a more practical use of backup is to provide x weeks of operational recovery (e.g. your disk crashes, you deleted that file today and want to recover from yesterday’s version) - and size according.

Data archiving techniques and/or software tools should be used if you have data that you want to save “forever” - and that involves determining what data really needs to be saved forever because saving everything forever is costly. Using backup software to save everything forever is not a great idea - backup software is a really lousy data archiving tool for reasons too numerous to explain in a short post…

2 Likes
26

Thank you both for a very helpful post. It has helped me in fully understanding why I want to use a good backup program when I restore my hard drive. Do either of you have a good recommendation as to what program I could get to perform that task?

27

That’s a matter of opinion. All backup programs will either delete old content or fail when the destination device fills up. Which you prefer is a matter of preference and your specific requirements.

I currently use a 4TB hard drive to back up my Mac’s 2TB internal storage (of which about 1TB is used). My Time Machine backups go back to the first backup of this computer, because it hasn’t filled up yet. If/when it does fill up, however, I would prefer it to delete a backup from five years ago than to fail and not back up my current data.

If you have an Apple Silicon Mac, there is no way to restore a backup (bootable or otherwise) such that you can restore the system volume it to a new Mac’s internal storage (or to a wiped SSD) - you always need to boot the system’s macOS (possibly after reinstalling it first) and then restore the non-system content from your backup. Although the two most popular disk cloning tools (SuperDuper! and Carbon Copy Cloner) both provide a front-end to Apple’s ASR utility, it is not considered reliable, and is only known to work for making bootable external drives. I don’t think it is possible (someone correct me if I’m wrong) to boot from such a backup and then clone it to the Mac’s internal storage.

So if you need to perform a full wipe/restore of a modern Mac, you will be installing macOS via Apple’s Recovery system and then restoring your backup over that. This restore could take one of several forms:

  • Use Migration Assistant during the macOS installation, or soon afterward. This is what Apple recommends, and is the easiest solution.
  • Restore the entire content of a Data volume backup. This should work as long as Mac’s macOS release is the same as the one from the original system. If the macOS version doesn’t match (especially if it’s older than the backup), it is possible that something may break.
  • Manually copy your backed up documents and apps, but don’t touch the contents of the Library directories. This may require reinstallation of some apps and will almost certainly result in losing saved preferences.

All that having been said, in order to make that backup of your Data volume (or any volume other than the System volume), I would use one of the two popular cloning utilities: SuperDuper! or Carbon Copy Cloner.

If a more traditional backup (e.g. to a database-like file) is OK or preferable to a clone, Retrospect is still available. But it’s expensive. It is really more of an Enterprise backup solution and may be overkill for a personal backup solution.

I haven’t used Retrospect for a long time, but the last time I did, it would create a large opaque database file on the destination volume containing all the backed-up content, and an index file stored on your boot volume. Subsequent incremental backups append new data to the database and update the index. The result is not bootable and isn’t directly accessible - you need to use the Retrospect app to view or restore anything from those backup databases. The way you restore a system is to reinstall macOS, install Retrospect, and then run it to restore the backed-up content (it will regenerate the index from the database if it’s no longer available).

IMO, tools like Retrospect are best for making backups to remote network file servers or to high capacity devices like tape drives (which, these days, are far too expensive for non-enterprise users).

1 Like
28

A more affordable solution that some of the users here have used for many years is Arq 7. It can back up to many destinations, among them external drives. As @Shamino writes, it will not back up your macOS but will keep versions of your files if you configure it to do so.

1 Like
29

Sorry. Been out recovering from major surgery which is not a lot of fun compared with squaring my computer around lol. I like the Arq7 option. Long ago I tried Panorama but really did not find it very helpful. Greatly appreciate all your advice and I am now off to see about Arq 7

1 Like
30

If you decide to go for it have a look at this discussion about tuning Arq. Jeff asks and my answer further down. Still Building my Server and Backup Solution - Backup Solutions? - #9 by fischej

31

Thank you all for your excellent help! I’m limited right now because my surgery has really limited my arm motion, but will soon be leaving the mess that I am experiencing with the current status - can’t even do a spreadsheet because tabs are gone, half the time spaces are not able to be put into text. It’s like my now grown kids have found revenge on me lol. Blessings to you all and I hope when next you hear it will be to tell you all is fixed

32

I have looked everywhere and I cannot figure out how to configure Arq 7 to copy my Macintosh-hd -Datta folder to a backup disk. I do not want io copy it to the cloud, but to a SDD so I can use that to make sure all my items are transferred after I use Time Machine to migrate following the renewal of the iMac OSX. Any ideas most welcome - man anesthesia sure scrambles an old man’s brain lol

33

@paal
I need your help. I have Arq 7 but cannot figure out how to use it to back up my Macintosh HD - Data file to a folder or external drive before I do the reset. I have everything else backed up to several different hard drives as well as two CCC copies on two different drives - I don’t trust my eyesight lol. I would greatly appreciate any specific directions you can provide me, then I will be ready to go. Thank you so much!

34

File>New storage location>Attached disk or network share
Hit Continue
I have no external disk at the moment, but there is an “>” in front of your HD you will have to click that if your backup disk is not listed. I guess you will find it under Volumes if it is not listed immediately.

35

Thank you. Sorry for delay but having health issues. Appreciate your help!