How do I make a bootable external drive to repair a MacBook Pro internal hard drive?

little shiva wrote:

I bought a 1TB external drive (Seagate One Touch, supposedly already formatted for Macs and ready to use),

that very well could be the root of your problem. when you use software from just about any manufacturer for their storage device you run the risk of that same software not being compatible with macOS updates / upgrades. it can cause the software to stop working. at best this will cause you a headache. at worst it can render your data inaccessible. it is always best to use disk utility to erase and format a drive before use to remove any preloaded software.

since you are using such software, i think your options are somewhat limited. 

you may want to contact seagate and see if there is an update for their software.

alternatively, if you have a backup you can revert your macOS to the version of macOS that the drive was working on and transfer your data to another storage device and then erase and format the seagate device before putting it back into service.

While cloning to make a bootable external drive is now a real challenge, you could directly install Sonoma on the external drive & then use Migration Assitant to migrate your user account(s), apps & data from your MBP's internal drive, essentially giving you the 'clone' you desire.

You should be able to download the Sonoma installer from the App Store. If that doesn't work, there is another way to download the installer using Terminal; let us know if you need information about how to do that.

First, make sure you have a good backup of your data on another drive. Then:

• Connect the Seagate drive to your MBP
• DO NOT use any Seagate software with the drive
• DO NOT use the Drive Genius software to make a bootable external drive
• Use Disk Utility to format the Seagate drive as APFS. (Not APFS encrypted or APFS case sensitive). Make sure to select GUID Partition Scheme & APFS format.

• Then run the Sonoma installer & install it on the external drive.
• Once the install is complete you should be prompted to migrate accounts, apps & data from the internal drive. (Note, this is a copy process, it does not disturb or delete anything on the internal drive.)

when drive genius was a very important piece of software, drives cost north of US$1000, and backup were on CD or floppies.

Today, these are obsolete:

• backups to floppies

• backups to CDs

• the idea of running without a Recent, Trusted, Full backup on a nearby Drive

• Using Drive Genius, which does not look like nearly as much or a Genius as it did when issued.

you may indeed need a new drive. Or maybe you just need to run Disk Utility and fix that one up. or maybe you would LIKE to have a new drive.

step 1: make certain you have a reset Trusted disk based backup. Time machine is already included inside your Mac.

disk Utility checks for problems in your Mac's Directories. it does not check for problems such as bad blocks out in the sea of data files.

That's what backups can NOW cover, because the prices of drives has dropped enough so that everyone SHOULD have backup copies of their files.

Some other things are changing, slowly:

It used to be that having bootable macOS, and/or having MacOS included in your backups, was thought to be important. But re-installing MacOS has always produced an EXACT replica of the invariant 'pure code' parts of macOS anyway.

With the additional restriction that you must re-install onto the crypto-locked System Volume using fundamental sources, having a copy of macOS 'as it used to be installed' is LESS important, and being able to fetch a copy of MacOS and Actually Install it has become More important.

MacOS has always been re-installable and/or upgradeable IN PLACE. By design, even its re-writing of over 350,000 files is intended not to disturb your User files or settings in the slightest.

I used to run Drive genius, Disk Warrior and other Utilities. What I have learned from running them is that there will always be a few files that show I=up as a problem. but they tend to be not important files or they can be restored from backups easily.

Drive genius and Disk warrior and NOT needed once we have adequate backups, and the price of drives dropping so much in the last decade or so has fixed that.