Problems with installing macOS Sonoma 14.5 on external SSD

Continued....

I have read that some have fixed this issue by entering manual commands in the terminal. I'm a rookie in these things and worry that I might cause more harm than actually solve anything :)

It won't fix anything unless you are trying to create a bootable macOS USB installer which requires the use of the command line. Otherwise, the command line won't help here except perhaps to gather more information, but I don't think the latter is needed quite yet.

The picture of the installer log shows that the installer cannot convert the file system. I don't know why you are getting this error if you erased the destination volume as GUID partition and APFS (top option). There appears to possibly be some other issues with the installer before that, but I cannot tell anything else from the part shown. If you are running the installer from within macOS of the internal drive, then that probably won't work due to the slowness you reported.

You will need to attempt to install through Internet Recovery Mode (Command + Option + R), or by using a bootable macOS USB installer. You should already have modified the security settings of this Mac to allow for booting from USB devices by using the Startup Security Utility. You will likely find using a macOS USB installer will be simpler than dealing with Internet Recovery Mode where you add in many more unknowns....plus you are more likely to experience a time out with the installer when using Internet Recovery Mode.

I highly recommend you purchase another USB3 SSD to use as the external boot drive so you do not further risk your TM backups. If you only just purchased that Kingston drive and have another TM backup drive you've been using, then you should just erase the whole external SSD so only macOS is on that external boot drive. Do not compromise your backups at all if you value your data.

I think you need to troubleshoot the original performance issue first. Besides running the Apple Diagnostics and using DriveDx, I would recommend running the third party app EtreCheck and posting the complete report here so we can examine it for possible clues. Once we have the details from these items, then we may be able to offer other advice moving forward.

A shot in the dark, but try to erase the device as FAT (MBR), and then to APFS (GUID). As described earlier, in Disk Utility click "View" and select "Show All Devices" and erase the topmost device. That might more properly erase the partition table. Then try to install macOS to the one and only volume on that device.

Yeffersson wrote:

I tried to run the Repair Tool in Disk Utility, which says the might be something wrong with the disk and starts the repair and claims to have fixed the problem, but the issue persists and appears every time I run the repair. For me, this is an indicator that there might be something wrong with the HDD.

Not only that HDD appears to be faulty, it is also **** slow. If I recall correctly, the speed varies from 100mb/s - 250mb/s. So to kills two birds with one stone,

You can check the health of the hard drive if you have a Fusion Drive setup by running DriveDx (free trial period) and posting the complete text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar. Feel free to also post the health report for the SSD as well.

Did you run First Aid while booted into Recovery Mode? You should run First Aid on the hidden Container. Within Disk Utility you may need to click "View" and select "Show All Devices" before the hidden Container appears on the left pane of Disk Utility. I would also run First Aid on the Fusion Drive item as well.

Try running the Apple Diagnostics to see if any hardware issues are detected. The diagnostics rarely detect problems, but it never hurts to check.

So to kills two birds with one stone, I partitioned my new Kingston XS2000 1TB in two partitions - one for Time Machine (90%) and rest for macOS (100GB). They are formatted AFRS use GUID Partition Map. I backed up my computer using Time Machine and double checked that everything is safe by using iCloud as well.

That is a terrible idea to partition any drive, but especially so for a TM backup drive. If this was an existing TM backup, then you risk corrupting the backup with resizing the partitions. The other reason multiple partitions is a bad idea is that most people later discover one or more partitions are too small.....that then requires a complete wipe & recreation of the system. If you want the ability to have separate areas on the drive with an APFS file system, then you can instead create a new APFS volume which does not have the same problem since the storage pool is shared between all APFS in a single Container, but you still have the separation of items which can be mounted & unmounted just like partitions.

However, even using multiple APFS volumes on a TM backup drive is a terrible idea for one more reason. If you are backing up the data from the 2nd volume to the TM backup on the first volume, then what happens if the drive fails? You lose the data twice with one hardware failure.....that does not seem like a backup to me since a backup should be available in the case of a drive failure.

Besides all the issues I've just mentioned, the likelihood of corrupting the TM backup increases because the drive is being used for multiple things now which increases the chances of something going wrong.

Backups of the Apple USB-C Macs are more critical than ever before since there are so many more new ways to permanently lose access to the data on the internal drive due to all the hardware, software, and security changes. Even an expensive data recovery service is unlikely to be able to salvage any data. This is why I am so adamant about this.

Plus 100GB for macOS is just not enough these days except to use as a test drive for troubleshooting your iMac.

First, I downloaded macOS Sonoma 14.5 from App Store, but the installation freezes immediately. The bar shows that installation is 3/4 complete and says "About 3 hours and 32 minutes remaining". And it stays there till infinity.

I tried some tips I collected from this site, but without a result. So I entered the Internet Recovery Mode and tried to reinstall the macOS and simply choosing the external SSD and the correct partition, which shows up in the Menu. Unfortunately, the very same thing happens. Now, however, the bar is 4/5 full and the time is "About 2 hours and 32 minutes remaining".

Sometimes a hard drive failure can be so severe that it can affect system performance even when booted from external media.

I don't see anything outstanding in the EtreCheck report other than it took a long time to generate the report.

Some of the crash reports listed in the report are associated with the drive (Finder, Spotlight, backup) so I would suggest checking the health of the internal drives by using DriveDx (free trial period). Post the complete DriveDx text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar.

Also, run Disk Utility First Aid on the Fusion Drive item and also the hidden Container. Within Disk Utility you may need to click "View" and select "Show All Devices" before the hidden Container appears on the left pane of Disk Utility. Even if First Aid says everything is "Ok", click "Show Details" and scroll through the report to see if any errors or warnings are listed. If so, then run First Aid again until they are gone. If the errors remain after several attempts, then run First Aid while booted into Recovery Mode. If the errors still remain after several attempts while booted in Recovery Mode, then you will need to erase the Fusion Drive followed by reinstalling macOS & restoring from a backup.

Lastly, you can try rebuilding the Spotlight Index using the instructions in the following Apple article:

Rebuild the Spotlight index on your Mac - Apple Support

I would also suggest running the Apple Diagnostics to see if any hardware issues are detected. The diagnostics don't usually detect issues even when they exist.

Did you perform a memory upgrade on this iMac or did that 64GB of memory ship with the iMac from the factory?

I don't really see anything with the health of either drive.

The First Aid scan does have a lot of issues with the Time Machine backup snapshots. Unfortunately I cannot tell if there are also issues outside of those TM snapshot. Since those TM backup snapshots are not mounted, they really should not be causing any problems, however, all those errors does make it hard to know whether there were any issues with the main APFS volume.

You can try deleting those four APFS Time Machine snapshots and running First Aid again to see if any warnings or errors remain. Here is an Apple article for viewing & deleting APFS snapshots:

View APFS snapshots in Disk Utility on Mac - Apple Support

When you swapped in those 2@4GB memory modules did you remove all of those 16GB modules?

In looking at your Etrecheck report (Jul 28, 2024 12:59 PM in response to HWTech) here's what I see:

The underlying problems with your iMac's performance are that 1) it's a Fusion drive using a traditional spinning hard drive, 2) the drive is nearly 90% full and 3) it's formatted as APFS. None of these things is kind to performance. All three factors, individually and especially together, explain the performance problem and the issues trying to install Sonoma.

All traditional hard drive performance declines as you fill the drive. For most people the decline in performance isn't noticeable until the drive is over 50%-60% full; but by 80% full nearly everyone notices reduced performance. After 90% you can look forward to the system grinding to a halt at some point. Worse, APFS spreads filesystem metadata all across the platters, which causes significant head movement and the drive will get slower and slower way beyond the impact of conventional fragmentation.

Backup the data, make a bootable Sonoma USB, erase the drive and clean install from USB drive!

I have read complaints by others that are similar to yours. The issue appears to be the partitioning of the SSD to use it for both Time Machine and the start-up disk. This apparently is not acceptable for MacOS. While it requires additional cost, I suggest purchasing a separate disk for one of these functions, so that the start-up disk can have its own domain free of interference.

Yeffersson wrote:

Now as I have formatted the XS2000 as APFS and GUID, what format you recommend to use then?

All versions of macOS since Catalina require the system drive to be formatted as APFS, so if you plan to use the XS2000 as your boot drive, it must be formatted as APFS.

FYI, it appears the discussion has now moved to this new thread:

Can't install macOS on external drive - Apple Community

Yeffersson wrote:

You made me doubt the state of my TM backup. How can I check for the files to

be sure they are not corrupted? Maybe I just wipe the whole SSD and start from scratch and make a new TM backup.

Here is an Apple article:

Verify your backup disk on Mac - Apple Support

Chances are if the backups are still updating and if you can navigate the TM backups through the TM interface, then the backups are probably Ok.