Level 1

4 points

Problems with installing macOS Sonoma 14.5 on external SSD

Hello guys,

My iMac 2019 27" has recently started to have slow start-ups and grey screens. Previously this usually went away after couple tries of rebooting, but now it occurs most of the time when I start up the computer. I have tried clearing the SMC and NVRAM as well as starting the Mac in Safe Mode. of the iMac's back helps to go past the grey screen and results in massive dust balls coming out of the computer's speakers/fans :)

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, 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.

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".

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 :)

So could anyone kindly help me out with this issue? Like what are the exact commands and do I have to include the exact names of the external drivers or the locations of the downloaded Sonoma? I would appreciate if I could prolong my iMac's life by using it via external SSD.

Thank you.

E: While writing this, the expected time jumped from 2 hours and 32 minutes -> 12 hours and 55 minutes :)

E2 :

[Edited by Moderator]

iMac 27″

Posted on Jul 25, 2024 4:44 AM

Top-ranking reply

HWTech

Level 9

68,756 points

Posted on Jul 26, 2024 8:24 PM

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.

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24 replies

Yeffersson Author

Level 1

4 points

Jul 29, 2024 7:57 AM in response to HWTech

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

If the HDD fails, can I unmount it in Disk Utility without physically tearing my iMac apart? I'm just ruling out that it wouldn't affect the overall performance and I could use my SSD and extend my Mac's lifetime by couple of years.

Yeffersson Author

Level 1

4 points

Jul 29, 2024 10:30 AM in response to HWTech

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

Yes, I removed all of them so it would be in the original condition.

Do you have an idea if this would fit my MP600 Elite for PS5 so I could use it as external SSD? I have placed an order for Kingston XS2000 500GB, so I would most likely return it, because MP600 seems to be a lot faster.

What comes to my current SSD - maybe I'll erase it and make a new TM backup, no? Before formatting everything.

HWTech

Level 9

68,756 points

Jul 29, 2024 6:01 PM in response to Yeffersson

Yeffersson wrote:

Do you have an idea if this would fit my MP600 Elite for PS5 so I could use it as external SSD?

I don't know since I don't see enough details on the Corsair website for which M.2 connector key the MP600 SSD uses, plus some SSDs are different lengths, so the enclosure must support that length as well.

Personally I would not go with Orico. I think I may have tried to use one of their enclosures a long time ago and it was not compatible with a Mac at the time. I personally prefer Plugable, StarTech, and OWC Mercury products although there are also some other brands that are also Ok. The OWC products don't always allow the necessary communication to access the health information from the drive, otherwise they are usually good quality products.

Not all devices are compatible with a Mac although most should be compatible. Macs are picky about the drives used for booting as well.

Yeffersson Author

Level 1

4 points

Jul 31, 2024 12:35 PM in response to MartinR

Thanks for the reply.

To address the issue, I'have bought third external drive. Now I have (1) Kingston XS2000 1TB for running the macOS, (2) Kingston XS2000 1TB for TM and (3) Seagate 2TB HDD for TM as well to make sure valuable information is safe.

The idea is to start from the clean computer and not to clone the old data. I'll keep the data on two separate external drives. Now while the Sonoma 14.6. is still downloading before I've created a bootable USB drive - how to format the XS2000 then? I was living in an understanding based on YT videos that Mac OS Extended (Journaled) is mainly used with older OS and now APFS is fine. Now as I have formatted the XS2000 as APFS and GUID, what format you recommend to use then?

Thanks.

MartinR

Level 7

24,216 points

Jul 31, 2024 2:52 PM in response to Yeffersson

Yeffersson wrote:

So the fact that my Fusion Drive is formatted as APFS is not something I can change to make my Mac faster, right?

That's right, if you are running Catalina, Big Sur, Monterey, Ventura or Sonoma your system drive must be formatted as APFS even if it's a Fusion drive. That includes any external SSD you plan to install macOS on.

Jul 31, 2024 4:34 PM in response to Yeffersson

Just to add a bit about my own experience, I have a 2013 iMac that came with a Fusion drive. I now have it running the OS from a SSD connected via USB. The difference in performance speed is quite amazing. I think part of that comes from having the OS using the SSD for all its virtual memory needs, thus improving the speed of everything it does.

Yeffersson Author

Level 1

4 points

Jul 27, 2024 3:15 AM in response to franzkaiser

Thanks for the reply! I ordered new Kingston XS2000, but in smaller size (500GB). That should be enough for running macOS on it.

Yeffersson Author

Level 1

4 points

Jul 28, 2024 9:59 AM in response to HWTech

EtreCheck Report

Yeffersson Author

Level 1

4 points

Jul 31, 2024 5:01 PM in response to franzkaiser

Thanks for sharing your experience. Really looking forward to running the OS on the external SSD.

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Problems with installing macOS Sonoma 14.5 on external SSD