Problem with MacOS update 10.15.7 2020-001

Make sure you really know what has caused what. Not everyone (maybe the vast majority of users) are not experiencing what you have. I have T5 and T7 Samsung external SSDs and they are both working fine as boot drives for 10.15.7.

This is interesting. Cause I've seen lots of people having exactly this problem. Okay, Lets try to investigate, I start with my setup:

iMac 27" Late 2013 / 3,2GHz QuadCore i5 / 24 GB Ram / 1TB int HD.

System installed on internal HD: Catalina 10.5.7 (all previous updates installed

External Disks:

1. Crucial X8 2TB SSD (System disks, with that it all happened). Splitted into two volumes, one excl for system, apps, user, second for misc data storage. APFS formatted. System installed Catalina 10.5.7
2. Another Crucial X8 2TB SSD, 2 volumes. APFS
3. Drive USB HD 7200rpm, 6TB, 2 volumes, MacOS extended

Running on the fourth USB port via ext. USB 3.2 Hub

1. Seagate Backup HD 6TB, MacOS Extended, used excl. as Time Machine disk
2. WD My Passport HD 2TB
3. Midi/Music Stuff: Nektar GX61 Keyboard, Yamaha AG03 Mixer, Korg nanoKontrol Studio MIDI Controller

When installing the Security Update, I was running 10.5.7 (all updates installed) from the ext. Crucial X8 mentioned above. No issues for long time (or better said, never), everything working fine. The rest of the story is known ...

Anyone else fancy providing his setup to find out more...?

Aah, and maybe just to clear: Not speaking about 10.15.7, but more explicitly about the security update patch 2020-001. So 10.15.7 runs (and always has been running) like a charm. So maybe the original thread title was kinda misleading, or did you install successfully this security update?

Yap I think it's something about his old iMac. Hurts to say, cause it's a lovely workhorse, I always could trust in ;-) But is planned to be updated soon for a new 2020 iMac (or if it stands a while more for my daily biz, till some decent M1) but will live on as a secondary machine anyways ;-)

Maybe the update tried some firmware patch/update too which would explain other issues later on the usb busses. And some strange message popping up out of the blue saying that some firmware update information could be send to Apple for diagnostic purpose. ****** I just agreed before making a a screenshot of this (usually I always agree sending these to Apple, as it's always gold for developers. We keep on with the long search...

I can be wrong, but I guess people with problems (like me) use a older mac with a rotational internal drive? Looks like somehow Boot-ROM /EFI on those machines is screwed for such a setup, as mentioned (or suspected) before.

Hi Elky

My iMac is a late 2013 21.5" (14,3) with 8gb RAM, 2.9ghz CPU, 1gb nVidia GT 750M GPU and 1T internal HDD. It originally came with Mavericks. The latest update on the internal HDD was El Capitan which I stuck with until May last year. I have always been reluctant to update OS until they have been around a while and I wasn't overly impressed with Catalina…

I will check the USB bus which might not support two SSD and an external HDD at boot up. It works fine with just one external SSD and HDD. The third one might be what is causing the problem. Still think the security update buggered my SSD though.

I am wishing that perhaps I should have had an internal SSD installed but I didn't want to take my iMac apart and using an external SSD was SOOOO much easier :-)

I won't be installing an internal now since in a few months I might be getting a newer iMac.

Just for the record, I have the iMac 27' Late 2013 as well, 3TB conventional HD.

(BTW I seem to be one of the very few that managed to install that 2020-001 Security update on the external SSD „somehow“. Also it boots and runs from it (fingers crossed) without unplugging everything. BUT if i change anything connected to USB the trouble starts again, so I better dont touch the very configuration i got now ... very strange.)

I got the same problems when trying do boot from an external SSD after installing the above mentioned security update to Catalina. I‘m using as well an iMac 27’‘ Late 2013, but mine has a 3 TB fusion drive - so this isn‘t starting with 2014 models.

I tried Blackmagic on my drive and I was getting about 400MB/s but it wouldn't let me run it on any other drive since it said I didn't have write permissions??? This don't make sense at all.

Plus I am not convince about this particular iMacs capabilities with SSD drives since I just looked up the specs and it could have been purchased with an internal SSD although at the time it was only a 512mb version (I don't think the 1TB models where available).

I think if Apple didn’t charge four times the price as say a company like Crucial for SSD drives none of these problems would have arisen... A 1TB SSD would cost £100 approx from Crucial and Apple want £400 as an upgrade. Good way to loose potential customers I think?

Important to remember that installing Catalina and up will never erase your data unless you format the drive,

what the installer does is create a new volume AND keeping your previous volume by renaming it “volume name” + DATA,

if you use symbolic links to point anything in catalina to (example large fcp docs, apple audio libraries, etc) upon restart Catalina fsk boot drive will get confused and assume you have two systems resulting in bad reboot into installer,

apple designed catalina to brick soldered ssd drives if it detected external devices used to get around buying a new mac with larger drives, buying accessories apple did not certify as they have agreed on a monopoly with chinese factories to control what accessories work...most of the security updates clearly show that Apple invested a huge effort in these tactics far more then user security, which explains why a 4 dollar adapter stops working after an update.

Totally cool info,

computers are bricked for users with drives soldered unto motherboards because the firmware later effects the power supply etc, ill can share a link about it but cant here as this info was removed a number of times, the person who posted the original was banned as well.

but the cloning info is cool

thank you!

Exactly what happened to me, i updated catalina and both internal (with os) and external drives suddenly appeared wiped, this is an illusion of course (apple) the files where all there inside a volume folder with the “drive name - data” , but i could not find it unless i opened disk utilities and right clicked on the drive then choosing to show it in the finder.

my problem is that this one ext 8tb drive is still in this state with a sort of os and no home user folder lol

any solutions welcomed

I was simply thanking a user for their solution to my problem. Apple is continuing to support older machines and releases security updates to the Catalina OS. Also, while Big Sur is not compatible with my Late 2013 iMac, it is compatible with other machines dating back to 2013. It is my understanding that it is compatible with all machines dating back through 2017.

And finally, if you have a problem with Apple, bring it up to them and not to the members of this forum.

I understand but think about it, apple is releasing osx fixes for older machines to catch up with developers almost near the end life of an upgrade, this means you should expect nit to update whats working fir you now or you shoot yourself in the foot

you will experience the same old trend with Big Sur where 3rd party hardware need to obtain licenses from apple to be compatible and app store developers are trapped in a monopoly, this is not about getting osx to work right for the professional end user but more about greed and keeping the end user ‘s hopes in vain hope..while selling many more devices to rich toy users,