Which files should I delete in order to be able to boot up an external drive.

Thank you to ALL that have tried to help me! I've tried many things over the past many days and thought my 8 yr. old internal Mac was failing, but then took an old ext hd and erased and reformatted and it works. Unfortunately my existing hd's went to data drives and couldn't be fixed back to start up disks by recovery methods I plan to back up their data then reformat them. It should fix the problem as it appears. I need to learn how to use time machine, so that I could save lots of time and stress that I had encountered. I'll update you when I can. Thanks again

Thank You so much for your help! The error comes up quickly and quickly goes away, so I can't take a pic of it. However, I could search the internet to find an example if you would like? I will check into what your asking, but it's an in Intell i7 Imac. OS Ventura. What you might want to know is the SSD drive info as all the other externals and internals are working. It's just that I can't boot up from this SSD that I have been living in for a few years, but you know Macs better than I do and I appreciate your help!

Does this help?

iMac 27″ 5K

Purchase Date: November 15, 2017

I will see if I can find that error message. It has many lines of info.

Thanks!

Yes, I can boot up from the internal drive. I started using an external when it would cost too much to upgrade the music app. In order to continue to use the music software I bought an external to do everything else on. Thanks.

I set up my SSD external to share files with my other external, so it worked in my favor. I can copy and delete any thing on that drive, but I don't fully understand what container means and it labeled itself, "Big Sure - Data." I don't think I ever installed Big Sur. I have been using Disk First Aid on all of them!

I am able to use the other external in place of my main external. it is close to what my SSD has, but it's super slow in comparison. After it takes forever to boot up it works pretty well, bur some apps are slow.

Thanks

Good idea! Didn't think of that. Unfortunately it will need to wait as it takes so long for the working external to boot up to get back to work that I can't lose the time waiting for it for my job. Will probably do it tomorrow. Thanks.

So I couldn't boot from the SSD still, but received an error log from the other external, which is almost a carbon copy of the SSD and I think is a container for the SSD. The error message at startup was the same as the SSD during startup, but was able to boot up anyway. Below is the error message I received on the SSD and it looped.

Below is what I got from the container disk or I mean the other external that booted up:

panic(cpu 6 caller 0xffffff800092371a): tzinit[16] exited -- no exit reason available -- (signal 0, exit status 2 )

uuid info:

0x1081d4000 uuid = <27b4a78f-a030-39e1-8458-611a8d034b2b>

Thread 0 crashed

RAX: 0x0000000002000001, RBX: 0x0000000000000002, RCX: 0x00007ff7b7d2b658, RDX: 0x0000000000000000

RSP: 0x00007ff7b7d2b658, RBP: 0x00007ff7b7d2b670, RSI: 0x0000000000000000, RDI: 0x0000000000000002

R8: 0x0000000000000000, R9: 0x0000000000000000, R10: 0x0000000000000000, R11: 0x0000000000000206

R12: 0x00007ff7b7d2bc58, R13: 0x00007ff7b7d2bcd0, R14: 0x00007ff7b7d2bc90, R15: 0x00007ff7b7d2bb20

RFL: 0x0000000000000206, RIP: 0x00007ff80b681262, CS: 0x0000000000000007, SS: 0x0000000000000023

Thread 0: 0xffffff9bb1b5ab30

0x00007ff80b681262

0x00000001081d7ff7

0x00007ff80b35f418

Mac OS version:

22H625

Kernel version:

Darwin Kernel Version 22.6.0: Thu Apr 24 20:25:14 PDT 2025; root:xnu-8796.141.3.712.2~1/RELEASE_X86_64

Kernel UUID: 40388BE0-12E1-3C59-9820-A402CA83DB3E

roots installed: 0

System model name: iMac18,3 (Mac-BE088AF8C5EB4FA2)

System shutdown begun: NO

Panic diags file available: NO (0xe00002bc)

Praying I made sense.

Thanks for your help.

Unfortunately I can't find the name of the SSD in the get info and I must have thrown out the box, so I don't know the name or type of SSD it is, but I reinstalled the OS with this error, "Storage system verify or repair failed 69716." I also realize that I haven't been doing a network reinstall as I don't see a globe. Cmd. - Opt. - R. I thought was network recovery, hut it must be the OS on disk.

Thanks

HW Tech, Unfortunately. that error was taken from the usable external. It doesn't come up anymore, but booting takes forever. Also, I did get a clean bill of health from apple diagnostics. I will try drive dx, but it might need to wait....however, I'm still unsure if I can get into the affected drive in safe mode. Faulty keyboard, cord or something? I'll keeo you posted.....thanks so much!

Ok. So last night I unplugged everything, but the affected external drive and got onto the internet recovery system on the net. I did first aid on everything I could see. Affected drive and internal. I tried to reinstall the OS Ventura and got the same error, "Storage system verify or repair failed 69716." After looking it up it appears it has to do with the update process that updates need to be done in small increments, but the examples I saw were full or trying to skip upgrades then was fixed by smaller upgrades, I just wanted tio go back to my last upgrade, which was the last update apple had for Ventura. I believe I kept current.

Thank HW Tech and everybody for your suggestions, but I think I might just find files on the eternal because I can get iinto it, back them up manually as I get time to do so then erase the drive and start over again. At this point in time I can't afford another external to do a time machine backup and I also don't have the time to invest in Drive Dx as I will be moving soon.

HW Tech, You may have something that the internal went bad as the Mac is 8 yrs. old., but it still works great when I boot into it.

Thanks Everybody! I will post if anything comes up!