Bricked my iMac?

[ErikGrim]

In a very weird spot. After a successful upgrade without any hitches everything ran smoothly. Until it didn’t. Suddenly everything ground to a halt, webpages wouldn’t load. Activity monitor showed logs being written a mile a minute (some process writing to a log, whose only reference was a corrupt system install).

Also the bold version of the system font showed as question marks so something was going on with the fonts. Logged in to a clean profile and everything seemed fine. Deleted the offending log files and all caches and logged in to my main account. Same issues.

Cleaned my caches and reinstalled the system, seeing as that had fixed the same issue three years ago from the Apple discussion thread I found (I’ll find the process / log file I googled, something to do with symlinks).

Came back to the iMac two hours later and found it in good shape, only backing up 21Gb of data to my time capsule, something that had failed in my previous install. Ah, I thought - I must just have missed that it was backing up and that’s why it was slow.

But alas. As soon as I stopped (skip backup - or pause really) everything went south. Beach balls everywhere, web pages stopped loading. Had to force a restart. Fans blowing at full speed, weird things happening like getting to the login screen and then going back to the black loading bar with a stuck loader, yet operational cursor.

Tried all the loading tricks, uncoupling external devices, verbose loading, recovery mode, which sometimes got me nowhere and sometimes got me to recovery mode. Disk utility failed at repairing my main disk.

Right now I am installing fresh again. Never experienced anything this strange and unsettling in any of my 30 years of being a Mac user. I just hope this install will get me back to a working desktop at least :/

Anyone else having problems with this?
[doublepost=1496750523][/doublepost]For the record I am well aware of the risks of beta testing having run every beta going back to Copland, as well as the risks of upgrading entire file systems. Just want to see if this is a fluke or a widespread problem.

 

[bbfc]

High Sierra installed perfectly fine on my MacBook Pro but once logged in it was so slow and wouldn't really respond to anything. Tried reinstalling but it didn't work. Nothing worked. I'm now back on Sierra.

Activity Monitor showed my Memory Pressure quite high (orange), and it never changed. I've never experienced this with Sierra or any previous version. Even now when I'm on Sierra - installing updates, indexing, download iCloud Drive stuff, browsing the web - it's all green.

So strange!

 

[ErikGrim]

After third reinstall I am back on a blank account (for now). These are the processes that seem to pile up the most disk writes:

Especially coresymbolicationd seems to be the main culprit grinding the OS to a halt with disk writes to a log at /System/Library/Caches/com.apple.coresymbolicationd

In the main account I'm getting a lot of FontD crashes. And in general there seems to be a lot of xpc.launchd timeouts.

 

[Belazor]

In a very weird spot. After a successful upgrade without any hitches everything ran smoothly. Until it didn’t. Suddenly everything ground to a halt, webpages wouldn’t load.

I'm having similar problems, at first I thought it was a Safari bug but I tried Chrome and it too won't load web pages when this happens.

Then, I tried some other internet-connected apps such as Discord, and it too would crap out when this issue occurred.

I wish I could provide more information, but Console.app doesn't work, it chain-crashes, so I don't know how to access the log files now.

Update: I reinstalled (not clean install, just a normal reinstall) via Recovery Mode, and web browsing appears to work for me (~1 hour of testing). Furthermore, Console.app now works as well.