Volume Hash Mismatch Detected macOS Should Be Reinstalled

Volume Hash Mismatch

Hash mismatch detected on

volume disk1s5.

macOS should be reinstalled on

this volume.


I have gotten this message a couple of times. The most recent time I was on the web creating a listing on eBay.


I am not sure how I go about re-installing the OS on my iMac?


Here is a screen shot of the message.


Thanks for the help!

iMac 27″

Posted on Oct 26, 2023 11:59 AM

Reply
1 reply
Question marked as Helpful

Nov 5, 2023 4:30 PM in response to G4RAY

@P. Phillips knows me well. I also knew he would have links to other threads reporting the same issue.


Unfortunately unless the Apple service diagnostics report a failure, Apple may not do anything more than have you perform a clean install. The Apple service diagnostics are a bit more involved than the consumer diagnostics assuming the tech actually runs the more advanced ones, but even the more advanced service diagnostics are extremely limited. It is rare you will find an Apple tech who knows how to actually do real world troubleshooting when diagnostics don't reveal an issue. A good tech gets very creative, but unfortunately Apple's training & service guides are very minimalistic.


You can try creating & running a bootable Memtest86 USB stick to see if any memory errors are reported. This memory test is a bit more intensive than anything Apple has, plus the free version of the utility is able to be run for 4 loops which is much longer than Apple allows their own service diagnostics to run. Unfortunately Apple will probably not care about any failures reported by Memtest86, but at least you will have confirmation of the problem if it reports an error. Perhaps a tech for an Apple Authorized Service Provider will be a bit more inclined to consider the Memtest86 errors, but probably only if the tech is familiar with troubleshooting non-Apple systems where tests like this are more common. Even Memtest86 can fail to detect bad RAM. I have run Memtest86 on multiple Apple laptops from 2012 to 2019 models. The only time I've seen it report an issue is when I suspected bad memory and confirmed an identical model did not report any issues.

19 replies

Nov 4, 2023 10:41 AM in response to MrHoffman

Thanks. I had to buy a new external drive to run Time Machine which now has mutiple backups of my computer on it.


So the next step is re-inistalling the OS.


When I follow the link you shared I am not sure about one thing. If I choose to install the latest version of the OS how do I get my current desktop, apps, etc. that are on Time Capsule inserted into the new OS ?


Thank you!



Nov 4, 2023 11:02 AM in response to G4RAY

If the re-install ends up becoming an erase-and-re-install, the following (highlighted) section is where the Time Machine backups get migrated / restored / reloaded, as part of the first startup of the new macOS install.


Setup Assistant loads your content from the backup.






Note: If you decide to skip the first setup and skip running the setup assistant (setup assistant is effectively the same as migration assistant, run during the first startup, and which also migrates previously-installed apps), then pick your first newly-created login at first startup different than the login name you want to restore. If you have a login called MyName that you really want to use, do not create a new MyName at that first login after an erase-and-install, as now you won’t be as easily able to migrate your previous backup of MyName. Pick MyAdminName or other such name as that first new user after the erase-and-install, and use that, and then you can migrate in your MyName files later using Migration Assistant.

Nov 4, 2023 11:17 AM in response to MrHoffman

Thanks!


And I am a little confused about what you said at the bottom about log-in names.


What is the easiest way to install a current iOS, preserving my files and settings, without re-installing my current iOS?


Sorry if I seem a little slow. I don't want to screw this up and create more problems for myself.


Thanks!

Nov 4, 2023 6:37 PM in response to G4RAY

FYI, most likely this issue is caused by a hardware failure, most likely bad memory. There have been numerous posts on this forum and several people have confirmed Apple replaced the Logic Board for a memory failure. If it is due to a hardware failure, then it is likely you will see this problem recur after some time even after a clean install of macOS.


You may want to try running the Apple Diagnostics to see if any hardware issues are detected. Unfortunately the diagnostics rarely detect any issues even when there is a hardware failure, but it never hurts to check just in case it reveals an issue. It may save you a lot of work.

Nov 5, 2023 1:16 AM in response to G4RAY

To add to a posting related to a possible Bad RAM Module


In most of the situation in links below.


The RAM Module has failed or is failing


The only true way to determine this, is to have the machine Evaluated in an Over Night Stress Test by Apple Store or Apple Authorized Service Centre


Volume hash mismatch, cannot reinstall MacOS


Monterey rev 12.4 - Hash mismatch


Please help - Terminal.app keeps crashing upon reopening - macoS Monterey version 12.4


Volume Hash mismatch


Strange Disk Space Issue


RAM Failure 

Volume Hash Mismatch Detected macOS Should Be Reinstalled

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