Disable TRIM b4 upgrading to OS X 10.10


NoBoMac

Moderator
Staff member
Jul 1, 2014
2,460
882
Not quite right, since I installed Yosemite without turning off TRIM on my Samsung 830.

Pretty sure a brand new version of the kext gets installed. It's when you enable TRIM without enabling the kext debug/developer boot flag is when the machine bricks.
 

UncleSchnitty

macrumors 6502a
Oct 26, 2007
851
13
I've seen people saying their machine won't boot after installing Yo, or restarts itself, check this:

http://blog.macsales.com/27116-disable-trim-before-upgrading-to-yosemite?APC=XLR8YourMac13

I'm not trying to promote any site, but, I just read this, and they have great tech support for apple compatible upgrades and such.
That was an old issue when yosemite was in the very early stages during beta. If you run a program like trim enabler it has been updated to support yosemite. I updated trim, enabler before yosemite install (like you should do with all software) and it ran fine. No issues what so ever.
 

ibarnett

macrumors regular
Aug 20, 2010
208
39
Gold Coast, Australia
There's a new issue, see here:
http://www.cindori.org/trim-enabler-and-yosemite/
"Important issues
The kext-signing setting is stored in your Mac’s NVRAM/PRAM, a sort of flash memory inside your Mac. This memory can be reset either by accident or by intention (usually by troubleshooting issues with your hardware), causing kext-signing setting to re-activate.
If you try to boot a Trim-enabled system with the kext-signing setting re-activated, you will be met by a gray screen with a stop sign:
prohibitory_sign
This is your system telling you that a driver has been modified, and is not allowed to load.
To avoid this situation, you can make sure to disable Trim before performing any hardware maintenance or PRAM reset on your Mac."
 

UncleSchnitty

macrumors 6502a
Oct 26, 2007
851
13
There's a new issue, see here:
http://www.cindori.org/trim-enabler-and-yosemite/
"Important issues
The kext-signing setting is stored in your Mac’s NVRAM/PRAM, a sort of flash memory inside your Mac. This memory can be reset either by accident or by intention (usually by troubleshooting issues with your hardware), causing kext-signing setting to re-activate.
If you try to boot a Trim-enabled system with the kext-signing setting re-activated, you will be met by a gray screen with a stop sign:
prohibitory_sign
This is your system telling you that a driver has been modified, and is not allowed to load.
To avoid this situation, you can make sure to disable Trim before performing any hardware maintenance or PRAM reset on your Mac."
This is 100% true.
However when doing the upgrade the kext is replaced and trim enabler is in the "Off position" so when you re enable it it enables
Code:
nvram boot-args="kext-dev-mode=1"
for you allowing unsigned kext to boot. But yes you are correct I wouldn't suggest a PRAM reset with trim enabler on.
 

h9826790

macrumors G5
Apr 3, 2014
12,770
5,579
Hong Kong
Not required, TRIM will be automatically turned off every time you upgrade the OS.

In fact, you have to re-enable it after every upgrade, but not disable it before the upgrade.
 

borgusio

macrumors 6502
Jul 22, 2011
258
95
There's a new issue, see here:
http://www.cindori.org/trim-enabler-and-yosemite/
"Important issues
The kext-signing setting is stored in your Mac’s NVRAM/PRAM, a sort of flash memory inside your Mac. This memory can be reset either by accident or by intention (usually by troubleshooting issues with your hardware), causing kext-signing setting to re-activate.
If you try to boot a Trim-enabled system with the kext-signing setting re-activated, you will be met by a gray screen with a stop sign:
prohibitory_sign
This is your system telling you that a driver has been modified, and is not allowed to load.
To avoid this situation, you can make sure to disable Trim before performing any hardware maintenance or PRAM reset on your Mac."
How this applies to the Handoff modified kext files for 2011 macs?
 

benji888

macrumors 68000
Original poster
Sep 27, 2006
1,741
341
United States
Not quite right, since I installed Yosemite without turning off TRIM on my Samsung 830.

Pretty sure a brand new version of the kext gets installed. It's when you enable TRIM without enabling the kext debug/developer boot flag is when the machine bricks.
That was an old issue when yosemite was in the very early stages during beta. If you run a program like trim enabler it has been updated to support yosemite. I updated trim, enabler before yosemite install (like you should do with all software) and it ran fine. No issues what so ever.
If it was an old issue, then the blog post would not have been posted yesterday, after people have been upgrading to public release of Yo.

I do think the issue only comes up when one has used terminal to do some kext changes. I am not familiar with this, tho., and just wanting to help people out who have done this. I got an SSD that does not need TRIM, so, I had no issues, but, again, depending on how old the SSD is, or if one has made special modifications w/TRIM, this could still be an issue.