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I'm starting to learn more about the mac os x internals. Now i want to load and unload some kernel extensions.

I startet to load the MS-DOS file system via

sudo kextload /System/Library/Extensions/msdosfs.kext 

I can check this by typing

kextstat | grep msdos 

The command output shows the loaded kext-file. But when i want to unload the MS-DOS file system:

sudo kextunload

I get only this message:

Can't create

What is wrong with the kextunload - line above?

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up vote 14 down vote accepted

kextunload can use the full Kernel Extension path, just like kextload.

sudo kextunload /System/Library/Extensions/msdosfs.kext

If you want to use the bundle identifier – the one listed by kextstat –, use the -b switch:

sudo kextunload -b
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I get Can't create –b. if I use it... I'm on 10.8.3. – m_gol Apr 5 '13 at 13:52

i had the same problem (Can't create –b. ; Can't create trying "sudo kextunload –b" on os x 10.9.5

but after i used the full path (sudo kextunload /System/Library/Extensions/IOUSBFamily.kext/Contents/PlugIns/AppleUSBFTDI.kext/), it worked...

that only happens on some kexts, for eg on other kext (/System/Library/Extensions/FTDIUSBSerialDriver.kext) , it works perfect with "sudo kextunload -b com.FTDI.driver.FTDIUSBSerialDriver"

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kextload man page can give you details. Here is the command I've been using:

sudo kextload /path/to/file.kext

OR kextutil man page, this tool is useful for get some debug messages if there are errors in the loading process.

sudo kextutil /path/to/file.kext

And of course, the kextunload man page in the other answer. Here is the command I mainly use since I don't like to write out the entire bundle id:

sudo kextunload /path/to/file.kext

You can also use kextstat to verify if your kext file has been loaded:

kextstat | grep -v apple

This will list all third party kexts as long as 'apple' is not in the bundle id.

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