How to Back up & Restore Your Kexts Before OSX86 Upgrades.

20 May 2009 by Vinay 8 Comments

Kexts, or kernel extensions are drivers that are installed to /System/Library/Extensions/.Kext files often have the “.kext” extension and allow for extra hardware support and and in the case of OSx86, to replace Appleʼs original drivers with ones that are optimized for use on PCs. Leopard holds kext files/folders in the /System/Library/Extensions folder, at boot time the relevant kext are uploaded from Extensions.mkext this is a cache folder that contains kext related to the installed hardware. If you loves your hackintosh then take a full backup of your kexts because some kexts may disappear after the update procedure.

For making backup of your Kexts open Terminal and type in these commands:

sudo -s
[enter password]
cp -r /System/Library/Extensions /System/Library/Extensions.backup
cp -r /mach_kernel /mach_kernel.backup

For restoring your Kexts open Terminal and type in these commands:

sudo -s
[enter password]
cp -r /System/Library/Extensions.backup /System/Library/Extensions
cp -r /mach_kernel.backup /mach_kernel

8 Comments »

madoc1 said:

where the ktext are saved?

# 22 May 2009 at 2:29 am

Vinay Prashar said:

@ Madoc1 the kexts will be backuped in mach_kernel.backup file you can’t access it bcause it is a system file but you can restore it again by typing the second command given in the post above.

# 22 May 2009 at 10:29 am

Anthony said:

Why do I get the following when trying to run this command ?

cp: /system/library/extensions.backup: Permission denied
cp: /system/library/extensions: unable to copy extended attributes to /system/library/extensions.backup: Permission denied

# 20 June 2009 at 9:56 am

Robert said:

Anthony, your getting that because you must have forgotten the first part sudo -s

hope that helps

# 27 June 2009 at 6:43 pm

Alex said:

Missing something very important here… the steps or an alternate procedure to boot the OS without crashing so you can, then, restore the darn kexts…
-Alex

# 12 July 2009 at 12:57 am

BL3SSED1 said:

Hi, I’m using iPC 10.5.6 when I upgrade to 10.5.7 or 10.5.8 the video no longer works. How can I use this backup and restore method to restore the .kext that was installed during the original install (before the upgrade) I’m using use the intel 915GMA chipset.

# 20 November 2009 at 9:24 am

anmol said:

Does anyone have a copy of the vanilla SL 10.6 or 10.6.1 extensions ?
I tried different things to get stuff to work on my netbook, now I have mesed things up–
Wish I had backed up my extensions