Q&A: Spyder versus RAID

Q When I installed a Spyder screen calibration system on my iMac, it could no longer see its WD My Book Studio II RAID drive, even after re-installing the WD software. What happened?

A Having looked through your logs, I think this is most likely to be a clash between the kernel extension software to support the Spyder, and that for the RAID drive.

Restart with the Shift key held to disable non-Apple extensions, then remove the files IOFireWireWDHID.kext and CNQL1208_ClassicNotSeize.kext from /System/Library/Extensions, which are generating errors in your logs. Restart with the Shift key held again to force the rebuilding of caches, and install the latest version of the Spyder software, restarting on completion.

If Disk Utility cannot then see the RAID, try downloading and installing the latest version of the software supporting the RAID.

If that still does not work, contact WD support. Sometimes hardware fails coincidentally at the same time that you install new software, and it is possible that your RAID drive has done just that. However if the clash of KEXTs continues, they need to know about the problem so that they can fix it.

Comments Kernel extensions, KEXTs, do what they say, and extend the core support of OS X at a low level to cover third-party hardware devices. Unfortunately because they work low down, they are also known for causing conflicts.

Here the two devices from different vendors rely on their respect KEXTs in order to work. This type of RAID drive is dependent on its proprietary Kernel Extension, just as your display calibrator depends on its KEXT. Unfortunately if the respective suppliers cannot fix the problem you may have to choose which device you want to work.

One temporary workaround might be to perform display calibration without the RAID support installed, then uninstall the Spyder support and install that for the RAID. Whenever you wanted to recalibrate your display, you would then have to uninstall the RAID and reinstall the Spyder support: far from ideal, I am afraid, but it could buy some time for the vendors to resolve the problem, perhaps.

Updated from the original, which was first published in MacUser volume 30 issue 08, 2014.