#appleraid

Options for securing external storage in OS X

The default approach for storing files on drives other than your boot drive is to get an external storage device and then copy your files to it; however, by doing so you leave open the possibility of someone getting your drive and accessing your data. To secure the files you place on such drives, there are several approaches you can take, including encrypting files or the drive itself, and using…

I decided to remove the Apple Software RAID, which consists of two 1TB HDDs, on my Mac Mini Server  (Mid 2012). After booting the System via Internet Recovery ( CMD + SHIFT + R) and starting up Disk-Utility to remove the RAID-Volume, DU won't do that, because it was not able to unmount the Disk. Why?!

I checked with Terminal which process blocked and found, that notifyd was holding a filehandle on that volume (only the volume mountpoint). Killing notifyd caused a short system-hang follewed by 20 open filehandles on that Volume. Don't try to kill notifyd permanently (via "kill -ill" and some combination of launchctl commands - your system will freeze).

Finally I tried to remove all things from that volume ( cd /Volumes/OS && rm -rf * && cd /) and killing notifyd once more. The process re-spawnd and aquired a filehandle on the volume once more - but I gave Disk-Utility another try. It complained again that it was not able to unmount - but did it nevertheless.