Prevent Drobo from constantly accessing disks under Mac OS X 10.5
I had that problem for some time. With little help from Data Robotics Inc.'s support who just suggested that 'some program is accessing' the Drobo and therefore my problem isn't a Drobo problem.
My configuration:
Drobo 2 connected to Mac Mini (early 2006 version) via FireWire (400 to 800 adaptor)
Mac OS X 10.5.6
Steps to solve the problem that could help someone who has the same problem: There is constant disk access on the Drobo, which in turn never sleeps, the fans run constantly and it's making some noise, too.
1) Monitor the file system in Terminal with the command: sudo fs_usage -f filesys
This shows you all processes that have file system activity. Helps to narrow down the source of the annoyance. In my case it was a process called 'build_hd_index' which I first wrongly connected to Spotlight. But Spotlight uses its own indexing. build_hd_index is an indexing done by Apple Remote Desktop 2.x and 3.x. Which you completely DON'T NEED if you're not using Apple Remote Desktop. I tested on my system here and it had no effect on Screen Sharing that's built into the Finder, though.
2) There is an Apple Support Document on how to disable the process within Apple Remote Desktop: http://support.apple.com/kb/HT1088 (if you're using that program at all. I don't but did earlier, therefore that dreadful process still existed)
The document mentions that you should delete the ARDAgent plist-file at: /Library/Preferences/com.apple.ARDAgent.plist
(In my case that only existed only in my User directory, not in the 'root' Library)
This TEMPORARILY disables the build_hd_index process.
3) To constantly disable our friend build_hd_index go to the Terminal and disable the execution privileges with this command: sudo chmod a-x /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/build_hd_index
That's it. This has done the magic for me. Would be interesting if anyone else had that problem and if that solution worked for you. However, as I don't have experience with other systems and I got that information from sources whose reliability I couldn't verify, I take no responsibility whatsoever if you follow these instructions. I can only tell that they worked for me! You can find a discussion on that subject at http://dfbills.com/display/383. That's where I got step 3 from, the information is also quoted by other sites that you find when googling 'disable build_hd_index'.
Have fun (and silence)!
