After upgrading a server to El Capitan and Server 5.0.4 I noticed that a process was constantly taking 50-60% of the CPU and showed no signs of calming down after running a couple of days. The process is
Googling and digging around I discovered those processes, specifically sdmd, are related to File Sharing. The executable is found at /Applications/Server.app/Contents/ServerRoot/System/Library/PrivateFrameworks/ServerDocsMaster.framework/sdmd. I recruited my super-sleuthing friend @mikeymikey to take a look. He found
“..it generates thumbnails and basically does a lot of prep work for iOS devices that can’t look up all this information themselves for a large directory. It basically looks like “mini Sharepoint” for iOS. If you have huge shares you never intend to make accessible via iOS, I can see how this thing would put a ton of load on your devices. And it looks like it monitors the directories for change, too, so it’ll just keep coming back.”
I don’t want that.
Posts to various forums reported that removing and re-adding all the shares made the problem go away. Instead of going to all that work I discovered that disabling iOS access on the shares made the sdmd process stop. By default, when upgrading to Server 5 all my shares were enabled to be iOS accessible. Thanks Apple!
To turn off iOS access, open the Server.app and navigate to the File Sharing service. Highlight a shared folder and click the pencil button to edit it. In the share preferences there is an iOS checkbox. Uncheck it. Do that for all shares and the sdmd process will stop.