A log location on the production SAP system was full. He said he wanted to "clean some stuff up; move some files and directories some place else" His login was not working (after a recent upgrade) I asked, which files, and where are you going to move them? He said to /dev/shm (shared memory/RAM; he picked this b/c it "had 20G free"). I said, that's a really bad idea, they would be gone if the system rebooted 10 seconds later, and we don't have it setup that way even (not mounted to a tmpfs filesystem). Also that running applications don't often take kindly to having files pulled from underneath them.
He found another system with the log location NFS moutned, moved the files to the /dev/shm device on that host. On top of that said files were locked open by a process on the server. That left them in never never land, and in a quasi state on the server. At any rate, thankfully the files were not really needed, and now we have to have an outage to get the space to free from the real filesystem. LSOF shows the open inodes, ls by inode does not.