Using Virtualbox 5.1.26r117224 (latest at this time) on Ubuntu 14.04. Also tried with the latest Virtualbox 4.x.
To randomize the UUID of a virtual disk for VirtualBox, I'm using vboxmanage sethduuid [filename] as usual. Normally this only takes a second or two. But now it's hanging for about 30 minutes, and the process has the "D" (blocked on kernel call) state in top. I can't kill it, even with -9. Strangely, it works on one VDI but hangs if I copy that then run the command on the copy. I've tried several times to make sure. I think it's also fast if I've started a VM from that VDI before, but I'm less sure about this.
I don't think it's a disk problem. I can access files on that disk and even delete the VDI it's operating on. My guess is the command is executing some ridiculously long kernel operation to set the UUID under certain conditions. Has anyone else encountered and fixed this?
Edit: Also tried cleaning the disk cache to make sure that's not a variable here. Suspected at first that the original VDI was only fast to edit due to it already being cached.
