Disk utility crashes(?) OS X

[subtektor]

Hi.
I'm currently using niresh' iso to run osx in a virtualbox, as it's the only way I know. Anyway, I'm trying to get yosemite on an usb drive.
But whenever I open the disk utility and format a partition on the USB drive, the whole OS simply just stops. Actually looking at the HDD icon in Virtualbox it seems as if the disk just shuts off so I'm stuck here with this frozen image of disk utility [gyazo,com/6085bebd51e7d64aabe0154cc6903cdc].
Restarting the machine works & all, but using the disk utility will only result in the same thing happening again.

Any ideas as what's causing this?

[Perryg]

Post the guests log file ( as an attachment )

[subtektor]

Post the guests log file ( as an attachment )

Hey! Where do I find the guests log file?

[Perryg]

Right click the guest in the main manager and then click show log. Save and post ( as an attachment )

[loukingjr]

Important notice regarding Mac OS X as Guest

[subtektor]

Right click the guest in the main manager and then click show log. Save and post ( as an attachment )

Ok I think I know what's going on here, the VM goes to sleep or something if I tab out of the Virtual machine.

[Perryg]

Still need the guest log file!

[subtektor]

Still need the guest log file!

Hmm I don't know what I happened, I did upload it :/
Ehh probably forgot to press "add file"

[Perryg]

VirtualBox VM 4.3.28 r100309 win.amd64 (May 13 2015 16:10:12) release log

Not allowed.