After I "send a shutdown signal", I find I have to reinstall Ubuntu Server inside VirtualBox. This doesn't seem right. I should simply have to restart an installed version of Ubuntu Server.
What am I doing wrong?
Edit: Sorry for not being explicit enough. I have a Mac OS X host, with Ubuntu Server in a VirtualBox guest. When I close the Ubuntu Server guest, I get the usual 3 options: "Save State", "Send Shutdown Signal", "Power Off Machine." I thought if I did "Send Shutdown Signal", my guest OS would shut down, and I would be able to easily restart it in future. Instead, the next time I try to revive my guest OS, I find I have to reinstall the entire damn thing. What am I doing wrong?