Hello. I followed the official documentation of Havana for Ubuntu 12.04, but I install OpenStack under VirtualBox. There are three VirtualBox ubuntu servers which are controller, compute1 and block1. Everything goes well but when I attach a cinder-volume to an active instance, the status of the volume first became "attaching", but after a while it became "available" again, and it didn't attach successfully.

There is an error in "/var/log/nova-compute" in compute1 :

1601 ERROR nova.virt.libvirt.driver [-] getting disk size of instance-00000005: [Error 2] No such file or directory 'var/lib/nova/instances/12345dgs-2434-sgg1-df44-adf7qe8qe7r8/disk'

And in "/var/log/syslog" in block1:

block 1 kernel: [    16.789114] lp : driver loaded but no devices found  

block 1 kernel: [    18.195309] EXT4-fs (sda1) : re-mounted. Opts: errors=remount-ro

By the way, I was wondering do I need to install iscsi initiator on compute1?

Does anyone know what should I do? Thanks a lot!