Hi, when I tried to set up an Arch Linux guest on an external USB HDD, something strange happened. VM memory size is: 512 MB VDIs are: /mnt/archvm/archvm_sda.vdi /mnt/archvm/archvm_sdb.vdi Snapshot folder: /mnt/archvm/archvm_snap After creating this I made a snapshot named "Empty partitions". I inserted a Grml 2014.11 Linux DVD for partitioning and started the VM. It booted from the DVD, but after a while there was a black screen. I powerd off the machine, got a non-fatal error, ignored the error's details, because I anyway wanted to restore the snapshot, instead of fixing the current state. If I try to restore the snapshot, I get the below error. I can't find information about it in the Internet. Failed to restore the snapshot Empty partitions of the virtual machine archVM. Could not create the differencing medium storage unit '/mnt/archvm/archvm_snap/{834e9194-84b5-443a-a5e1-8bf9bb28855d}.vdi'. VDI: cannot create image '/mnt/archvm/archvm_snap/{834e9194-84b5-443a-a5e1-8bf9bb28855d}.vdi' (VERR_DEV_IO_ERROR). Result Code: VBOX_E_FILE_ERROR (0x80BB0004) Component: Medium Interface: IMedium {05f2bbb6-a3a6-4fb9-9b49-6d0dda7142ac} [rocketmouse@archlinux ~]$ pacman -Q virtualbox virtualbox 4.3.12-1 [rocketmouse@archlinux ~]$ uname -r 3.10.61-rt65-1-rt-lts Yes, all vbox packages are in the IgnorePkg list, since no version > 4.3.12 can be used with a XP guest and an iPad2 connected by USB, when updating iOS. DKMS doesn't build the old modules for the current kernel, so I need to run older kernels. 1. Does anybody know what's going wrong, when I try to restore the snapshot? And how can I solve this? 2. Is there another virtual machine easy to use, without a huge learning curve? Any recommendations? I want to simulate my real Arch Linux install, copied from a backup of the host, to the guest, to test steps, to fix a few issues with my real (host) install, but I don't need to stay with vbox for that purpose. Regards, Ralf