Hi Nick, Try running "ls -l /rhev/data-center/00000001-0001-0001-0001-00000000037d/88dfff37-4ad5-446c-a957-1cf67829c9a6/images/da93350c-8926-42bf-99fa-8a7aca043fcd/22e7803d-e266-4e3e-ae34-0181f8acef8b" and check the ownership of the file. It should be owned by vdsm:kvm (or user and group 36:36 I think) Another thing to check would be that the parent directories are accessible. Try running "sudo -s /bin/bash vdsm" and then "cd /rhev/data-center/00000001-0001-0001-0001-00000000037d/88dfff37-4ad5-446c-a957-1cf67829c9a6/images" to make sure you can access all the parent folders. If you can, try creating a temp file ("echo hello >hello") in that same directory to make sure that the iSCSI mount hasn't gone read only. If none of that helps, I'd say take a look at the output of vgdisplay to make sure that the volume group still has free physical extents (Free PE/Size near the bottom) If you are using thin provisioning that might be an issue. This is all based on the issue being disk permission errors. It might be an error with the libvirt authentication, but I have no idea how to diagnose that. On 16-04-18 05:32 AM, users-request(a)ovirt.org wrote: Message: 2 Date: Mon, 18 Apr 2016 10:32:40 +0200 From: &quot;nicola.gentile.to&quot;&lt;nicola.gentile.to(a)gmail.com&gt; To:Users@ovirt.org Subject: [ovirt-users] any virtual machine does not start Message-ID:<57149BA8.90803@gmail.com> Content-Type: text/plain; charset="iso-8859-15"; Format="flowed" hi, I have a problem with ovirt 3.6. When I click on the button "run" to start vm, it not start and terminate immediatly. This is the error in the admin portale: VM ubuexp is down with error. Exit message: internal error: process exited while connecting to monitor: 2016-04-18T08:18:22.499782Z qemu-kvm: -drive file=/rhev/data-center/00000001-0001-0001-0001-00000000037d/88dfff37-4ad5-446c-a957-1cf67829c9a6/images/da93350c-8926-42bf-99fa-8a7aca043fcd/22e7803d-e266-4e3e-ae34-0181f8acef8b,if=none,id=drive-virtio-disk0,format=qcow2,serial=da93350c-8926-42bf-99fa-8a7aca043fcd,cache=none,werror=stop,rerror=stop,aio=native: Could not open '/rhev/data-center/00000001-0001-0001-0001-00000000037d/88dfff37-4ad5-446c-a957-1cf67829c9a6/images/da93350c-8926-42bf-99fa-8a7aca043fcd/22e7803d-e266-4e3e-ae34-0181f8acef8b': Permission denied . My ovirt installation is composed of thefollowing: - 1 manager (virtualized) - 1 host - storage iscsi Everything seems to work well from the web administration portal, but all vm do not start. I attach a log file. Please help me! Nick