This is a legacy behavior in QEMU. There are a number of legitimate use cases where a user may only have read access to an image and as long as that image is mounted read-only, everything will work okay.
Virtio and SCSI will expose the read-only attribute to the guest so it should be very obvious what's happening. Unfortunately, IDE does not support the concept of read-only. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/658610 Title: Check whether images have write permissions Status in QEMU: New Status in “qemu-kvm” package in Ubuntu: Confirmed Bug description: KVM/Qemu should check whether the disk images have write permissions in order to prevent users from getting weird IO errors in their VMs without understanding what's happening.
