Public bug reported: This issue is introduced in QEMU 4.2.0 (4.1.0 is working fine)
My root disk is a LVM2 volume thin snapshot that is marked as read-only But when I try to start the domain (using virt-manager) I get the following error: Error starting domain: internal error: process exited while connecting to monitor: 2020-04-26T06:55:06.342700Z qemu-system-x86_64: -blockdev {"driver":"host_device","filename":"/dev/vg/vmroot-20200425","aio":"native ","node-name":"libvirt-3-storage","cache":{"direct":true,"no- flush":false},"auto-read-only":true,"discard":"unmap"} The device is not writable: Permission denied Changing the lvm snapshot to writeable allows me to start the domain. (Making it changes possible during domain is running) I don't think QEMU should fail when it can't open a (block) device when the read-only option is set. (why is write access needed?) Reproduce steps: * Create LVM read-only volume (I don't think any data is needed) * Create domain with read-only volume as block device * Try to start the domain ** Affects: qemu Importance: Undecided Status: New -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1875139 Title: Domain fails to start when 'readonly' device not writable Status in QEMU: New Bug description: This issue is introduced in QEMU 4.2.0 (4.1.0 is working fine) My root disk is a LVM2 volume thin snapshot that is marked as read-only But when I try to start the domain (using virt-manager) I get the following error: Error starting domain: internal error: process exited while connecting to monitor: 2020-04-26T06:55:06.342700Z qemu-system-x86_64: -blockdev {"driver":"host_device","filename":"/dev/vg/vmroot-20200425","aio":"native ","node-name":"libvirt-3-storage","cache":{"direct":true,"no- flush":false},"auto-read-only":true,"discard":"unmap"} The device is not writable: Permission denied Changing the lvm snapshot to writeable allows me to start the domain. (Making it changes possible during domain is running) I don't think QEMU should fail when it can't open a (block) device when the read-only option is set. (why is write access needed?) Reproduce steps: * Create LVM read-only volume (I don't think any data is needed) * Create domain with read-only volume as block device * Try to start the domain To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1875139/+subscriptions