I am using Qemu's block-dirty-bitmap features to perform full/incremental backups of my qcow2 images. Things are working great but when I go to perform the initial full backup command to create the bitmap I get "libvirt-49 Could not create file: Permission denied". I'm issuing these json-based commands to the qemu monitor via the virsh qemu-monitor-command command. Yes, the dest. dir is owned by libvirt-qemu.kvm user/group.
The only time I get this permission error is when I'm trying to write backup qcow2 files to a dynamically-mounted external drive (USB, etc.). If I create a manual mount point for it and provide an entry in my fstab file, things work great. Any idea how I can do backups to destination disks that are auto-mounted (mounted automatically when I plug-in the external USB disk? The command I'm running is: virsh qemu-monitor-command ubuntu16.04 --pretty \ '{"execute": "transaction",' \ ' "arguments":' \ ' {' \ ' "actions":' \ ' [' \ ' {"type": "block-dirty-bitmap-add",' \ ' "data": {"node": "drive-virtio-disk1", "name": "bitmap0"}' \ ' },' \ ' {"type": "drive-backup",' \ ' "data": {"device": "drive-virtio-disk1",' \ ' "target": "/media/mike/Seagate2TB/backups/qemu/ubuntu16.04/2014-09-24/ubuntu16.04_full_backup_2017-09-24.qcow2",' \ ' "sync": "full", "format": "qcow2"' \ ' }' \ ' }' \ ' ]' \ ' }' \ '}' Thanks. Mike