Ideally there should be a warning if a user gives discard=unmap and isn't using the SCSI bus. Using the following options allows the guest to detect the drive as a thinly provisioned drive.
-drive discard=unmap,detect- zeroes=unmap,cache=none,file=vms/win10.hd.img.vmdk,format=vmdk,if=none,id=hd -device virtio-scsi-pci,id=scsi -device scsi-hd,drive=hd -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1523246 Title: Cannot TRIM with VirtIO Status in QEMU: New Bug description: When model=virtio is used, TRIM is not supported. # mount -o discard /dev/vda4 /mnt # mount | tail -1 /dev/vda4 on /mnt type fuseblk (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096) # fstrim /mnt/ fstrim: /mnt/: the discard operation is not supported Booting without model=virtio allows using TRIM (in Windows as well). Full QEMU line: qemu-system-x86_64 -enable-kvm -cpu host -bios /usr/share/ovmf/ovmf_x64.bin -smp 2 -m 7G -vga qxl -usbdevice tablet -net nic,model=virtio -net user -drive discard=unmap,detect- zeroes=unmap,cache=none,file=vms/win10.hd.img.vmdk,format=vmdk,if=virtio To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1523246/+subscriptions
