I'm sorry for giving you the wrong information. I didn't use the -drive parameter in QEMU, but the -blockdev parameter instead.
Below are the commands I used in the scenario where I/O performance remains the same 1-1 execute the qemu process with ... -object throttle-group,id=tg,x-bps-total=10485760 \ -blockdev '{"driver":"qcow2","node-name":"qcow2-node","file":{"driver":"file","filename":"/path/to/file.qcow2"}}' \ -device virtio-blk-pci,scsi=off,drive=qcow2-node,id=did,bootindex=1,bus=pci.0,addr=0x05,serial=1234 1-2 run the blockdev-add command via qmp socket { "execute":"blockdev-add", "arguments":{ "driver": "throttle", "node-name": "throttle-node", "throttle-group": "tg", "file": "qcow2-node" }} scenario where throttle works as expected 2-1 execute the qemu process with ... -object throttle-group,id=tg,x-bps-total=10485760 \ -blockdev '{"driver":"throttle","throttle-group":"tg","node-name":"throttle-node","file":{ "driver":"qcow2","node-name":"qcow2-node","file":{"driver":"file","filename":"/path/to/file.qcow2"} }}' \ -device virtio-blk-pci,scsi=off,drive=qcow2-node,id=did,bootindex=1,bus=pci.0,addr=0x05,serial=1234 2025년 1월 8일 (수) 오후 6:45, Henry lol <pub.virtualizat...@gmail.com>님이 작성: > > Hello, > > I want to apply a throttle block filter using the QMP command, but it > doesn't seem to work as the I/O performance remains the same. > > Are there any additional steps I need to follow? > I predefined the throttle-group object and block device in the QEMU > parameters and then used the blockdev-add QMP command to apply the > filter, as described in the link > - https://github.com/qemu/qemu/blob/master/docs/throttle.txt#L315-L322 > > Additionally, I’ve confirmed that the filter works well when defined > in the QEMU -drive parameter instead of using the QMP command. > > thanks,