How to disable output to console after launching QEMU VM?

Grafana Alert

6/23/23, 1:46 PM

I have to run three VMs on QEMU.

for VM in ctrl-vm src-vm dst-vm
do
    case ${VM} in
        "ctrl-vm")
            mac_addr=00:00:00:00:00:01
            tap=tap0
            port=30020
            ;;
        "src-vm")
            mac_addr=00:00:00:00:00:02
            tap=tap1
            port=30021
            ;;  
        "dst-vm")
            mac_addr=00:00:00:00:00:03
            tap=tap2
            port=30022
            ;;
    esac
    
    DISTRO="debian-bullseye"
    IMAGE_NAME=${VM}
    MACHINE_NAME="qemuamd64"
    IMAGE_TYPE="wic.img"
    ROOTFS="/dev/sda2"

    FULL_IMAGE_NAME="${IMAGE_NAME}-${DISTRO}-${MACHINE_NAME}"
    ISAR_OUT_DIR="${KAS_WORK_DIR}/build/tmp/deploy/images/${MACHINE_NAME}"
    DISK_PATH="${ISAR_OUT_DIR}/${FULL_IMAGE_NAME}"
    KERNEL="${DISK_PATH}-vmlinuz"
    INITRD="${DISK_PATH}-initrd.img"

    if [ -n "${QEMU_PATH}" ]; then
        QEMU_PATH="${QEMU_PATH}/"
    fi

    QEMU=qemu-system-x86_64
    QEMU_EXTRA_ARGS=" \
        -s \
        -nographic \
        -cpu host -smp 4 \
        -enable-kvm -machine q35 \
        -device ide-hd,drive=disk \
        -device virtio-net-pci,netdev=vnet0,mac=${mac_addr}" 
    KERNEL_CMDLINE=" \
        root=${ROOTFS} console=ttyS0 debug \
        "
    ${QEMU_PATH}${QEMU} \
        -drive file=${DISK_PATH}.${IMAGE_TYPE},discard=unmap,if=none,id=disk,format=raw \
        -m 1G \
        -netdev tap,id=vnet0,ifname=${tap},script=no,downscript=no \
        -net user,hostfwd=tcp::30020-:22 \
        -kernel "${KERNEL}" \
        -append "${KERNEL_CMDLINE}" \
        -initrd "${INITRD}" ${QEMU_EXTRA_ARGS} "$@" &

done

I would like to run VMs in the background and connect them via ssh (IPs are already assigned in the image). But when I run the script, the VM console starts in the same terminal, and the other 2 VMs do not start. I already added "&" at the end of the command, but still does not work.

0 + 0

qemu

Grafana Alert

6/23/23, 3:00 PM

Found the answer: I should use -daemonize.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: How to disable output to console after launching QEMU VM?

TH: จะปิดใช้งานเอาต์พุตไปยังคอนโซลหลังจากเรียกใช้ QEMU VM ได้อย่างไร

RO: Cum să dezactivez ieșirea către consolă după lansarea QEMU VM?

RU: Как отключить вывод на консоль после запуска QEMU VM?

VI: Làm cách nào để tắt đầu ra ra bàn điều khiển sau khi khởi chạy QEMU VM?

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