Qemu virtio disk performance unmap, write same, SCSI pass-through) • virtio-blk DISCARD and WRITE ZEROES are being worked on • Use virtio-blk for best performance virtio-blk, iodepth=1, randread virtio-scsi, iodepth=1, randread vitio-blk, iodepth=4, randread virtio-scsi, iodepth=4, randread See full list on pve. 0, we observed substantial gains in storage performance and scalability. g. In that case it is recommended to use “iothread“. . Whether raw or qcow2 image files, you will want to use the virtio driver. Inside the VM start script, modify the qemu-system-x86_64 command to include: First add a second virtio-scsi disk to your VM (like 1GB big, it's just temporary), then boot Windows. proxmox. Since there is a virtio-scsi controller attached, it will now allow you to install the virtio-scsi driver from the virtio driver ISO or by downloading it: • Use virtio-scsi for many disks, or for full SCSI support (e. Dec 4, 2018 · You may see some small performance gain when preallocating (full) disk space with qcow2 images, but this defeats thin provisioning. Specifically, by assigning multiple dedicated I/O threads to virtio, disk performance becomes markedly efficient and scalable, and of course, can be applied to more mount points and additional VMs. com Aug 1, 2023 · Hi folks If you are using KVM/QEMU as a host for Windows Guests - you can improve the disk performance in some cases significantly by instead of opting for the standard AHCI SATA built in driver -- sel to Virtio and the cache to writeback as per : You can get the Virtio ISO for Windows Mar 30, 2025 · Leveraging the new I/OThread Virtqueue Mapping feature from QEMU 9. tsjzuauipnfyxqwiqtymblgifevsrlezqaxivnpdcdcfvsgb