Hi, all. Please help with the problem ... ProxMox 5.3, when the disk is under high IO (backup, recovery or just dd), KVM machines become completely frozen (network, cpu). I read the links below, but these recipes did not help. I tried to use 4.13 kernel, but with no luck... Is there any solution to this problem? Local disks are used, no LVM, ext4 file system. bugzilla.kernel.org/show_bug.cgi?id=199727 bugzilla.proxmox.com/show_bug.cgi?id=1453 forum.proxmox.com/threads/kvm-guests-freeze-hung-tasks-during-backup-restore-migrate.34362/ forum.proxmox.com/threads/frequent-cpu-stalls-in-kvm-guests-during-high-io-on-host.30702/ (Sorry, I can't post likns ) Versions: Spoiler: Versions Code: # pveversion -v proxmox-ve: 5.3-1 (running kernel: 4.15.18-9-pve) pve-manager: 5.3-5 (running version: 5.3-5/97ae681d) pve-kernel-4.15: 5.2-12 pve-kernel-4.13: 5.2-2 pve-kernel-4.15.18-9-pve: 4.15.18-30 pve-kernel-4.15.18-1-pve: 4.15.18-19 pve-kernel-4.13.16-4-pve: 4.13.16-51 pve-kernel-4.13.13-6-pve: 4.13.13-42 pve-kernel-4.4.44-1-pve: 4.4.44-84 pve-kernel-4.4.10-1-pve: 4.4.10-54 pve-kernel-4.4.8-1-pve: 4.4.8-52 corosync: 2.4.4-pve1 criu: 2.11.1-1~bpo90 glusterfs-client: 3.8.8-1 ksm-control-daemon: 1.2-2 libjs-extjs: 6.0.1-2 libpve-access-control: 5.1-3 libpve-apiclient-perl: 2.0-5 libpve-common-perl: 5.0-43 libpve-guest-common-perl: 2.0-18 libpve-http-server-perl: 2.0-11 libpve-storage-perl: 5.0-33 libqb0: 1.0.3-1~bpo9 lvm2: 2.02.168-pve6 lxc-pve: 3.0.2+pve1-5 lxcfs: 3.0.2-2 novnc-pve: 1.0.0-2 openvswitch-switch: 2.7.0-3 proxmox-widget-toolkit: 1.0-22 pve-cluster: 5.0-31 pve-container: 2.0-31 pve-docs: 5.3-1 pve-edk2-firmware: 1.20181023-1 pve-firewall: 3.0-16 pve-firmware: 2.0-6 pve-ha-manager: 2.0-5 pve-i18n: 1.0-9 pve-libspice-server1: 0.14.1-1 pve-qemu-kvm: 2.12.1-1 pve-xtermjs: 1.0-5 qemu-server: 5.0-43 smartmontools: 6.5+svn4324-1 spiceterm: 3.0-5 vncterm: 1.5-3