Thank you for the quick reply. - I/O scheduler hosts -> changed echo noop > /sys/block/sdb/queue/scheduler echo noop > /sys/block/sdc/queue/scheduler - CPU states -> can you explain this a bit more? cat /dev/cpu_dma_latency F hexdump -C /dev/cpu_dma_latency 00000000 46 00 00 00 |F...| 00000004 - Tuned profile -> can you explain this a bit more? - MTU was already set to 9000 -> can you explain a bit more tcp-offloading and how I change the settings? ethtool -k enp1s0f0 | grep offload tcp-segmentation-offload: on udp-fragmentation-offload: off [fixed] generic-segmentation-offload: on generic-receive-offload: on large-receive-offload: off [fixed] rx-vlan-offload: on tx-vlan-offload: on l2-fwd-offload: off [fixed] hw-tc-offload: off rx-udp_tunnel-port-offload: on - I/O scheduler VM had already none cat /sys/block/vda/queue/scheduler none - oVirt 4.4 -> thanks. Was not aware that the new version is final. I will check and upgrade. - Use High Performance VMs -> I got following message -> So I need to do changes also on the VM? The following recommended settings for running the High Performance type with the optimal configuration were not detected. Please consider manually changing of the following before applying: CPU PINNING: VIRTUAL NUMA AND NUMA PINNING: HUGE PAGES: KERNEL SAME PAGE MERGING (KSM): - libgfapi -> I will execute on the engine following command and then it will change all VMs after reboot? engine-config -s LibgfApiSupported=true --cver4.2 - changed values (from your other threat): gluster volume set vmstore performance.read-ahead on gluster volume set vmstore performance.stat-prefetch on gluster volume set vmstore performance.write-behind-window-size 64MB gluster volume set vmstore performance.flush-behind on - already configured: performance.client-io-threads: on Best Regards Dirk