Hi Openstack-users, I am having a problem with I/O performance on VM running Oracle Linux 6, I/O throughput on VM Oracle Linux 6 is much lower than VM using another OS (Ubuntu, CentOS). - VM Oracle Linux 6: throughput 40 MBps https://prnt.sc/buKscX_qEtcF - Other VM: throughput 113 MBps https://prnt.sc/IRhBUPrGgLOy - Test tool: dd bs=1M count=1024 if=/dev/zero of=test conv=fdatasync; rm -f test My Enviroment: - Openstack: Ussuri - Ceph: Octopus 15.2.8 - Compute: CentOS8_x86_64, kernel: 4.18.0-240.15.1.el8_3.x86_64 - KVM: qemu-kvm-5.2.0-16.el8.x86_64 - VM Oracle linux6: kernel-uek-4.1.12-124.42.3.el6uek.x86_64 I think because the kernel of Oracle Linux 6 is too old, maybe an older KVM version could support it, and now KVM does not optimize for this OS. Could you guy can help me with this? -- *Lê Quang Long* 0942.533.683 | 0977.116.502