Public bug reported: == Comment: #0 - I-HSIN CHUNG <ihch...@us.ibm.com> - 2019-11-15 12:35:05 == ---Problem Description--- Ubuntu 18.04 - vm disk i/o performance issue when using file system passthrough Contact Information = ihch...@us.ibm.com ---uname output--- Linux css-host-22 4.15.0-1039-ibm-gt #41-Ubuntu SMP Wed Oct 2 10:52:25 UTC 2019 ppc64le ppc64le ppc64le GNU/Linux (host) Linux ubuntu 4.15.0-65-generic #74-Ubuntu SMP Tue Sep 17 17:08:54 UTC 2019 ppc64le ppc64le ppc64le GNU/Linux (vm) Machine Type = p9/ac922 ---Debugger--- A debugger is not configured ---Steps to Reproduce--- 1. Env: Ubuntu 18.04.3 LTS?Genesis kernel linux-ibm-gt - 4.15.0-1039.41?qemu 1:2.11+dfsg-1ubuntu7.18 ibmcloud0.3 or 1:2.11+dfsg-1ubuntu7.19 ibm-cloud1?fio-3.15-4-g029b
2. execute run.sh to run fio benchmark: 2.1) run.sh: #!/bin/bash for bs in 4k 16m do for rwmixread in 0 25 50 75 100 do for numjobs in 1 4 16 64 do echo ./fio j1.txt --bs=$bs --rwmixread=$rwmixread --numjobs=$numjobs ./fio j1.txt --bs=$bs --rwmixread=$rwmixread --numjobs=$numjobs done done done 2.2) j1.txt: [global] direct=1 rw=randrw refill_buffers norandommap randrepeat=0 ioengine=libaio iodepth=64 runtime=60 allow_mounted_write=1 [job2] new_group filename=/dev/vdb filesize=1000g cpus_allowed=0-63 numa_cpu_nodes=0 numa_mem_policy=bind:0 3. performance profile: device passthrough performance for the nvme: http://css-host-22.watson.ibm.com/rundir/nvme_vm_perf_vm/20191011-112156/html/#/measurement/vm/ubuntu (I/O bandwidth achieved inside VM in GB/s range) file system passthrough http://css-host-22.watson.ibm.com/rundir/nvme_vm_perf_vm/20191106-123613/html/#/measurement/vm/ubuntu (I/o bandwidth achieved inside the VM is very low) desired performance when using file system passthrough should be similar to the device passthrough Userspace tool common name: fio The userspace tool has the following bit modes: should be 64 bit Userspace rpm: ? Userspace tool obtained from project website: na *Additional Instructions for ihch...@us.ibm.com: -Post a private note with access information to the machine that the bug is occuring on. -Attach ltrace and strace of userspace application. ** Affects: qemu (Ubuntu) Importance: Undecided Assignee: Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) Status: New ** Tags: architecture-ppc64le bugnameltc-182496 severity-medium targetmilestone-inin18045 ** Tags added: architecture-ppc64le bugnameltc-182496 severity-medium targetmilestone-inin18045 ** Changed in: ubuntu Assignee: (unassigned) => Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) ** Package changed: ubuntu => qemu (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1853042 Title: Ubuntu 18.04 - vm disk i/o performance issue when using file system passthrough To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1853042/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
