Been trying to figure out why my nvme ssd has high latency when writing. Latency can go up to +100ms once the write speed gets to around 15MB/s. Read isn't being impacted at all. I originally just had a vdisk on the drive. Then I tried passing through the drive, and then passed through the controller. All of these instances are seeing this high write latency issue. After re-installing windows on the drive after passing it through the drive, I booted the entire system from there, so not through unraid, and the issue isn't there. I've tried multiple different VM settings and have yet to find anything that's resolved this issue. I would absolutely love if somebody here has some idea to try to resolve this. Thanks.
 

 

Here's the VM's settings

Quote

<?xml version='1.0' encoding='UTF-8'?>
<domain type='kvm'>
  <name>Windows</name>
  <uuid>834bdc43-c3f7-d0f2-4783-e5d0ebe6b87a</uuid>
  <metadata>
    <vmtemplate xmlns="unraid" name="Windows 10" icon="windows.png" os="windows10"/>
  </metadata>
  <memory unit='KiB'>16777216</memory>
  <currentMemory unit='KiB'>16777216</currentMemory>
  <memoryBacking>
    <nosharepages/>
  </memoryBacking>
  <vcpu placement='static'>17</vcpu>
  <cputune>
    <vcpupin vcpu='0' cpuset='0'/>
    <vcpupin vcpu='1' cpuset='8'/>
    <vcpupin vcpu='2' cpuset='24'/>
    <vcpupin vcpu='3' cpuset='9'/>
    <vcpupin vcpu='4' cpuset='25'/>
    <vcpupin vcpu='5' cpuset='10'/>
    <vcpupin vcpu='6' cpuset='26'/>
    <vcpupin vcpu='7' cpuset='11'/>
    <vcpupin vcpu='8' cpuset='27'/>
    <vcpupin vcpu='9' cpuset='12'/>
    <vcpupin vcpu='10' cpuset='28'/>
    <vcpupin vcpu='11' cpuset='13'/>
    <vcpupin vcpu='12' cpuset='29'/>
    <vcpupin vcpu='13' cpuset='14'/>
    <vcpupin vcpu='14' cpuset='30'/>
    <vcpupin vcpu='15' cpuset='15'/>
    <vcpupin vcpu='16' cpuset='31'/>
  </cputune>
  <os>
    <type arch='x86_64' machine='pc-i440fx-5.1'>hvm</type>
    <loader readonly='yes' type='pflash'>/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi.fd</loader>
    <nvram>/etc/libvirt/qemu/nvram/834bdc43-c3f7-d0f2-4783-e5d0ebe6b87a_VARS-pure-efi.fd</nvram>
  </os>
  <features>
    <acpi/>
    <apic/>
  </features>
  <cpu mode='host-passthrough' check='none' migratable='on'>
    <topology sockets='1' dies='1' cores='17' threads='1'/>
    <cache mode='passthrough'/>
    <feature policy='require' name='topoext'/>
  </cpu>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
    <timer name='pit' tickpolicy='delay'/>
    <timer name='hpet' present='no'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/local/sbin/qemu</emulator>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/mnt/user/isos/Windows10.iso'/>
      <target dev='hda' bus='sata'/>
      <readonly/>
      <boot order='2'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/mnt/user/isos/virtio-win-0.1.190-1.iso'/>
      <target dev='hdb' bus='sata'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
    </disk>
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='writeback'/>
      <source dev='/dev/disk/by-id/nvme-INTEL_SSDPEKNW010T9_BTNR013323RC1P0B'/>
      <target dev='hdc' bus='sata'/>
      <boot order='1'/>
      <address type='drive' controller='0' bus='0' target='0' unit='2'/>
    </disk>
    <controller type='usb' index='0' model='qemu-xhci' ports='15'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
    </controller>
    <controller type='sata' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </controller>
    <controller type='pci' index='0' model='pci-root'/>
    <interface type='bridge'>
      <mac address='52:54:00:3f:af:a2'/>
      <source bridge='virbr1'/>
      <model type='virtio-net'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target type='isa-serial' port='0'>
        <model name='isa-serial'/>
      </target>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
    <channel type='unix'>
      <target type='virtio' name='org.qemu.guest_agent.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='1'/>
    </channel>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x0a' slot='0x00' function='0x0'/>
      </source>
      <rom file='/mnt/disk1/isos/EditedGA104.rom'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x0a' slot='0x00' function='0x1'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x05' slot='0x00' function='0x0'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </hostdev>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x0c45'/>
        <product id='0x5004'/>
      </source>
      <address type='usb' bus='0' port='1'/>
    </hostdev>
    <memballoon model='none'/>
  </devices>
</domain>

 

 

 

tower-diagnostics-20210928-1306.zip

tower-smart-20210928-1117.zip

Edited September 28, 20214 yr by solidsolid
uploaded smart report for drive

1 hour ago, solidsolid said:

    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='writeback'/>
      <source dev='/dev/disk/by-id/nvme-INTEL_SSDPEKNW010T9_BTNR013323RC1P0B'/>
      <target dev='hdc' bus='sata'/>
      <boot order='1'/>
      <address type='drive' controller='0' bus='0' target='0' unit='2'/>
    </disk>

If this is VM SSD, you aren't passthrough it.

7 hours ago, Vr2Io said:

If this is VM SSD, you aren't passthrough it.

yea, sorry, these are settings after i already reverted the changes. I have tried passing through the entire controller for the nvme. unless im not seeing something here.