one of 20 kvm vm does not start reliably


Active Member
Aug 6, 2019
Hi support team,

we are running several kvm vm's on a cluster of two nodes. We have one vm that does not start reliably.
Often the start via commandline (script) "qm start " ends with an:

TASK ERROR: start failed: command '/usr/bin/kvm -id 200 -name xen5-bkup -chardev 'socket,id=qmp,path=/var/run/qemu-server/200.qmp,server,nowait' -mon 'chardev=qmp,mode=control' -chardev 'socket,id=qmp-event,path=/var/run/qmeventd.sock,reconnect=5' -mon 'chardev=qmp-event,mode=control' -pidfile /var/run/qemu-server/ -daemonize -smbios 'type=1,uuid=270034e8-e942-47ca-a03b-2ff765dae193' -smp '8,sockets=2,cores=4,maxcpus=8' -nodefaults -boot 'menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg' -vnc unix:/var/run/qemu-server/200.vnc,password -cpu kvm64,+lahf_lm,+sep,+kvm_pv_unhalt,+kvm_pv_eoi,enforce -m 81920 -device 'pci-bridge,id=pci.1,chassis_nr=1,bus=pci.0,addr=0x1e' -device 'pci-bridge,id=pci.2,chassis_nr=2,bus=pci.0,addr=0x1f' -device 'vmgenid,guid=9e96020f-b4c7-4180-8258-61131d28557d' -device 'piix3-usb-uhci,id=uhci,bus=pci.0,addr=0x1.0x2' -device 'usb-tablet,id=tablet,bus=uhci.0,port=1' -device 'vfio-pci,host=0000:85:00.0,id=hostpci1,bus=pci.0,addr=0x11' -device 'VGA,id=vga,bus=pci.0,addr=0x2' -chardev 'socket,path=/var/run/qemu-server/200.qga,server,nowait,id=qga0' -device 'virtio-serial,id=qga0,bus=pci.0,addr=0x8' -device 'virtserialport,chardev=qga0,name=org.qemu.guest_agent.0' -iscsi '' -drive 'if=none,id=drive-ide1,media=cdrom,aio=threads' -device 'ide-cd,bus=ide.0,unit=1,drive=drive-ide1,id=ide1,bootindex=200' -device 'virtio-scsi-pci,id=scsihw0,bus=pci.0,addr=0x5' -drive 'file=/mnt/vmstore/images/200/vm-200-disk-0.qcow2,if=none,id=drive-scsi0,discard=on,format=qcow2,cache=none,aio=native,detect-zeroes=unmap' -device 'scsi-hd,bus=scsihw0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0,id=scsi0,bootindex=100' -netdev 'type=tap,id=net0,ifname=tap200i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on' -device 'virtio-net-pci,mac=EE:C8:CB:05:02:72,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300' -machine 'type=pc+pve1'' failed: got timeout


Linux 5.0.21-5-pve #1 SMP PVE 5.0.21-10 (Wed, 13 Nov 2019 08:27:10 +0100)

PVE Manager Version


Starting it from the WEB UI mostly works.

The difference between this and the other vm's is that the vm has much more ram assigned (80GB) and has one pci card (Emulex) passed through.

Any idea on how to proceed and find out more about this issue ?

Last edited:
There is more than 300 GB Mem free (machine has 512 GB). I will give the setting a try and come back.
Thanks for your hint.
OK I tested a bit. I need to set:

qm set 200 --hugepages 2
qm set 200 --numa 1

then the vm starts each time (20 attemps, all successfull).

So can you please explain a bit more what is the root cause and what does hugepages 2 mean ?



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