Error using VM flavors with certain network quota parameters

Solution In Progress - Updated -


  • We are having issue creating VMs using a most of our VM flavors after upgrading to OSP 16.2. These flavor parameters have worked for us in previous OSP versions (16.0 and 16.1)

  • When creating a VM using certain VM flavors, the VM creation fails and nova-conductor logs show a following error related to "tc" command.

'libvirt.libvirtError: internal error: Child process (tc class add dev tap07a2bdfd-a5 parent 1: classid 1:1 htb rate 10000kbps ceil 50000kbps burst 15000000kb quantum 853) unexpected exit status 1: Illegal "buffer"\nUsage: ... qdisc add ... htb [default N] [r2q N]\n 
  • An example of a flavor quotas that previously worked but no longer does:

we found a workaround that if we remove "vif_inbound_average" and "vif_outbound_average" settings, the rest of the settings apply and VM builds.

  • Also for comparison, following set of quota settings continued to work post upgrade:
quota:vif_inbound_average: 2500
quota:vif_inbound_burst: 3750000
quota:vif_inbound_peak: 12500
quota:vif_outbound_average: 2500
quota:vif_outbound_burst: 3750000
quota:vif_outbound_peak: 12500


  • Red Hat OpenStack Platform 16.2 (RHOSP)

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