Hi, 

a few thoughts:
-analyze what exactly time is spent on using Nova logs 
(api+scheduler+conductor+compute)+Neutron (agent, bind port stuff)+Libvirt/QEMU 
logs. Use req-id and UUID of instance to identify the ’slow’ case across logs.
Take a look at the create instance’ flow that is present in bunch of websites 
in internet and make a draft of distribution of time for each stage
(side note: maybe there is tool that will allow such thing?). Turn on debug 
logging in Nova and Neutron to narrow it down in case necessary .
-compare CPU/RAM consumption in normal case and ‘slow’ case’

> How do I bound my vCPU all the way to the physical host?

Answer is CPU pinning. But yup, that is about CPU utilization on host , not 
related to time of VM launch.
Note that for general-purpose case CPU pinning can be an overkill in a way that 
general-purpose relies
on scheduling by host OS and it should not be problematic. And most 
configurations run with oversubscription of CPU 16 which is default (1 physical 
CPU=16 virtual)
'Specific purpose' cases are like NFV/Telco where CPU pinning is much-much more 
used.

BR, 
Konstantin


> On Dec 19, 2016, at 5:27 AM, Vikram Chhibber <[email protected]> 
> wrote:
> 
> Hi All,
> 
> I am using Kilo release 1:2015.1.4-0ubuntu2 for my lab deployment on single 
> physical host. The issue is that I am getting very low performance when I 
> launch multiple VM instances. The first one boots up within seconds but the 
> second takes noticeable time. If I instantiate the third instance when two 
> instances are already running, it may take 30 minutes to come up. Moreover, 
> the CPU idle % for a given instance keeps decreasing as number of running 
> instances increase.
> I am suspecting that this behavior is because be lack of bounding of vCPUs 
> with physical CPUs.
> Because of single node installation, the compute node itself becomes 
> virtualized and run my instances within it. How do I bound my vCPU all the 
> way to the physical host? I did not see any documentation regarding this for 
> Kilo release and there is no mention of bounding CPU for the virtualized 
> compute node on single node installation.
> 
> This is the specification of the host:
> Architecture:          x86_64
> CPU op-mode(s):        32-bit, 64-bita
> Byte Order:            Little Endian
> CPU(s):                36
> On-line CPU(s) list:   0-35
> Thread(s) per core:    2
> Core(s) per socket:    18
> Socket(s):             1
> NUMA node(s):          1
> Vendor ID:             GenuineIntel
> CPU family:            6
> Model:                 63
> Stepping:              2
> CPU MHz:               1200.000
> BogoMIPS:              4599.94
> Virtualization:        VT-x
> L1d cache:             32K
> L1i cache:             32K
> L2 cache:              256K
> L3 cache:              46080K
> NUMA node0 CPU(s):     0-35
> 
> 
> Spec. for the compute node:
> Architecture:          x86_64
> CPU op-mode(s):        32-bit, 64-bit
> Byte Order:            Little Endian
> CPU(s):                26
> On-line CPU(s) list:   0-25
> Thread(s) per core:    1
> Core(s) per socket:    1
> Socket(s):             26
> NUMA node(s):          1
> Vendor ID:             GenuineIntel
> CPU family:            6
> Model:                 6
> Stepping:              3
> CPU MHz:               2299.996
> BogoMIPS:              4599.99
> Virtualization:        VT-x
> Hypervisor vendor:     KVM
> Virtualization type:   full
> L1d cache:             32K
> L1i cache:             32K
> L2 cache:              4096K
> NUMA node0 CPU(s):     0-25
> 
> 
> Spec for my instance:
> Architecture:          x86_64
> CPU op-mode(s):        32-bit, 64-bit
> Byte Order:            Little Endian
> CPU(s):                4
> On-line CPU(s) list:   0-3
> Thread(s) per core:    1
> Core(s) per socket:    1
> Socket(s):             4
> NUMA node(s):          1
> Vendor ID:             GenuineIntel
> CPU family:            15
> Model:                 6
> Stepping:              1
> CPU MHz:               2299.994
> BogoMIPS:              4599.98
> Virtualization:        VT-x
> Hypervisor vendor:     KVM
> Virtualization type:   full
> L1d cache:             32K
> L1i cache:             32K
> L2 cache:              4096K
> NUMA node0 CPU(s):     0-3
> 
> Thanks
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