We find our VM boot at first time isreally very slow. When we boot a VM with 1.4GB image , we need about 5 mins.

The resean is nova need to download theimage through Glance. And store the image into /var/lib/nova/instance/_base .

The transmit of the image cost about 5 mins.And I find when we use swift download the image on the compute, we just needabout 0.5mins.

And if we download the image through glancewe need 5 mins.

Swift download data flow: (performance isGood)

Client(On compute1)  à HA(8080)  à  Swift proxy(8080) à Swift Storage

# date; swift download glance8966460a-9dba-4a56-b208-a20b29f8d6f4 ; date

Tue Oct 29 08:20:36 GMT 2013

8966460a-9dba-4a56-b208-a20b29f8d6f4[headers 0.286s, total 28.637s, 50.915s MB/s]

Tue Oct 29 08:21:05 GMT 2013

Glance download data flow: (performance isBad)

Client(On compute1)  à HA(9292)  à  Glance api(9292)  à HA (8080) à Swiftproxy(8080) à Swift Storage

# date; glance image-download8966460a-9dba-4a56-b208-a20b29f8d6f4 > test.img ; date

Tue Oct 29 08:04:56 GMT 2013

Tue Oct 29 08:10:00 GMT 2013

This means the swift is not the bottleneckwhile download the image.

We find that if client communite withglance without haproxy, the performance will be good.

Client(On compute1)  à  Glanceapi(9292)  à HA (8080) à Swift proxy(8080) à Swift Storage

# date; glance image-download8966460a-9dba-4a56-b208-a20b29f8d6f4 > test.img ; date

Thu Oct 31 06:52:56 GMT 2013

Thu Oct 31 06:53:17 GMT 2013