Demo scripts Virtuozzo
This article is for Virtuozzo 7 only.The following demo scripts (scenarios) can be used to show advantages of Virtuozzo.
Contents
Full container lifecycle
Create a container, set an IP, start, add a user, enter, exec, show
ps -axf output inside the container, stop, and destroy.
It should take about two minutes ("compare that to a time you need
to deploy a new (non-virtual) server!"). During the demonstration,
describe what's happening and why.
Here are the example commands needed:
# NAME=vz # IP=10.1.1.123/24 # sed -i "/$IP /d" ~/.ssh/ # time prlctl create $NAME --ostemplate centos-6-x86_64 --vmtype=ct # prlctl set $NAME --ipadd $IP --hostname $NAME # prlctl start $NAME # prlctl exec $NAME ps axf # prlctl set $NAME --userpasswd guest:secret # ssh guest@$IP [vz]# ps axf [vz]# logout # prlctl stop $NAME # prlctl destroy $NAME
Multiple containers creation
Create/start 10 containers in a shell loop.
Here are the example commands needed:
# time for ((CT=100; CT<110; CT++)); do \ time prlctl create $CT --ostemplate centos-6-x86_64 --vmtype=ct; \ prlctl start $CT; \ done
Massive container load
Use containers from the previous item — load those by ab or
http_load. This demo shows that multiple containers are working
just fine, with low response time etc.
# for ((CT=200; CT<250; CT++)); do \ prlctl set $CT --ipadd 10.1.1.$CT/24; \ done
On another machine:
# rpm -ihv http_load #
FIXME: http_load commands
Live migration
xscreensaver inside container
If you have two boxes, do vzmigrate --online from one box
to another. You can use, say, xvnc in a container and
vncclient to connect to it, then run
xscreensaver-demo, choose a suitable screensaver (eye-candy but
not too CPU aggressive) and while the picture is moving start a live
migration. You'll see that xscreensaver stalls for a few
seconds but then continues to run — on another machine! That looks amazing,
to say at least.
FIXME: commands, setup, VNC template.
CRIU (Checkpoint and Restore In Userspace)
- Simple loop
- Migration of Doom inside container inside LXC container
- Checkpoint and Restore of Docker container
- CRIU + tmux
This is a tech demo of CRIU and Docker integration, featuring tmux.
docker run -t -i --privileged --name critmux jpetazzo/critmux Do stuff in tmux. Don't know what to do? Just type a few characters. From another terminal, docker stop critmux. Container stops. docker start critmux ; docker attach critmux. MIND. BLOWN. Note: docker start -a doesn't quite work.
See screencast recorded with Asciinema.
P.Haul
Docker inside CT
Resource management
Below scenarios aims to show how OpenVZ resource management works.
UBC protection
fork() bomb
# while [ true ]; do \
while [ true ]; do \
echo " " > /dev/null;
done &
done
We can see that the number of processes inside container will not be growing.
We will see only the increase of numproc and/or
kmemsize fail counters in /proc/user_beancounters.
dentry cache eat up
FIXME
CPU scheduler
Create 3 containers:
# prlctl create 101 # prlctl create 102 # prlctl create 103
Set container weights:
# prlctl set 101 --cpuunits 1000 # prlctl set 102 --cpuunits 2000 # prlctl set 103 --cpuunits 3000
We set next CPU sharing CT101 : CT102 : CT103 = 1 : 2 : 3
Start containers:
# prlctl start 101 # prlctl start 102 # prlctl start 103
Run busy loops in all containers:
# prlctl enter 101 [ve101]# while [ true ]; do true; done # prlctl enter 102 [ve102]# while [ true ]; do true; done # prlctl enter 103 [ve103]# while [ true ]; do true; done
Check in top that sharing works:
# top COMMAND %CPU bash 48.0 bash 34.0 bash 17.5
So, we see that CPU time is given to container in proportion ~ 1 : 2 : 3.
Now start some more busy loops. CPU distribution should remain the same.
Disk quota
# prlctl set CTID --diskspace 1048576:1153434 --save # prlctl start CTID # prlctl enter CTID [ve]# dd if=/dev/zero of=/tmp/tmp.file bs=1048576 count=1000 dd: writing `/tmp/tmp.file': Disk quota exceeded