Ediv-tutorial
EDIV Tutorial: deploying virtual scenarios over VNX clusters
The use of EDIV tool to manage distributed virtual scenarios is very similar to VNX. The most common options used, for example, to start (-t), stop (-d or -P) or execute commands (-x) are the same in both tools. This document will show how to start the example tutorial_ubuntu-dynamips.xml over a cluster made of two hosts (host1 and host2); you can experiment with any other example (use tutorial_ubuntu.xml in case you do not have CISCO images for dynamips routers).
Before starting a virtual scenario, you can check how the distribution will be done using "--seg-info" option. For example:
# cd /usr/share/vnx/examples
# ediv -f tutorial_ubuntu-dynamips.xml --seg-info
...some stuff deleted...
---- mode: seg-info
---- Showing vm's to host mapping for tutorial_ubuntu-dynamips.xml
VM name Type Host
-------------------------------------------------------
h1 libvirt-kvm-linux host1
r2 dynamips-3600 host2
h3 libvirt-kvm-linux host1
h4 libvirt-kvm-linux host2
h2 libvirt-kvm-linux host2
r1 dynamips-3600 host1
In this case we are using the simple round robin segmentation algorithm, so the virtual machines are equally distributed over the two hosts.
You can show the segmentation algorithms available with using "--seg-alg-info" option:
# ediv --seg-alg-info
...some stuff deleted...
---- mode: seg-alg-info
---- Showing segmentation algorithms available
Algorithm name --> Filename
--------------------------------------------------------------------------------
RoundRobin --> /usr/share/vnx/lib/seg-alg/round_robin.pm
DynamicWeightedRoundRobin --> /usr/share/vnx/lib/seg-alg/dynamic_weighted_round_robin.pm
WeightedRoundRobin --> /usr/share/vnx/lib/seg-alg/weighted_round_robin.pm
And test the distribution with another algorithm specifiying it with "-a" option:
# ediv -f tutorial_ubuntu-dynamips.xml --seg-info -a WeightedRoundRobin
...some stuff deleted...
---- mode: seg-info
---- Showing vm's to host mapping for tutorial_ubuntu-dynamips.xml
VM name Type Host
-------------------------------------------------------
h1 libvirt-kvm-linux pasito
r2 dynamips-3600 pasito
h3 libvirt-kvm-linux chopito
h4 libvirt-kvm-linux chopito
h2 libvirt-kvm-linux pasito
r1 dynamips-3600 pasito
Before starting the scenario (as the error management of the tool is not well tuned yet) it is recommended to control each host log traces. To do that, in the controller just open one terminal window for each host and execute:
tail -f /var/log/vnx/<host_name>.log
changing <host_name> by the name of each cluster host.
Besides, it is also recomended to start the "ediv_monitor" simple tool that shows the scenarios and virtual machines deployed in each host:
ediv_monitor 2
To start the scenario just type:
ediv -f tutorial_ubuntu-dynamips.xml -t
If everything goes well, you will see the consoles of the six virtual machines being opened and the following tables at the end of command execution:
Scenario: tutorial_ubuntu-dynamips Date: mar may 29 23:35:12 CEST 2012 VM name Host Status ---------------------------------------------------------------------- h1 host1 running h2 host2 running h3 host1 running h4 host2 running r1 host1 running r2 host2 running ---------------------------------------------------------------------- -- Creating tunnels to access VM management interfaces -- -- To access VM at Host use command -- --------------------------------------------------------------- -- h1 host1 ssh root@localhost -p 64000 -- h2 host2 ssh root@localhost -p 64001 -- r1 host1 telnet localhost 64002 -- r2 host2 telnet localhost 64003 -- h3 host1 ssh root@localhost -p 64004 -- h4 host2 ssh root@localhost -p 64005
If all the virtual machines do not reach the running state, the command will never finish. Just type ctrl-C to exit and have a look at host log files to investigate the cause of the problem.
Once the scenario is started, you can interact with the different virtual machines directly through the consoles or, alternatively, as this example scenario has the virtual machines management interfaces activated (see <vm_mgmt> tag), you can connect them from the controller using the ssh tunnels configured. For example:
ssh root@localhost -p 64000 # to connect with h1 Ubuntu VM telnet localhost 64002 # to connect with dynamips r1 VM (remember to close r1 virtual console before connecting)
In case the virtual consoles are not opened automatically or if you close them, you can start them manually using the same parameters used in VNX (see VNX Console Management). For example:
ediv -f tutorial_ubuntu-dynamips.xml --console con0 -M h1
will open the graphical console of h1.
You also can execute commands over the virtual machines in the same way VNX does. For example, to start a web server on h3 and start a firefox web client in h1 that connects to h3 do:
ediv -f tutorial_ubuntu-dynamips.xml -x start-www -M h3 ediv -f tutorial_ubuntu-dynamips.xml -x www-h3 -M h1
You can restart a virtual machine conserving the changes made with:
ediv -f tutorial_ubuntu-dynamips.xml -d -M h2 ediv -f tutorial_ubuntu-dynamips.xml -t -M h2
Apart from the "-M" option used to specify a comma-separated list of virtual machines that restricts the execution of a command, EDIV includes a new option "-H" to specify a comma separated list of hosts and restrict command execution to hosts. For example, the following commands will restart all the virtual machines deployed to host2:
ediv -f tutorial_ubuntu-dynamips.xml -d -H host2 ediv -f tutorial_ubuntu-dynamips.xml -t -H host2
Finally, you can stop the whole scenario conserving virtual machine changes with:
ediv -f tutorial_ubuntu-dynamips.xml -d
Or deleting the changes with:
ediv -f tutorial_ubuntu-dynamips.xml -P
EDIV Cluster management commands
There are some useful EDIV commands you can use to manage the cluster:
- --check-cluster: checks the status of each host in cluster and shows VNX version installed
- --update-hosts: updates the VNX software in the cluster hosts (installs the version currently installed in the controller). By default, updates all cluster hosts. If '-H host_list' is used, only the hosts specified are updated. For example:
ediv --update-hosts # updated all cluster hosts ediv --update-hosts -H host1 # updates only 'host1'
ediv --clean-cluster # Restarts the whole cluster ediv --clean-cluster -H host1 # Restarts host1 (equivalent to execute 'vnx --clean-host' on host1)
Confirmation is requested before proceeding.
- with no aditional parameters, deletes the whole database content
- if a scenario name or scenario XML file is specified, only the database entries belonging to that scenario are deleted. For example:
vnx --reset-db scenario1 vnx --resed-db -f scenario1.xml
Other EDIV Commands
- --show-map: shows a map of the network scenarios build using graphviz. For example:
ediv -f tutorial_ubuntu-dynamips.xml --show-map
# ediv -f tutorial_ubuntu.xml --exe-info
...some stuff deleted...
---- mode: exe-info
---- Show info about scenario commands
User-defined command sequences for scenario 'tutorial_ubuntu'
----------------------------------------------------------------------------------
vnxtxtoff
calc
stop-www
start-www
calcoff
vnxtxt
xeyes2
www-h3
xeyes
www-h3-off
----------------------------------------------------------------------------------
