virtuallyGhetto

vcsim

govcsim – Neat incubation project (vCenter Server & ESXi API based simulator)

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I know many of my readers have inquired about VCSIM (vCenter Server Simulator) which was a really useful tool that served a variety of use cases, but unfortunately it had stopped working with the VCSA 6.0 release. VCSIM is another topic that is near and dear to me and it is something I continue to push and advocate for internally at VMware. Earlier this week, I came to learn about a cool new incubation project that Doug MacEachern had been working on for some time now. Doug is an awesome VMware developer working on the vSphere Integrated Containers (vIC) project and he is also well known for his active contributions to both govmomi (vSphere SDK for Go) and govc CLI.

As you can probably guess from the title, the name of the project is called govcsim and it is a vCenter Server and ESXi API based simulator written using govmomi. It creates a vCenter Server model with a datacenter, hosts, cluster, resource pools, networks and a datastore. The naming of the objects is similar to that of the original VCSIM mode that was included with the VCSA. The number of resources can be increased or decreased using the various resource type flags. Resources can also be created and removed using the API. Doug had developed the tool to provide an easy way for their team to test some of the work they are doing with vIC. The tool is still under incubation but continues to received enhancements. In fact, the other day when I had used it for the first time, I had found a couple of issues which Doug resolved immediately.

I got a chance to give govcsim a spin the other day and currently you can connect to it using govmomi, govc, pyvomi (vSphere SDK for Python) or rbvmomi (vSphere SDK for Ruby). It currently does not work with PowerCLI (connects but no inventory), I know this is something Doug is currently looking into. You might also be able to connect using other vSphere SDKs but these are the ones that Doug and I have tried so far.

[Read more...] about govcsim – Neat incubation project (vCenter Server & ESXi API based simulator)

Quick Tip – VCSIM no longer works in VCSA 6.0

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I figured I do a quick blog post on the topic of VCSIM and VCSA 6.0 since I have received several questions regarding its functioanlity in VCSA 6.0. The simple and unfortunate answer is that VCSIM no longer functions in the latest VCSA 6.0. There have been enough changes to the vSphere 5.x and vSphere 6.0 code base that this internal tool will no longer function. As far as I know, there are no plans of changing this as VCSIM was primarily used internally by our Developers for certain types of functional testing. I know I will miss using the tool as it did come in handy!

UPDATE (04/23/17) - For those interested in VCSIM, there is a new project called govcsim. For more details check it out here.

VCSIM should continue to work in both VCSA 5.1 and 5.5 and you can find more details in the articles below.

Feedback needed for the future of VCSIM

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Last week, I had a chance to catchup with a couple of folks over in our Performance Engineering team to talk about VCSIM. For those of you who have not heard of VCSIM before or would like to know how to get started, I highly recommend you check out this article here and here for more details. We had a discussion on a variety of topics including how I and some of our customers are using VCSIM today.

As some of you already know, VCSIM is an internal tool originally developed by VMware Engineering for a very specific set of use cases, it was never intended to be used by our customers. Having said that, I think after talking to Engineering, they understood the value in having such a tool which could be useful to both our customers and partners. In fact, I have even shared a couple of use cases that I believe VCSIM can greatly benefit everyone:

  • Exploring and learning about the vSphere API and the basic inventory hierarchy of vSphere objects
  • Environment to develop and create various inventory reporting scripts (vCLI, PowerCLI, etc)
  • Developing performance metric gathering tools
  • Developing vSphere Web Client plugins and being able visualize large inventory of objects

There were some thoughts on how VCSIM could evolve over time from its current implementation as it was designed for a very specific purpose, but it was too early to tell and it would be based on some assumptions. Instead, I thought it might be useful to get feedback into Engineering so they could better understand how VCSIM was currently being used today. To help with this, I have created a very short survey below or you can also directly access it using the link here. Please take a few minutes to provide some feedback on how you currently use VCSIM today. Thanks in advance!

Additional VCSIM Resources:

Simulating vSphere Performance Metrics using VCSIM

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A really useful tool that I leverage from time to time is VCSIM (vCenter Simulator) which can be found within the VCSA (vCenter Server Appliance). VCSIM allows you to easily "simulate" a custom vSphere Inventory that can be used for a variety of use cases including custom reports using the vSphere API/CLIs. There are additional capabilities that VCSIM provides and one that I have not explored much is the simulation of vSphere Performance Metrics. Having received a couple of inquires regarding VCSIM and performance metrics, I figure this would be a good opportunity to explore this feature in a bit more detail.

Disclaimer: This is not officially supported by VMware, use at your own risk.

Before getting starting, you should familiarize yourself with VCSIM by reading these two articles here and here.

By default when running VCSIM, there are no Performance Metrics. If you wish to include it, you will need to ensure the following two lines are added to your VCSIM configuration file:

<perfCounterInfo>vcsim/model/PerfCounterInfo.xml</perfCounterInfo>
<metricMetadata>vcsim/model/metricMetadata.cfg</metricMetadata>

The first file contains the performance metric definitions that are supported and the second file will specify which metrics will be simulated. To demonstrate the performance metric capabilities of VCSIM, I will be using the following configuration files which you can just copy/paste:

vghetto-perf-vcsim.cfg - This will be our VCSIM configuration file

vghetto-perf-inventory.cfg - This will be our VCSIM inventory configuration file

To ensure everything is working, we can start VCIM by issuing the following command on the VCSA:

vmware-vcsim-start /etc/vmware-vpx/vcsim/model/vghetto-perf-vcsim.cfg

If everything is working, you should be able to login using the vSphere Web/C# Client to view the small inventory we just created. If you are able to see the inventory, then go ahead and stop VCSIM by issusing the following command:

vmware-vcim-stop false

Note: To ensure our inventory is not destroyed each time, you should pass in the 'false' flag else it will automatically be deleted each time. This is useful if you want to preserve your inventory on subsequent reboots.

For all Performance Metric configurations, you will only need to edit the metricMetadata.cfg file. VCSIM supports four different types of Stats model:

  1. Constant
  2. Linear
  3. Square
  4. Triangle

We will take a look at Stats model for 2-4 since the Constant is not all that interesting 🙂 For our examples, we will take a look at each Stats model for the datastore.datastoreIops.average metrics.

Linear Stats Model:

vcsim-perf-linear

Square Stats Model:

vcsim-perf-square

Triangle Stats Model:

vcsim-perf-triangle

I thought this was pretty neat that the VCSIM developers included a couple of Stats Models that could be leveraged right out of the box! As you can see, it is pretty easy to enable various performance metrics simply by identifying the metric(s) you are interested in and specifying the Stats Model and then starting up VCSIM. The other neat thing that I have been asked about before is can VCSIM simulate performance metrics for specific vSphere entities? I originally thought the answer was no until I started to play with the performance metric simulator a bit more and realize there is a List property that you can use to specify the specific objects in which you want data to be displayed.

Here is an example of of the same performance metric we have been looking at but only enabling it for two Datastores:

vcsim-perf-list

 Note: One thing I noticed while playing with the performance metric simulator is that some times the object in the UI is blank when using the vSphere Web Client. If I use the vSphere C# Client, it is perfectly fine and that is also true if you are using the vSphere API to query for these metrics.

Hopefully this was a good overview of how the VCSIM performance metrics feature works. I know there are a couple of internal folks who have used VCSIM injunction with vCenter Operations and I am also curious to see what other neat uses cases exists for the performance metrics feature. Also, if you have created a really cool metricMetadata.cfg configuration file, feel free to share with the rest of the community!

Quick Tip – Adding a custom prefix to your VCSIM environment

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I just discovered this neat little feature of VCSIM (vCenter Server Simulator) which allows you to append a global string prefix to all vSphere objects in your inventory. I am not sure if this capability has always been there but definitely can be useful if you plan on running multiple VCSIM environments, this can be an easy way to uniquely identify a particular configuration.

Screen Shot 2014-03-16 at 10.46.56 AM
To add the custom prefix, you will need to add the <prefix></prefix> tags to your VCSIM inventory configuration file. You can take a look at the default template /etc/vmware-vpx/vcsim/model/initInventory.cfg to get an idea of the available configurations.

Here is a the sample VCSIM configuration file for the inventory in the screenshot above:

 

New vCenter Server Simulator 2.0 enhancements in VCSA 5.5

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Last year I wrote about a very interesting tool called vCenter Server Simulator (VCSIM) which allows a user to quickly simulate a VMware environment that can be comprised of thousands of ESXi hosts and virtual machines. VCSIM can benefit a variety of use cases such as learning about the vSphere API, creating reports for vSphere or vCloud Director to building vSphere Web Client plugins to help visualize large inventories. There was an overwhelming interest in VCSIM from last year and I received some great feedback and feature requests which I fed back to the VMware engineers who developed this internal tool.

With the upcoming version of vSphere 5.5 to be released very soon, I was wondering if there were going to be any new features for VCSIM in VCSA 5.5? I reached out to one of the engineers, Haiping Yang, who works in the Performance Engineering team who is currently taking over some of the development of VCSIM. Some of you might be familiar with some of her work such as the recent visualEsxtop, esxtop and resxtop to just name a few. In talking to Haiping, I found that she has been quite busy adding cool new features to VCSIM and this is on top of her regular day job!

Disclaimer: This is not officially supported by VMware, please use at your own risk.

Here is a quick summary of the new features of VCSIM 2.0:

Distributed Virtual Switch (VDS) Support:

  • Add / Remove ESXi hosts from VDS
  • Create / Delete Distributed Virtual Portgroup
  • Reconfigure Distributed Virtual Portgroup
    • Add / Remove VM from Distributed Portgroup

vCloud Networking & Security (vCNS) Support:

  • Create / Delete vCNS Gateway
  • Create / Delete Isolated/Routed Org Networks
  • Create / Delete vApp Networks
  • Deploy / Undeploy vApp with DHCP service enabled

Persistent Inventory Configuration upon restart:

  • Folder, Cluster, Resource Pool, Host, Datastore, Virtual Machine, Network and VDS

Custom Configuration Support:

  • ESXi version template
  • ESXi configuration template
  • Datastore configuration
  • Virtual Machine datastore

Easy startup commands:

  • vmware-vcsim-start
  • vmware-vcsim-stop [true|false] - Determines whether the inventory is cleared after stopping VCSIM

Note: Before you can use VCSIM, you will need to configure the VCSA as you normally would by going through the VAMI interface or running through the SSH commands noted in this article.

I will not go over every single feature mentioned above, but I did want to take a look at a few noteworthy features such as the new VCSIM start/stop command, datastore configuration and ESXi host configuration templates.

VCSIM Start/Stop Commands:

With the previous version of VCSIM, you had to manually edit the vCenter Server configuration file (vpxd.conf) and append the necessary VCSIM configurations. In this release, we now have an easy to use command-line utility to start and stop VCSIM. The vmware-vcsim-start command supports several startup options.

To view the list of supported options, just run the following command:

vmware-vcsim-start help

Option 1 - You can specify a VCSIM configuration file and you can find several examples located in /etc/vmware-vpx/vcsim/model

Option 2 - You can specify either the keyword "empty" for a blank vSphere inventory or "default" which will automatically use /etc/vmware-vpx/vcsim/model/vcsim-default.cfg inventory configuration

Option 3 - You can just specify the inventory layout on the command-line. An example would be "custom:dc=1,cluster=1,rp=1,host=1,vm=1,vm_on=1,latency=true"

To get a list of all the available VCSIM configurations, take a look at /etc/vmware-vpx/vcsim/model/vcsim.cfg.template

Here is an example of starting VCSIM using the "default" mode:

vmware-vcsim-start default

 

Datastore Configuration:

Custom datastore configuration was something that was much sought after with VCSIM 1.0 and unfortunately, there was only a single global datastore that was automatically "connected" to all simulated ESXi host. The new version of VCSIM now supports custom datastore configurations that can be defined globally, at the cluster level, local storage as well as string prefix which can help you separate out different VCSIM instances.

Here is an example of the configuration that would need to be added to the VCSIM configuration file:

Here is what one of the simulated ESXi hosts would show for its datastores:

 

ESXi Configuration Template:

Another useful feature that I personally have asked for is the ability to customize an individual simulated ESXi host. Though this is still currently a work in progress, what you can do with VCSIM 2.0 is to customize the ESXi host version as well as the datastores on a per host basis. If you take a look vcsim.cfg.template, you will find a configuration line that looks like:

vcsim/model/hostConfig

This specifies a directory that would contain custom simulated ESXi host templates and their configurations. A sample host template is provided at /etc/vmware-vpx/vcsim/model/hostConfig.xml.template and currently, you need to specify the default simulated hostname (e.g. DC0_C0_H0.xml).

Here is an example of what that host template can look like:

Now if we go back to our DC0_C0_H0 ESXi host, you will see that the host template will override the global configuration:

For the two examples above, here is what I used in my custom VCSIM configuration file that I called vcsim-virtuallyghetto.cfg if you are interested in what I used:

I have already asked for the ability to fully customize the simulated ESXi host display name and have already been told that this is something they would consider for a future release. VCSIM 2.0 has also been improved to better operate with vCloud Networking & Security and vCloud Director. I was able to quickly test VCSIM 2.0 with the latest version of vCloud Director 5.5 and everything seems to be working fine. You can follow the existing instructions here for vCloud Director setup with VCSIM.

As you can see VCSIM 2.0 contains many new features and I highly encourage you to give it a spin when vSphere 5.5 is made generally available. There are definitely some additional fit and finish features that Haiping just could not get into this release. Hopefully we will get those updates in a future release of VCSIM and include additional ESXi template versions. If you have any feedback, comments or feature requests feel free to leave a comment and I will make sure it reaches Haiping and the development team. I do not want to spoil the surprise, but I just want to say one of the features coming in VCSIM 3.0 will be quite AWESOME! 😀 (sorry for the tease)