VSAN – Page 18

Getting Started with Tech Preview of Docker Volume Driver for vSphere

05.31.2016 by William Lam // 8 Comments

A couple of weeks ago, I got an early sneak peak at some of the work that was being done in VMware's Storage and Availability Business Unit (SABU) on providing storage persistency for Docker Containers in a vSphere based environment. Today, VMware has open sourced a new Docker Volume Driver for vSphere (Tech Preview) that will enable customers to easily take advantage of their existing vSphere Storage (VSAN, VMFS and NFS) and provide persistent storage access to Docker Containers running on top of the vSphere platform. Both the Developers and vSphere Administrators will have familiar interfaces in how they manage and interact with these Docker Volumes from vSphere, which we will explore further below.

The new Docker Volume Driver for vSphere is comprised of two components: The first is the vSphere Docker Volume Plugin that is installed inside of a Docker Host (VM) that will allow you to instantiate new Docker Volumes. The second is the vSphere Data Volume Driver that is installed in the ESXi Hypervisor host that will handle the VMDK creation and the mapping of the Docker Volume request back to the Docker Hosts. If you have shared storage on your ESXi hosts, you can have a VM on one ESXi host create a Docker Volume and have a completely different VM on another ESXi host mount the exact same Docker Volume. Below is diagram to help illustrate the different components that make up the Docker Volume Driver for vSphere.

Below is a quick tutorial on how to get started with the new Docker Volume Driver for vSphere.

Pre-Requisites

vSphere ESXi 6.0+
vSphere Storage (VSAN, VMFS or NFS) for ESXi host (shared storage required for multi-ESXi host support)
Docker Host (VM) running Docker 1.9+ (recommend using VMware Photon 1.0 RC OVA but Ubuntu 10.04 works as well)

Getting Started

Step 1 - Download the vSphere Docker Volume Plugin (RPM or DEB) and vSphere Docker Volume Driver VIB for ESXi

Step 2 - Install the vSphere Docker Volume Driver VIB in ESXi by SCP'ing the VIB to the ESXi and then run the following command specifying the full path to the VIB:

esxcli software vib install -v /vmware-esx-vmdkops-0.1.0.tp.vib -f

Step 3 - Install the vSphere Docker Volume Plugin by SCP'ing the RPM or DEB file to your Docker Host (VM) and then run one of the following commands:

rpm -ivh docker-volume-vsphere-0.1.0.tp-1.x86_64.rpm
dpkg -i docker-volume-vsphere-0.1.0.tp-1.x86_64.db

Creating Docker Volumes on vSphere (Developer)

To create your first Docker Volume on vSphere, a Developer would only need access to a Container Host (VM) like PhotonOS for example that has the vSphere Docker Volume Plugin installed. They would then use the familiar Docker CLI to create a Docker Volume like they normally would and there is nothing they need to know about the underlying infrastructure.

Run the following command to create a new Docker Volume called vol1 with the capacity of 10GB using the new vmdk driver:

docker volume create --driver=vmdk --name=vol1 -o size=10gb

We can list all the Docker Volumes that available by running the following command:

docker volume ls

We can also inspect a specific Docker Volume by running the following command and specifying the name of the volume:

docker volume inspect vol1

Lets actually do something with this volume now by attaching it to a simple Busybox Docker Container by running the following command:

docker run --rm -it -v vol1:/mnt/volume1 busybox

As you can see from the screenshot above, I have now successfully accessed the Docker Volume that we had created earlier and I am now able to write to it. If you have another VM that resides on the same underlying shared storage, you can also mount the Docker Volume that you had just created from a different system.

Pretty straight forward and easy right? Happy Developers 🙂

Managing Docker Volumes on vSphere (vSphere Administrator)

For the vSphere Administrators, you must be wondering, did I just give my Developers full access to the underlying vSphere Storage to consume as much storage as possible? Of course not, we have not forgotten about our VI Admins and we have some tools to help. Today, there is a CLI utility located at /usr/lib/vmware/vmdkops/bin/vmdkops_admin.py which runs directly on the ESXi Shell (hopefully this will turn into an API in the future) which provides visibility into how much storage is being consumed (provisioned and usage) by the individual Docker Volumes as well as who is creating them and their respective Virtual Machine mappings.

Lets take a look at a quick example by logging into the ESXi Shell. To view the list ofDocker Volumes that have been created, run the following command:

/usr/lib/vmware/vmdkops/bin/vmdkops_admin.py ls

You should see the name of the Docker Volume that we had created earlier and the respective vSphere Datastore in which it was provisioned to. At the time of writing this, these were the only two default properties that are displayed out of the box. You can actually add additional columns by simply using the -c option by running the following command:

/usr/lib/vmware/vmdkops/bin/vmdkops_admin.py ls -c volume,datastore,created-by,policy,attached-to,capacity,used

Now we get a bunch more information like which VM had created the Docker Volume, the BIOS UUID that the Docker Volume is currently attached to, the VSAN VM Storage Policy that was used (applicable to VSAN env only), the provisioned and used capacity. In my opinion, this should be the default set of columns and this is something I have feedback to the team, so perhaps this will be the default when the Tech Preview is released.

One thing that to be aware of is that the Docker Volumes (VMDKs) will automatically be provisioned onto the same underlying vSphere Datastore as the Docker Host VM (which makes sense given it needs to be able to access it). In the future, it may be possible to specify where you may want your Docker Volumes to be provisioned. If you have any feedback on this, be sure to leave a comment in the Issues page of the Github project.

Docker Volume Role Management

Although not yet implemented in the Tech Preview, it looks like VI Admins will also have the ability to create Roles that restrict the types of Docker Volume operations that a given set of VM(s) can perform as well as the maximum amount of storage that can be provisioned.

Here is an example of what the command would look like:

/usr/lib/vmware/vmdkops/bin/vmdkops_admin.py role create --name DevLead-Role --volume-maxsize 100GB --rights create,delete,mount --matches-vm photon-docker-host-*

Docker Volume VSAN VM Storage Policy Management

Since VSAN is one of the supported vSphere Storage backends with the new Docker Volume Driver, VI Admins will also have the ability to create custom VSAN VM Storage Policies that can then be specified during Docker Volume creations. Lets take a look at how this works.

To create a new VSAN Policy, you will need to specify the name of the policy and provide the set of VSAN capabilities formatted using the same syntax found in esxcli vsan policy getdefault command. Here is a mapping of the VSAN capabilities to the attribute names:

VSAN Capability Description	VSAN Capability Key
Number of failures to tolerate	hostFailuresToTolerate
Number of disk stripes per object	stripeWidth
Force provisioning	forceProvisioning
Object space reservation	proportionalCapacity
Flash read cache reservation	cacheReservation

Run the following command to create a new VSAN Policy called FTT=0 which sets Failure to Tolerate to 0 and Force Provisioning to true:

/usr/lib/vmware/vmdkops/bin/vmdkops_admin.py policy create --name FTT=0 --content '(("hostFailuresToTolerate" i0) ("forceProvisioning" i1))'

If we now go back to our Docker Host, we can create a second Docker Volume called vol2 with capacity of 20GB, but we will also now include our new VSAN Policy called FTT=0 policy by running the following command:

docker volume create --driver=vmdk --name=vol2 -o size=20gb -o vsan-policy-name=FTT=0

We can also easily see which VSAN Policies are in use by simply listing all policies by running the following command:

All VSAN Policies and Docker Volumes (VMDK) that are created are stored under a folder called dockvols in the root of the vSphere Datastore as shown in the screenshot below.

Hopefully this gave you a nice overview of what the Docker Volume Driver for vSphere can do in its first release. Remember, this is still in Tech Preview and our Engineers would love to get your feedback on the things you like, new features or things that we can improve on. The project is on Github which you can visit the page here and if you have any questions or run into bugs, be sure to submit an issue here or contribute back!

VSAN Management 6.2 API Quick Reference

05.31.2016 by William Lam // 2 Comments

With the release of VSAN 6.2 (vSphere 6.0 Update 2), a new VSAN Management API has been introduced which covers all aspects of VSAN functionality including: complete lifecycle (install, upgrade, patch), monitoring (including VSAN Observer capabilities), configuration and troubleshooting. Although there is a well documented VSAN Management API Reference Guide which you can navigate around, I personally find it useful to be able to have a quick reference to all the APIs in on place which I can easily search and reference. This is especially true when I am learning about a new API.

With that, I have created a "Quick Reference" of the new VSAN 6.2 Management API. You can find a screenshot below as well as the direct link to the quick reference. I used Draw.io to create the diagram but it is not just a static image of all the new Managed Objects and their respective methods, but each API method also links back to the VSAN Management API Reference Guide and best of all, because it is in HTML, you can easily search in the quick reference itself.

I initially had created this for myself, but I figure that others could also benefit. I am curious if others find this useful and whether we should have something like this as part of the official VSAN Management API Reference Guide?

VSAN Management 6.2 API Quick Reference: https://s3.amazonaws.com/virtuallyghetto-download/vsanapi.html

Adding custom VSAN BIOS splash screen to the Intel NUC

03.06.2016 by William Lam // 5 Comments

One of the last things I wanted to look into after setting up my new VSAN 6.2 home lab on the new 6th Gen Intel NUC was to add a custom BIOS splash screen giving my system a personal touch. Updating the BIOS splash screen would require flashing the BIOS itself which gave me some concerns after hearing about the BIOS v33 issue in which the M.2 slot would no longer be detected after the update. Although there was a simple workaround after the update, I still wanted to be cautious. Over the weekend I had noticed that Intel had released BIOS v36 for the Intel NUC which resolved the M.2 issue among a few others. I decided to give it a shot and hope that I that I do not brick my NUC.

I am happy to say that I was successful in updating to the latest Intel NUC BIOS and as you can see from the screenshot below, I was also able to replace the default Intel BIOS splash screen with a Captain VSAN BIOS splash screen (TV is 46" for those wondering) 🙂

The process for building and customizing your Intel NUC BIOS is relatively straight forward but because I waited until after I had everything installed, it ended up being a bit more work than I had hoped. To customize your BIOS, Intel provides a Microsoft Windows only utility called Intel Integrator Toolkit. The easiest way to build and update your BIOS is to initially start off by installing Microsoft Windows on the Intel NUC itself which then allows you to easily flash the BIOS using the executable that is generated from the toolkit. Since I had already consumed both of my SSDs for VMware VSAN and Microsoft Windows does not allow you to install its OS directly onto a USB device, I had to use this method here to install a bootable version of Microsoft Windows onto the USB device since I did not want to blow away my VSAN setup.

OK, so now onto the cool stuff. Below are the instructions on how to build and customize your BIOS for the Intel NUC. If you would like to use the exact same BIOS splash screen as well as update to the latest BIOS v36 and do not want to go through the hassle, I have made my custom VSAN BIOS image available here. You just need to download the executable and run it on the Intel NUC itself which must be running Microsoft Windows (I used 8.1) and then follow the screens on flashing your BIOS.

Step 1 - Download the following two packages and transfer them to Microsoft Windows image running on your NUC:

Step 2 - Install the Intel Integrator Toolkit and then start the program

Step 3 - Select the "Customize a BIOS file" option and load either the custom VSAN BIOS image which I have made available here OR load the NUC BIOS v36 file you had downloaded earlier.

Step 4 - In the lower left hand corner, browse for the graphic image that you wish to use for your BIOS splash screen (images with black background works the best). For those interested, you can find the Captain VSAN image that I had used here. The tool actually supports several image formats in addition to the default BMP such as JPEG and PNG, you just need to change the extension type. There is a size limitation, but the nice thing about the tool is that there is an option to compress the image when it detects it is too large. Make sure to change the image for the four different options by clicking on the drop down wizard. I thought I only had to replace the first image but it looks like other versions of the splash screen is also used and it is best to just replace them all. You also have the option of changing other default settings in the BIOS, feel free to click on the tooltip for details on each of the options.

Step 5 - Once you are done customizing your BIOS, you will then save your changes and the tool will produce a single Windows executable (SY0036.exe) which you will run on the NUC itself to flash the BIOS. You will be prompted with a couple of questions and once the process begins, it will restart and you will need to confirm one more time before the imaging process starts. If everything was successful, you should now see a new BIOS splash screen replacing the default Intel image. There is a good chance you may go through this process a few times depending if you are happy with the splash screen display. I think it took me about three tries. Hope this helps anyone looking to add that personal touch to their home lab!