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How to check when the VSAN Hardware Compatibility List (HCL) is updated?

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While catching up on emails from being out on paternity leave, I came across a VSAN HCL feature request that I had filed in early December of last year. I was pleasantly surprise to see that it had been marked resolved. The VSAN Hardware Compatibility List is continuously being updated to include new hardware platforms and components that have been certified by our hardware vendors.

This of course is great news for our customers, but one challenge that I have heard on several occasion is how to keep up with the changes, especially the addition of new components? The VSAN HCL allows you to subscribe and get notification on individual components which is useful to get the latest recommendation. However, in the case of new components being add or even removed, there is no easy solution and most folks resort to manually checking the VSAN HCL by hand.

VSAN itself does include an HCL healthcheck, which you can have it directly pull the latest VSAN HCL JSON from VMware's website, although this may not always be possible for customers without direct or proxy access to the internet. This means for customers who may have dark sites, they must periodically download the latest VSAN HCL JSON and distribute that throughout their vCenter Server, where as a more ideal solution is to only push the update when a new JSON has been provided by VMware.

My feature request was quite simple, it asks for a method in which customers can easily subscribe and get notified of when the VSAN HCL database has been updated. This has been delivered as a tiny RSS feed service.

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Automating Intel Sighting remediation using PowerCLI (SSH not required)

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In case you may not be aware, Intel recently notified VMware that certain Intel Broadwell and Haswell CPUs are affected by Intel Sighting after applying the latest microcode update to remediate against the Spectre vulnerability. VMware has published the following KB 52345 which provides more details on the affected Intel CPUs along with the recommended workaround in case you have already applied the latest ESXi patches containing the faulty microcode. I highly recommend you carefully read over the KB before, even if you have not applied the ESXi patches proceeding further.

With this updated news, I have also updated my existing Spectre verification script (found here) to include the additional Intel Sighting information which can help customers easily identify whether they have ESXi hosts that are impacted. In this article, I will provide a solution to help automate the deployment of the Intel Sighting remediation as outlined in the KB article, but unlike the manual steps outlined in the KB, SSH access to the underlying ESXi host will NOT required.

Step 1 - Download the VerifyESXiMicrocode.ps1 PowerCLI script as well as the new PowerCLI script IntelSightingWorkaround.ps1

Step 2 - Run the "Verify-ESXiMicrocodePatch" function against a specific vSphere Cluster or ESXi host to determine if you are impacted by the Intel Sighting issue. Below is a screenshot for a system which is affected by Intel Sighting and we can determine this by seeing a value of "True" under the IntelSighting column.


Step 3 (Optional) - This step is optional, but I wanted to demonstrate how you can tell whether the Intel Sighting workaround has been applied correctly. You can use the "Verify-ESXiMicrocodePatchAndVM" function which provides information from a Virtual Machine's perspective and whether the new CPU instructions are exposed to the VM. In the screenshot below, I have a Test VM called TestVM-03 that has been powered on and as you can see, the three new CPU instructions (IBR,IBPB and STIB) are present as I have not applied the Intel Sighting workaround.


Step 4 (Optional) - This step is also optional, but I wanted to demonstrate how you can quickly check the contents of /etc/vmware/config without requiring SSH access or direct ESXi Shell access. You can use the "Get-Esxconfig" function and specify an ESXi host to query. The screenshot below confirms that we have not deployed the Intel Sighting workaround.


Step 5 - Once we have identified the ESXi hosts that are impacted by Intel Sightin (See step 2), we need to create a text file that contains the Hostname/IP of ESXi hosts (one on each line) that we wish to remediate. This will then be used as an input to the remediation function. In the example here, I have a single host to remediate and have added its name to a file that I have called "affected_hosts".txt (it can be named anything).

Note: The remediation does NOT require the ESXi host to reboot for the changes to go into effect, but you may still want to consider following standard procedures of putting the host into Maintenance Mode if you wish to control when VMs will see the masked instruction which will require a VM power cycle (OS restart is not sufficient).

To apply the remediation, you will use the "Set-IntelSightingsWorkaround" function which has a single mandatory parameter called AffectedHostList. Below is a screenshot of running the function and the remediation is fairly quick as it is merely appending a single string to the /etc/vmware/config configuration file. After the remediation has completed, we can then use the "Get-Esxconfig" function to confirm that we have added the masked CPU instruction to the ESXi host as shown in screenshot below.


Step 6 - As the KB mentions, for the changes to go into affect, you will need to perform a complete power cycle of your VMs before they can see the new masked CPU instructions. If you recall earlier, I had a VM called TestVM-03 which saw the three new CPU instructions. If we power cycle the VM and re-run the "Verify-ESXiMicrocodePatchAndVM" function against our VM, we should now see that the three CPU instructions have been properly masked away as shown in the screenshot below.


When it is time to remove the workaround, the process is also very straight forward as well. You can use the "Remove-IntelSightingsWorkaround" function which also accepts a list of ESXi hosts to remediate. Once the remediation has completed and you wish to expose the new CPU instructions to the VMs, you will also need to power cycle the VMs for CPU instructions to be unmasked.

Cloudafied Desktops: HP RGS on Amazon EC2

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Provided is a quick recording of how RGS (v5.1.5) performs on a "cloud" hosted machine when playing Flash and Quicktime videos. The capture software that we used made the video a little sluggish (as can be seen from the not-so-smooth mouse movements which should otherwise be smooth when using RGS regardless of connection quality). User interface performance was crisp and interaction was very near to the all important “local feel” (which is uncharacteristic of RDP connections).

A Windows AMI configured as a "High-CPU Medium (c1.medium)" instance type was selected for this session. The HP RGS image quality was arbitrarily set to 50% to conserve bandwidth and processing load. As this is an initial proof of concept, we did not optimize the image quality parameter and as so it will be left as an additional exercise in the future. Due to time constraints, common office productivity software was not tested and demonstrated on the cloudafied desktop however we strongly believe that RGS would perform well in this area as most common office productivity software is static and thus not bound by the CPU and connection bandwidth requirements necessary for dynamic multimedia content.

We believe that performance can be improved because the EC2 hosted Windows machine is not running an optimized video driver, that is, it is using the standard Windows VGA adapter driver. This drawback limits the maximum desktop size to 1280x1024 (without explicit hacks to increase the resolution capability if at all possible). Additionally, an older version of RGS was used during testing on an operating system not intended for desktop use (although changing processor scheduling and memory usage parameters may improve apparent desktop performance); newer versions of RGS running on the intended platforms may offer improved performance. Despite these drawbacks, multimedia performance was still surprisingly satisfactory.

And now to the video:
http://engineering.ucsb.edu/~duonglt/vmware/RGSonEC2