vSphere – Page 78

Standalone VMRC now available for Mac OS X

04.15.2015 by William Lam // 55 Comments

Last year, a standalone Virtual Machine Remote Console (VMRC) was released for Windows as part of vSphere 5.5 Update 2b which provides an alternative way of launching the VM console due to NPAPI deprecation. There was of course a huge request for Mac OS X support and the VMRC team has been working hard and today I am please to announce that standalone VMRC is now available for Apple Mac OS X which you can download using the following URL: www.vmware.com/go/download-vmrc

Note: Mac OS X 10.8 or greater is required to use the new Standalone VMRC. The release notes will be updated to reflect this requirement

There are currently two methods of launching a remote console to a Virtual Machine using the vSphere Web Client as seen in the screenshot below:

Using HTML5 VMRC simply by clicking on the thumbnail preview
Using the new Standalone VMRC by clicking on the "Launch Remote Console" link

When using the Standalone VMRC method, instead of opening the VM console in the browser, it will launch the native VMRC application on your system whether that be Windows or Mac OS X. All basic functionalities of the Standalone VMRC is available as you would expect such as power operations, device management, etc.

Note: There is not a specific version of vSphere that is required to directly launch the Standalone VMRC. However, to launch it within the vSphere Web Client, you will need vSphere 5.5 Update 2b or greater.

The other great thing about the Standalone VMRC is that it can function without vCenter Server and the vSphere Web Client and you can actually use it to connect to VM directly on an ESXi host. To use the VMRC without the vSphere Web Client, you will need to construct the VMRC URI which looks like the following:

vmrc://clone:[TICKET]@[HOST]:[PORT]/?moid=[VM-MOREF]

where TICKET is obtained by calling the AcquireCloneTicket() method using the SessionManager in vCenter Server. The HOST will either be the Hostname/IP Address of vCenter Server and the PORT should be default to 443 and you will need to specify the VM MoRef ID. In the case of a standalone ESXi host, you would just change the HOST property. If you do not wish to use the clone ticket, you can also just provide the following URI which will prompt for your ESXi credentials

vmrc://@[HOST]:[PORT]/?moid=[VM-MOREF]

Once you have generated the VMRC URI, you MUST launch it through a web browser as that is how it is passed directly to the Standalone VMRC application. In my opinion, this is not ideal especially for customers who wish to automatically generate this as part of a VM provisioning workflow to their end users and not having to require a browser to launch the Standalone VMRC application. If you have some feedback on this, please do leave a comment.

In the mean time, a quick workaround is to use the "open" command on Mac OS X along with the VMRC URI which will automatically load it into your default browser and launch the Standalone VMRC application for you.

open 'vmrc://clone:cst-VCT-52e44ad7-712f-9f45-a9ee-13ec6a74acaf--tp-B1-6F-91-F6-B5-8F-80-E5-FD-D6-E1-8B-10-F7-FE-15-C5-2A-75-41@192.168.1.60:443/?moid=vm-18'

UPDATE (05/31/15) - If you are connecting directly to an ESXi host you can either use the vSphere API to query for the VM MoRef ID or you can easily pull it by running the following command directly in the ESXi Shell:

vim-cmd vmsvc/getallvms

I am sure there are probably a few of you asking, what about for Linux users? Well, you can probably guess what is being worked on next 😉

Running Nested ESXi / VSAN Home Lab on Ravello

04.14.2015 by William Lam // 3 Comments

There are many options when it comes to building and running your own vSphere home lab. There are going to be different pros and cons to each of these solutions which you will need to evaluate things like cost, performance, maintenance, ease of use and complexity to name a few. Below is a list of the currently available options to you today.

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Duplicate MAC Address concerns with xVC-vMotion in vSphere 6.0

03.05.2015 by William Lam // 4 Comments

In vSphere 6.0, the mobility options for a Virtual Machine is truly limitless. This has all been possible with a new set of vMotion capabilities introduced in vSphere 6.0 which you can learn more about them here and here. In the past, one area of concern when migrating a VM from one vCenter Server to another is the possibility that a migrated VM's MAC Address might be re-provisioned by the source vCenter Server resulting in a MAC Address conflict. In fact, this is actually a topic I have covered before in my considerations when migrating VMs between vCenter Servers article. I highly encourage you check out that article before proceeding further as it provides some additional and necessary context.

When looking to leverage the new Cross vCenter Server vMotion (xVC-vMotion) capability in vSphere 6.0, are MAC Address conflicts still a concern? To answer that question, lets take a look at an example. Below I have a diagram depicting two different vSphere 6.0 deployments. The first is comprised of three vCenter Servers who are joined to the same SSO Domain called vghetto.local and VM1 is currently being managed by VC1. The second is a single vCenter Server connected to a completely different SSO Domain called vmware.local. I will also assume we are being a good VI Admin and we have deployed each vCenter Server using a unique ID (more details here on why having different VC ID matters).

Lets say we now migrate VM1 from VC1 to VC2. In previous releases of vSphere, this potentially could lead to VC1 re-provisioning the MAC Address that VM1 was associated with because that MAC Address was no longer being managed by VC1 and from its point of view, it is now available. Though this type of a scenario is probably rare in most customer environments, in a high churn continuous integration or continuous delivery environment, this can be a real issue. So has anything been improved in vSphere 6.0? The answer is yes, of course 🙂

In vSphere 6.0, vCenter Server now maintains a VM MAC Address Blacklist which upon a successful xVC-vMotion will update this blacklist with the MAC Addresses associated with the migrated VM. This ensures that the source vCenter Server will not re-provisioned these MAC Addresses to newly created VMs and these MAC Addresses are basically "blacklisted" from being used again as shown in the diagram below.

If we decide to migrate VM1 from VC2 back to VC1, the blacklist is automatically updated and "blacklisted" MAC Addresses will be removed. If we decide to migrate VM1 to a completely different vCenter Server which is not part of the same SSO Domain, ~~then the MAC Address could potentially be re-used~~, but it will depend on your environment if VC4 is on a completely different L2 segment, then a MAC Address conflict would not occur.

As of right now, there is no automatic way of reclaiming blacklisted MAC Addresses, it is a manual process that must be initiated through a private vSphere API. I am hoping we will be able to get this documented in an official VMware KB, so that in case this is required, you can easily follow the simple steps to execute the necessary APIs. Automatic reclamation is being looked at by Engineering and hopefully we will see this in a future patch/update in vSphere. Overall, this should should not really be a concern given that vCenter Server can uniquely generate about 65,000 unique MAC Addresses and you would have to perform quite a few xVC-vMotions before ever needing to reclaim from the blacklist.

One thing to be aware of when performing xVC-vMotion or ExVC-vMotion is that there are currently no pre-flight checks for MAC Address conflicts at the destination vCenter Server (something Engineering is looking update in a future patch/update release). Having said that, there are two additional measures you can implement in you environment to prevent MAC Address conflicts:

Create vCenter Server alarm which can detect and notify you of a duplicate MAC Address in you environment (also applicable to vSphere 5.5)
Pro-actively check to see if the existing MAC Addresses of your VM is currently in use prior to performing a xVC-vMotion, this is especially useful when performing ExVC-vMotion.

To help with with number 2, I have created a simple PowerCLI script called check-vm-mac-conflict.ps1 which accepts both your source and destination vCenter Server as well as the name of the VM in the source VC to be migrated. It will check the VM's MAC Addresses in the destination VC and ensure that there are no conflicts. If there is a conflict, it will output the name of the destination VM and the MAC Address that is in conflict as seen in the screenshot below.

Hopefully with these additional measures, you can easily prevent MAC Address conflicts when performing xVC-vMotions in your vSphere environment which can be a pain to troubleshoot.