vSphere - 18

You’re about to enter a world where creating a Virtual Machine hot-clone is done faster than powering it off. My former Capgemini colleagues, Ernst Cozijnsen and John van der Sluis recently implemented EMC PowerPath/VE, here's their story.

It took the guys in storage land a long time to deliver.... But finally it's there.... A really great kick-ass plug-in to boost your vSphere 4 storage performance through the roof.

In prior versions of ESX the Native Multi Pathing “NMP” plug-in was available for balancing the storage load over different Fiber Channel HBA’s and storage paths to your storage array(s). Beside that it’s not really “Multi Pathing” it had another major disadvantage of being able to stress your storage array in such a way it could crash.  (Yes.. we know how it works and yes… we succeeded in this). This crashing didn’t had much to do with ESX but more with how the storage arrays  handle the different request coming in from the FA port and distributing the load across the storage processors inside the box.

If commands for e.g. LUN-A come in via 2 different FA ports on the array which all  have their own storage processor, there needs to be a lot of “inter communication” between the storage CPU’s inside the box. For a normal environment this is no issue but when you start to stretch the limit this can and will cause major concerns. Therefore I have written this script.

At October 19th (week 43) and November 9th (week 46) I will deliver one of the first VMware vSphere Fast Track training courses. There are still some seats left, so I would be very glad if you can join me at this hands-on training course.

VMware vSphere: Fast Track

This intensive, extended-hours training course focuses on installing, configuring, managing, and troubleshooting VMware vSphere. It combines the content of the VMware vSphere 4: Install, Configure, Manage course with advanced tasks and skills for configuring a highly available and scalable virtual infrastructure. Upon completing this course, you can take the examination to qualify as a VMware Certified Professional.

Course Objectives

•Install and configure VMware ESX™/ESXi, vCenter™ Server, and the vSphere Management Assistant
•Configure, manage, and troubleshoot ESX/ESXi networking and storage
•Create, configure, migrate, manage, convert, and monitor virtual machines and virtual appliances
•Scale the vSphere virtual infrastructure
•Implement business continuity solutions
•Manage changes to the vSphere environment

You can use this link to register:

http://www.globalknowledge.nl/Default.aspx?page=461&coursecode=VSFT

VMware wants to know how you make your customers’ time and money count more with VMware vSphere. Here are two new programs for your small and midsized customers with fewer than 1000 employees and/or less than 100 servers before virtualization!

Tell VMware Your Story

Encourage your customers to share how you and VMware have helped their business succeed and you could win up to three passes to Partner Exchange 2010 and get a one-page joint-customer success story published on vmware.com. Just be sure to have your customers include your company name in the Partner section of the contest entry form.  In addition, your customers could win an iPod Touch for participating! Send your customers to www.vmware.com/go/tellusyourstory today.

Time to Save with VMware Video Contest

Get your customers to create a video that demonstrates why VMware is the right choice for small and midsize businesses and they could win big! Prizes include $5,000 cash, Apple MacBook Pro laptops with VMware Fusion®, 5th-generation iPod nanos, and t-shirts. Be sure to have them mention your company that helped them achieve it all!
See all the details at www.vmware.com/go/timetosave/contest.

While one of my readers (credits to Scoobie Guy) was exploring the features of DV switches he inadvertently discovered if you make major changes (or rebuild)  your virtual center instance, or remove a host from a VC instance you may end up with the following errors:

The distributed Virtual Switch corresponding to the proxy switches d5 6e 22 50 dd f2 94 7b-a6 1f b2 c2 e6 aa 0f bf on the host does not exist in vCenter or does not contain the host.


 
From this article: http://www.vmware.com/support/vsphere4/doc/vsp_esxi40_vc40_rel_notes.html#knownissues

Here is an explanation: Removing an ESX/ESXi host configured with a vDS from a vCenter Server system results in inconsistent networking state on the host. If you remove an ESX/ESXi host configured with a vDS from a vCenter Server system, the host cannot reconnect to the vDS. When you add the host back to the vCenter Server system, a warning similar to the following appears:

The distributed Virtual Switch corresponding to the proxy switches d5 6e 22 50 dd f2 94 7b-a6 1f b2 c2 e6 aa 0f bf on the host does not exist in vCenter or does not contain the host.

The virtual machines continue to function on their respective ports, but new virtual machines are not allowed to power on. You cannot modify the vDS settings for this host by using a vSphere Client connected to the vCenter Server system.

Workaround: Perform the following steps:

1. Use a vSphere Client to connect directly to the ESX/ESXi host. This workaround requires a direct connection.
2. Migrate the virtual machines off of the invalid vDS ports one by one by editing the settings of each virtual machine. This will result in prolonged network interruption to the virtual machines.
3. Choose Host > Configuration > Networking > Distributed Virtual Switch and click Remove.
4. In a vSphere Client connected to the vCenter Server system, refresh the network settings of the host. The errors are cleared.
5. Add the host back to the vDS, either manually or by using a host profile.
6. Migrate the virtual machines back to their respective ports or portgroups on the vDS. To do so, right-click the vDS and choose Migrate Virtual Machine Networking. This process also results in network interruption to the virtual machines. 
   

Now the fun / trouble really starts! Rebuilding your network!

Another thing to note, if you miss configure a DvSwitch you may lose all connectivity to your ESX hosts. Examples are the MTU settings change from 1500 to 9000, if your NICs or Switch don’t support it then you will lose connectivity. My recommendation is to keep at least one  service console port on a standard virtual switch. That way you can always reach your hosts, and worse case if you need to rebuild your service console network it’s much easier.

Nice trackback from Mike Laverick: Got a question for you. Preparing to start a new vSphere farm and trying to decide do I use stand switches or start with the DVS. Especially when I see this: http://www.ntpro.nl/blog/archives/1283-vSphere-DvSwitch-caveats-and-best-practices!.html So the main question is do we think this is mature enough to go forward with yet? Can I use Host profiles with DVS safely? --> http://www.rtfm-ed.co.uk/?p=1875

You really should check out the new VMware vSphere Blog, it’s a central place for news, commentary, links to new resources and other information about VMware vSphere. I’ve seen some great articles popping up in the last two weeks.

Eric Siebert - Master’s guide to VMware Fault Tolerance
Barry Coombs - VMware FT
David Strebel - VMware Fault Tolerance Setup and Best Practices
Hany Michael - vSphere 4.0 Fault Tolerance (Architecture Diagram, Video and Use Cases)
Joep Piscaer - What I’ve learned from BC2961, “VMware Fault Tolerance Architecture and Performance”
Cody Bunch - Scheduling VMware’s FT (Fault Tolerance)
Rynardt Spies - VMware FT...Can you afford a SAN failure?
Roger Lund - VMware Fault Tolerance: What is it? What does it do?
Jason Boche - After enabling FT on a VM – subtleties to expect
Eric Sloof - Fault Tolerance at your home lab

The first round of the contest which features articles about Fault Tolerance is closed now. The next round “vNetwork Distributed Switch” will kick off next Monday. I just can’t wait for another round of great vNetwork articles in the coming two weeks. If you want to join the contest, don’t be shy and give John Troyer a heads up about your website.

You can establish fault tolerance for virtual machines hosted by ESX servers that are part of a VMware HA cluster. When you enable VMware FT for a virtual machine, an identical copy of the virtual machine, called a secondary, is established on another host in the cluster. If the first virtual machine fails, the secondary virtual machine takes the original one's place, and a new secondary is created. This process helps provide uninterrupted virtual machine functionality, even in the event of failures. Before you can enable VMware FT, you must have VMware HA enabled and the CPUs of the servers hosting the virtual machines must support VMware FT.

After publishing an article about the CPU compatibility with VMware Fault Tolerance, my search for a white CPU began. The vLockstep technology used by FT requires the physical processor extensions added to the latest processors from Intel and AMD. In order to run FT, a host must have an FT-capable processor, and both hosts running an FT VM pair must be in the same processor family.
Richard Garsthagen’s “CPU-Host-Info” shows all the available options on both the Intel Q9400 and Q9550 marked true. I’ve used the Intel Q8200 in another white box and it didn’t work, so in order to use FT, you need FT and both the VT options. The next step is run through the Fault Tolerance Checklist.

You can enable VMware Fault Tolerance through the vSphere Client.

Connect vSphere Client to vCenter Server.

Prerequisites 

The option to turn on Fault Tolerance is unavailable (grayed out) for a virtual machine to which any of the following conditions apply:
■  is not in an HA-enabled cluster
■  has one or more snapshots
■  is a template
■  is disconnected
■  resides on a host which is in maintenance or standby mode
■  is performing a record/replay operation

Procedure

1.  Select the Hosts & Clusters view.
2.  Right-click a virtual machine and select Turn Fault Tolerance On.

VMware Fault Tolerance requires eager zeroed thick disks. Virtual machines with thin provisioned or lazy zeroed disks must be powered off while enabling VMware Fault Tolerance in order for vCenter to complete this conversion.

The specified virtual machine is marked as a primary and a secondary is established on another host. Fault Tolerance is now enabled on 4 virtual machines :-)