Yesterday, Matt Fairbanks, VP Product Marketing, Citrix, and Jerry Melnick, CTO, Marathon, presented the webinar “Virtualizing Exchange – The Cold, Hard Numbers on Why Citrix XenServer + everRun VM is the Best Platform.” Below are a few of the questions asked from participants with Jerry’s response to each:

Q: What happens in a case of a split brain scenario?

Jerry: In our SplitSite products, we have what we call a quorum services capability – it’s actually an additional component that’s added on to manage split brain and arbitrate when you lose all connections between the two machines.

Q: How long does it generally take to set up XenServer with everRun VM to create this kind of a solution?

Jerry: Citrix people have always mentioned “Ten minutes to Xen” which is a pretty good rule of thumb. We say it’s another ten minutes to add the Marathon software. It’s a simple script that gets run on each host, and then you’re off and ready to protect the machines. The actual protection process itself is really a matter of a minute. The simplicity and ease have never been seen before in this industry with this class of availability solution.

Q: In field of limitations and customers that have deployed this kind of technology, are there any things you would council people to consider to set up XenServer and everRun in the most highly available and robust way?

Jerry: With our system, we provide best practice guidelines for configuring networks availability, etc. One of the beauties of our technology – working in conjunction with XenServer – is that once everything is installed and running, we put everything into an active validation mode so that we know components are configured properly. If something is misconfigured or isn’t running redundantly, you’re going to see the status and receive a warning. A key benefit of this system is you will know how to fix it before there are any problems.

There are many cases in availability systems where you have simple failover technologies: you take an error, you failover, you get to that resource, and then you find out the network or disk isn’t working because it wasn’t configured properly. By having this active validation capability and the report out, the status is being monitored in a simple and reliable fashion – you know when you’re redundant and how you’re going to manage failures.

Thanks to everyone that attended. For those that didn’t have the chance to attend or ask questions, please feel free to leave them in the comments section and we will do our best to answer them.

For those of you that may have forgot to put it on your calendars, Marathon and Citrix are holding a webinar today to showcase the benefits of virtualizing Microsoft Exchange servers. Event attendees will learn:

The webinar will begin promptly at 11:30 a.m. EDT, so if you haven’t yet registered you can do so here.

For those that can’t attend, we will be posting the Q&A following the event.

For most organizations, email is single-handedly the most important tool for accomplishing business objectives. Without access to email, companies are at an immediate disadvantage in today’s “I want it now” marketplace. For example, let’s look at the impact email downtime has on productivity: Assuming that your employees are 25% less productive when email is unavailable, and their annual salary is $60,000, then every hour of downtime for an organization of 500 people results in more than $7,200 in lost employee productivity. Can your organization bare a $7,200/hour loss? In today’s economy? Probably Definitely not.

Avoiding the aforementioned consequence is an option, but in order to do so you need to guarantee continuous availability for your organizations email server. According to Paul Rubens at ServerWatch, 2007 forecasts from Gartner revealed that Microsoft Exchange 2007 will own 70% of the email market share by 2010. Now, whether Microsoft will actually return those results, it’s still too early to tell. However, as more and more companies rely on Exchange servers to run business functions, all potential causes of unplanned downtime need to be identified and eliminated.

Over the next month, we will be providing you with some recommendations on how to improve Exchange high availability through planned and unplanned downtime – starting with a webinar on November 11 titled “Virtualizing Exchange – The Cold, Hard Numbers on Why Citrix XenServer and everRun VM is the Best Platform.” For this webinar, Jerry Melnick, Marathon CTO, and Matt Fairbanks, VP of Product Marketing for Citrix Virtualization and Management Division, will team up to discuss how the latest server virtualization technologies keep users continuously connected to Microsoft Exchange servers in the easiest and most effective manner. We encourage you to register online for the webinar if you haven’t already.

Is there anything in particular related to protecting your Exchange severs you would like us to address in the next few weeks? Leave us a comment below and we will be sure to put it on our radar.

Following last week’s XenServer HA announcement, we’ve been approached with questions like “How exactly does XenServer HA work?” and “How does XenServer HA and everRun VM work together.” Rather than respond ourselves we thought it would be best to point to a few fellow bloggers who have already answered these questions.

First, here’s a good post written by Anil Madhavapeddy at Citrix discussing how the overall architecture of XenServer HA works. Second, Scott Lowe has put together a great summary of why Citrix and Marathon worked together to develop XenServer HA.

If you want more details, please leave us a comment.

For those of you attending this year’s VMworld in Las Vegas, we will be demonstrating system-level fault tolerance for Citrix XenServer. This is what we refer to as level 3 on the availability dial.

If you’re interested please feel free to stop by our booth (#1047) to see it in action for yourself.

See you at the show!

As many of you may know, we will be attending virtualization.info’s Virtualization Congress 2008 in London, October 14-16. We highly recommend European IT executives attend the event to gain from vendors and peers lessons learned on planning, implementing, maintaining and maximizing virtualization investments.

Marathon CTO Jerry Melnick will be on hand at the event as a keynote speaker and will be discussing why the XenServer and everRun combination is so resilient. This won’t be the typical “marketing fluff” event you’re probably use to; instead presenters will be sharing real life case studies to illustrate how their products and services have helped deliver on the promises they’ve made to their customers. Additional keynote speakers of note include: virtualization.info founder, Alessandro Perilli, and Citrix CTO, Simon Crosby.

As a Gold Sponsor for the event, we have been given the privilege of providing our customers and business partners attending the event with a 25% discount for registration. To receive the discount simply visit the event registration page and enter the discount code: PartnersAtVC2008.

For those that have already signed up, Alessandro has made the event agenda available here. If you have any additional questions regarding our involvement in the Virtualization Congress or surrounding the event itself, don’t hesitate to contact us directly or leave a comment here on the blog. Hope to see you there!

A few week’s ago I wrote about virtualization in large enterprises – chronicling conversations I’ve had with Fortune 100 CEOs and CIOs. Following Jerry’s Mid-Market podcast, I thought I would chime in with my thoughts on virtualization in the Mid-Market; especially since the introduction of products like Hyper-V will increase mainstream adoption at the Mid-Market level significantly.

Mid-Market companies have completely different drivers for adopting virtualization than the larger companies. The key question for Mid-Market level CIOs is “can I consolidate everything?” Most large companies have the ability to segment out the applications they want to virtualize and allocate the appropriate staff to pull it off in a phased approach. Mid-Market companies lack that luxury. They are often times short staffed and have little resources to conduct this sort of deployment. And in many cases, if they can’t consolidate all of the apps, the return doesn’t pencil out.

Why haven’t more Mid-Market companies deployed server virtualization?

One of the first and foremost concerns on the mind of Mid-Market CIO’s I’ve talked to is that they want to be sure that they are going to be able to get and provide the same service as before. Keeping business critical applications like Exchange and SQL up and running, not only effects employees, but also customers and partners as well.

Another major concern which has prohibited Mid-Market companies from deploying is the idea that there are specialized skills required to maintain a virtual environment. This should not be a concern. While some virtualization platforms do require specialized IT skills, new platforms such as Citrix XenServer and Microsoft Hyper-V can realistically be deployed without an army of IT folks or a lot of specialized virtualization skills.

If you’re a Mid-Market company facing a virtualization hurdle, leave me a comment here. We would gladly dive-in to see if we can help you get over it.

“When we describe everRun VM to customers and prospects, the common reaction is ‘it’s too good to be true’” – Steve Keilen, VP of Marketing for Marathon Technologies

Today we made a Single Host Trial Edition of everRun VM available for prospects to download and test out. The trial edition allows users to experience everRun VM benefits – automated setup, configuration and management, intuitive interface and reliable VM protection – all within a matter of minutes.

By experiencing the simple “Click to Protect” power of everRun VM customers can:
• See how easy it is to protect a virtual machine in two minutes or less
• Put the protected VM through failure scenarios (including network and disk failures)
• Use online migration to move a running protected VM to another XenServer host

If you or your organization is in the market for fault-tolerant, high availability virtual server software, we encourage you to download the everRun VM Single Host Trial Edition. It comes with everything you need to get started, including an evaluation copy of XenServer Enterprise Edition. Feel free to leave a comment or contact us with any questions you may have.

Following last week’s discussion, event attendees had additional questions that we didn’t get to answer even though we went ten minutes over. We wanted to continue the discussion here on our blog so we figured we would post the continuation of questions and answers for everyone to see. As we mentioned before, if you would like to view the presentation delivered last week by John Humphrey’s (IDC), Simon Crosby (Citrix) and Jerry Melnick (Marathon), download the presentation here.

Are there any performance limitations with everRun VM?

everRun VM supports any guest environment created by XenServer, including multi-CPU VM’s.

Effect of losing inter-server link?

As a best practice we recommend two Availability Links for redundancy. If one should be lost, we will continue to operate unaffected using the remaining one. If both are lost we will take action to prevent complete loss of the VM or SplitBrain.

How far apart can the two machines be – i.e. is there a propagation delay issue?

Host separation is a factor of network latency, which must be <10ms round trip. Current deployments have exceeded 100 miles.

In case of a disk failure, does everRun rebuild the disk from the good physical host to the bad one?

Correct. Recovery of storage is handled as a background task so as not to require downtime or otherwise impact the running VM and application.

When will level 3 of everRun VM be available?

Level-3, System-Level fault tolerance is scheduled for later this year.

What requirements are associated with the everRun Level 3 Protection? (Bandwidth, latency, etc.)

Network and configuration requirements are the same for level-2 and level-3 protection.

Is StorServer a similar or competitive product to everRun?

StorServer is a backup appliance, not a fault-tolerant availability solution, and addresses very different requirements. It would be more complimentary then competitive.

What virtual machines (VMware, Parallel, etc) are supported by Marathon?

Currently only Citrix XenServer, however future plans are to expand upon this.

Are there certain applications that are not suited for everRun, such as I/O or compute intensive apps? Home does DR configurations affect performance?

This is very dependent on the configuration of the server, the VM, the storage and all other components. Appropriate best practices should be followed to ensure optimal performance for all applications.

Can Marathon support physical to vm HA? Does Marathon’s product fully support FC/iSCSI SAN shared storage between protected physical and/or vm pairs? Does Marathon product support local site HA server pair with a third node at a remote site in the event of site failure? Does Marathon product have latency limitations?

Marathon offers solutions for physical and virtual servers. These solutions utilize the same proven fault tolerant technologies however are independent of each other. everRun VM supports any type of storage that is supported by XenServer. Fault tolerance is configured using two VM’s. However we will soon be releasing an asynchronous solution that will allow a third replicated system at a local or remote site. Because everRun VM is a synchronous solution there is a latency requirement of 10ms round-trip between hosts. Our asynchronous solution will not have any latency requirements.

What is the pricing of everRun VM?

everRun VM lists at $4500 when bundled with XenServer Enterprise, and $2000 if you already have XenServer.

Thanks for all of your interest and questions.

There was a great turn out for the joint Citrix and Marathon Webinar today, The “Best of VMWorld Approach” to Virtualization and Availability. Thanks to everyone for attending. If you missed it or want more information visit here to download the presentation.

There were a lot of great questions for Simon Crosby and Jerry Melnick, which we have captured below. If anyone has any additional questions, feel free to leave a comment here on the blog or contact us directly.

Simon: Do you need 64-bit hardware to try out the express edition?

All modern server hardware is 64 bit enabled. Xen uses all of the modern features of Intel VT or ANDV to perform hardware virtualization of Windows; so the answer is yes but if you have a modern server you’re in good shape.

Jerry: How does everRun VM’s second level of availability differ from VMware HA?

One of the key pieces is that we compute through the failures of any I/O fault or failure, and then automatically redirect I/O to the device that survives it. In VMware HA, the failure of an I/O device isn’t necessarily detected or managed it’s just host failure. We are managing virtual machine failures in related I/O devices.

The second piece is that we’re doing active validation of all the devices so that we know at all times if all the resources are available and that they can actually be utilized in the case of recovery. If you don’t have active validation, such as with VMware HA, you can failover your VM and get to the other side but you may find that the device which handles the disk isn’t actually operational because of either a failure in the hardware or some kind of problem administratively with how you configured it.

Simon: Is there an extra cost associated with XenCenter?

No, it’s just a pre-feature of the product. Our architecture does not require something like virtual center because every server in the resource pool redundantly has every piece of information for the entire resource pool. Should any server fail, we automatically elect a pool leader from the remaining servers and all mainstream information is highly available as a result.

XenCenter itself is a perfect thin client UI which interfaces with as many resource pools as you want to run, but it is literally a thin UI – it’s stateless, and all of the state related to managing the infrastructure is in the infrastructure itself, which allows us to really scale this architecture.

Jerry: In the demonstration you gave, are users hitting both hosts in the exchange application being protected?

In the level 3 fault tolerance configuration we are running both hosts redundantly which is what you need to do for full system-level fault tolerance. In level 2 the amount of resource being utilized is less because you’re actually only running a virtual machine on one of the hosts, but you’re running I/O on both of the hosts. In level one you’re running at the next level down, with only a single VM allocated and no preallocation of the secondary side, with all I/O processing on just that one side. There is no active redundancy. That’s why we provide the different levels; so that you can choose which virtual machines really need to use that resource and have that ability, and which ones you want to make some trade-offs of availability versus resource utilization.

Simon: What does it mean to have a 64-bit hypervisor and why is that better?

If you have a 64-bit hypervisor then you can host both 32 and 64-bit guests and you don’t have any issues really to address space conversion problems. It’s a cleaner architecture, the memory architecture scales massively up to four terabytes (not that you can buy a server that has four terabytes of thin slots), but it allows us to massively scale the memory and CPU of the system. We support up to 32 physical CPUs and a box as a result, and we have an architecture that is going to scale superbly for us.

Jerry: Do you need a dedicated LAN to run everRun VM?

The only dedicated LAN we use, and can actually be shared because of the flexibility of XenServer itself, is what we call the availability link which is part of our best practices. Otherwise it’s all a standard LAN configuration that you would have in the XenServer pool.

Jerry: Are there certain applications that are not suited for everRun?

Our technology is completely transparent – relative to the application itself. Any windows application that you run on a Windows VM can be run by our technology.

Jerry: Is it possible to combine XenMotion with everRun VM?

As part of our capability, the ability of motion of VM from one host to the next is extremely integral to it. You get the capabilities to provide recovery from failures as well as to be able to have planned downtime and migrate your VMs when you want to do a repair. It’s an integral part of the product and we use XenMotion as the backbone of it. One difference with everRun VM is that we allow this motion capability without the need for a shared-LUN, or SAN, storage subsystem.

Simon: How would a current ESX 3.x customer migrate to a Xen environment and why should they do that?

There are free tools available to do this which can be downloaded off our forums and indeed Microsoft has similar free tools available. Here’s why you would do it: we guarantee that Citrix XenServer VMs are literally compatible with Microsoft Hyper-V. They’re also compatible with every other Xen implementation. What I see emerging is essentially two camps: A camp in which there is an open architecture (Microsoft storage architecture is very similar to XenServer, it’s also an open architecture) where you’ll have a bunch of virtual infrastructures out there from different vendors all of which are interoperable; and then a camp where there’s VMware.

The reason to move to XenServer is that we are fundamentally focused on a rich ecosystem of value added providers. We are diametrically opposed to an architecture which presumes that everything comes from one vendor, and where the entire architecture is dictated to you. The moment you invest in an architecture which is one size fits all (cost aside) you will find that it has limitations.

I am starting to see that the one size fits all architecture, which has done VMware a great favor for its first 10-15% of the market, is starting to show signs of age as we look at new use cases. For example, for desktop virtualization or for high availability, you can’t do this with that architecture and its no surprise then that at VMWorld the awards for innovation go to open architecture and best of breed vendors – Marathon at VMWorld winning the award for fault tolerance. We are dedicated to an open architecture and best of breed.

Jerry: Is Marathon planning to protect Linux based VMs in the near future?

Our road map will extend over the next year to protect all the hosts that are supported by XenServer.

Simon: Can you give a rough idea of the performance overhead of a virtual server vs. a real server?

It’s highly dependent on the workload. Typically we see between .5% and 2% overhead even for very I/O intensive workloads. For Windows it’s notionally higher. The great thing about this is that we are writing the hardware code; unlike my friends at VMware who are still tied to software implementation of virtualization in which they have to patch the binary of a running guest operating system. We ride the hardware improvement curve of Intel and AMD. What we’ve seen there is roughly a three-fold performance increase per year. Typical overheard for virtualizing Windows guests is around 3-5%. The most intensive workload I have ever seen is in fact Windows Terminal Services or our own Citrix Presentation Server where we currently stand at about 8% overhead.

Jerry: Does everRun VM support shared storage?

Yes. We actually support any capability in storage. Whatever kind of LUN that you can present to XenServer and carve up into a storage repository or a VHD, we will support that. If it’s a local disk, low-end RAID storage or just a bunch of disks we will support that, as well as high-end SAN storage. The advantage of the product is that we will support local storage for very low-end small environments.

Jerry: How far can the servers be separated?

It is not a matter of actual distance but rather a matter of network connectivity between the two hosts. We have systems currently deployed with separation of greater than 100 miles.