Stephanie Balaouras, Principal Analyst at Forrester Research, has an interesting blog post this week on ZDnet about the increasing interest in high availability from her clients. In her article “How Do We Measure High Availability?” she makes several key points:
As companies become 24X7 “always on” operating environments, they are becoming more and more sensitive to application and system downtime.
HA is no longer an all or nothing discussion about proprietary fault-tolerant systems or high-end clustering solutions. Today there are lower-cost alternatives that provide the required level of availability at a cost justified by the risk and cost of downtime.
Developing and agreeing upon SLAs is the toughest part of HA planning, but these KPIs are good starting point toward metrics that matter to the business.
Earlier this year, we spoke with Stephanie about the topic of virtualization and high availability. You can read that Q&A here. For additional info on this topic, you can also download Forrester's recent white paper "X86 Server Virtualization For High Availability And Disaster Recovery."
We had a number of questions during the Q&A session of our June 24th webinar with Stephen Wynkoop, founder of SSWUG.org. I’ve posted the questions and responses here on our blog for everyone’s benefit. This webinar was recorded in case you weren’t able to attend, click here to view the webcast!
Q: Does everRun require a SAN? A: It doesn’t require a SAN. We can also mirror storage between two different systems, if that’s what you chose to do. A lot of our customers do that, either locally or separated geographically. We can support a SAN in multiple ways. We can support a SAN where you have a single copy of the data. And both servers will connect too the single copy of the data. We also support a SAN where one of the servers is connected to that SAN and the other server has its own storage and we can mirror between that. A lot of our customers are using that option to provide data protection and fault tolerance at the data level. We can use different types of storage on either side.
Q: With your SplitSite product, are there distance requirements?
A: There are no pre-determined distance limitations – it’s really the latency and bandwidth requirements that determine the distance that can be supported.
Q Does everRun work with Exchange 2007 as well?
A: Yes it does. everRun supports any Windows application without requiring changes or customization.
Q: Does everRun work with iSCSI?
A: We have an agnostic approach to storage as well. Pretty much any type of storage will work. iSCSI, fiber, direct attached, etc.
Q: What are the requirements between the paired local servers?
A: A gigabit Ethernet connection with crossover cables is usually used between the two servers.
Q: What is the performance impact of using everRun with SQL?
A: Our preliminary testing has shown that the overhead is very small. There are variance rates depending on the servers and applications that you are using, but the impact has in general been shown to be very small.
Q: How does everRun handle the mirroring of data that’s loaded in the memory?
A: With our level 3 fault tolerance, we actually mirror the memory and CPU between the two systems, so they are running in lockstep. This provides a 100% uptime solution. Our everRun software makes sure that the memory and CPU state are mirrored and completely synchronized between the two servers at all times.
Q: Does everRun work with SQL 2008?
A: Yes. everRun supports any Windows application without requiring changes or customization. Because everRun resides below the operating environment, we are protected underneath that. We have a number of ISVs that use our software with their applications and they use us because they don’t have to make any changes to their software. It’s not tied into the application, and doesn’t need to be “cluster aware” or anything similar to that.
Q: Does everRun work with the free XenServer?
A: Yes, everRun VM for XenServer supports the free version of XenServer as well as Essentials for XenServer Enterprise and Platinum Editions.
Q: How would you tackle a shift from a single server to an everRun setup to have minimal downtime during the changeover?
A: It’s pretty straight forward. You could buy new servers if you wanted to refresh your hardware. Then you would perform a P2V migration. There are tools like PlateSpin to help you do that. It’s a standard migration process. If you wanted to use your existing server, you could buy one additional server and pair those up. We also offer migration services if you want additional help with the process.
Q: If using everRun with SQL Server, is the secondary server available for query/reports by other processes?
A: It‘s not because the two SQL environments have the same identity and exposed to the network as just a single server instance. Since they both have the same identity,you can’t access one by its production identity and then the other. They look and act as a single environment. They have the same MAC address, host name, and IP address. If you make a change, it happens to both of them.
Q: In a SplitSite implementation, if one hardware platform fails and the backup is used, how is the data re-synchronized once the primary hardware is available again?
A: everRun is completely automated, including the recovery process. When you have a failure and get that system back online, everRun will automatically synchronize the two systems to be identical again. There’s no additional work to do the syncing, it’s completely automated.
Bhumik Patel of Citrix has posted Part II of the Citrix and Marathon demo at SAP on his blog. Part I of Bhumik’s blog series looked at specific details on Citrix Delivery Center and the Disaster Recovery demonstration for SAP NetWeaver.
Part II covers different high availability solutions also demonstrated at SAP. In addition to this blog series, a Reference Architecture document provides all the technical details about Citrix and Marathon solutions implemented for SAP. When looking for an HA solution, various factors such as application criticality and business impact must be considered before choosing a particular solution for an application. A more detailed report on determining availability requirements can be found here.
The following video from Citrix features the Marathon everRun VM Level 3 High Availability solution demonstrated at SAP Co-Innovation Labs in Palo Alto.
Analyst firm The 451 Group has just released some very interesting findings about virtualization and availability in a recent report by Chief Analyst John Abbott. Some of the key take-aways include:
• Virtual infrastructure can form the basis of fully automated availability processes. Availability becomes a default property of the virtual machine.
• ‘Dial up’ levels of availability can be implemented, depending on the requirements of specific applications or departments.
• If a system restore is required after a disaster, it’s usually much easier and much quicker to restore a virtual machine than a physical machine.
• Virtualization infrastructure is already a core component in datacenter automation, unified computing (the bringing together of servers, storage and networking) and cloud computing. Availability services based on top of a virtualization layer will slot right into any of these longer-term initiatives that customers may be working toward.
• Industrial-strength storage networks, currently a best-practice requirement for virtual availability, will lose ground to alternatives, which are maturing.
• The worlds of high availability and disaster recovery are coming together as virtualization is added to the mix.
• Tools more friendly to end users are likely to emerge, reducing the load on enterprise IT support staff, but requiring sophisticated underlay technology.
One of the promises of server virtualization is improved high availability and more efficient disaster recovery. But according to the Enterprise Strategy Group (ESG) to achieve these goals with virtualization requires the modification of existing processes. It also requires looking beyond the virtualization vendor's HA and DR products to achieve SLAs for all workloads.
Mark Bowker and Lauren Whitehouse, analysts from ESG, recently put together an exclusive report on this topic called “Business Resilience in Virtual Environments” that explores:
• The advantages and challenges of server virtualization for improved business resiliency
• The limitations of the virtualization platform vendor's offerings for HA and DR
• Misconceptions about common business resiliency terms such as high availability, fault tolerance and disaster recovery
• How to use a combination of third-party solutions and new processes such as V2V, P2V, V2P and V2C to meet your application SLAs and DR objectives
This report is available exclusively from Marathon. You can download a copy here.
Getting ready to deploy Exchange 2007? If so, we’ve put together a comprehensive set of tools to help you select the optimal availability levels for your Exchange 2007 environment:
• Optimizing Exchange High Availability—A New Approach explains how to use a new strategy for Exchange high availability that enables you to protect all aspects of your Exchange environment with the right amount of resources.
• Exchange 2007 Performance White Paper to help you understand and characterize the performance implications for running Exchange 2007 with everRun.
• Exchange 2007 Deployment Blueprint that includes hardware recommendations, workload planning, shared storage design, networking best practices and other practical tips for your Exchange 2007 deployment with everRun.
• Webinar/Q&A: download our “Optimizing Exchange High Availability” webinar and also check out our blog post that recaps the Q&A covered during the webinar.
Protecting SQL Server and its related applications continues to be one of the most common concerns we hear from our customers. With that in mind, we’ve pulled together some SQL-related info and links for your reference below.
While you’re here, be sure to sign up for our free June 24th webinar “SQL Availability: Protecting Your Database and Applications”. The featured speaker will be SQL MVP Stephen Wynkoop, founder and editor of the SSWUG.com website and user group.
We recently teamed up with Citrix to demonstrate an end-to-end Citrix and Marathon combined solution onsite at one of the world's largest business software companies, SAP. Bhumik Patel of Citrix was one of the team members on the project.
A quick overview of the project is available here.
First they virtualized every Citrix Delivery Center component and the backend SAP NetWeaver application servers using Citrix XenServer. Then they showcased what a remote SAP NetWeaver user would experience accessing the SAP NetWeaver Portal via Citrix Delivery Center while focusing on the high availability/fault tolerant solutions Citrix and Marathon provide. Finally, they simulated a complete failure in the primary site and used the combined NetScaler Global Server Load Balancing feature in conjunction with Marathon's everRun DR product to failover SAP to a secondary data center.
Each piece of the demo is broken down into small video segments in Bhumik’s blog. Part One is available now. Stay tuned to Bhumik’s blog for a detailed reference architecture and additional videos on different high availability scenarios including everRun VM, also demonstrated at SAP Co-Innovation Lab.
We had some great questions during the Q & A session of our May 20th webinar with myself, Michael Bilancieri, along with Tom Reed here at Marathon. I’ve posted the questions and responses here on our blog for everyone’s benefit. This webinar was recorded in case you weren’t able to attend, click here to view the webcast!
Q: Does everRun work on all XenServer versions?
A: Yes, everRun VM for XenServer supports the free version of XenServer as well as Essentials for XenServer Enterprise and Platinum Editions.
Q: When there is geographic diversity - what level of protection is reasonable?
A: This depends on the distance between the two sites and the network connecting them. For metro or regional separation (campus, across town, etc.) everRun fault tolerance can be implemented to provide resiliency to hardware and site failures. For longer distances or between sites that have slower/smaller networks, a disaster recovery solution may be appropriate. Disaster recovery typically involves asynchronous replication and failover capabilities.
Q: What amount of bandwidth is required between the main site and the disaster site?
A: This is going to vary depending on workloads protected and how high the activity level is. Higher activity requires higher bandwidth. At a minimum 150Mb is required.
Q: Can everRun be used in a remote location situation where there is geographic diversity for DR capabilities?
A: Yes. However this dependent on where your DR site is located in relation to your main site (metropolitan/campus wide vs. cross-country).
Q: Are there vLAN dependencies for SplitSite for Exchange? A: A common subnet is required between the two locations. A vLAN would work fine.
Q: Are you currently developing for Exchange 2010?
A: everRun supports any Windows application without requiring changes or customization. Exchange 2010 should not add any additional requirements to everRun and should be seamlessly supported..
Q: Are there minimum requirements for ISCSI or fiber SAN?
A: We are storage agnostic and we don’t require shared storage or have specific requirements for storage connectivity. However There are some best practices that will help to ensure optimal performance. These can be found in our advanced concept guide, available on our website.
Q: Do you have a solution for SMB that works in the 50 user range?
A: Yes. Our everRun solution will work with any version of windows 2003 or 2008, 64-bit or 32-bit. We work for small scale solutions all the way up to enterprises.
Q: Can this be used with VMware as well? A: Not at this time.
Q: Do you also support Exchange 2003?
A: Yes. We support Exchange Windows 2003 and 2007. everRun supports any application running on Windows Server 2003 and 2008.
Q: Do you work with other applications? A: Our architecture sits underneath the operating environment, not at the application level, which allows us to support any and all Windows applications without changes or customization.
We had a great time at the Citrix Synergy show in Las Vegas a couple of weeks ago. Citrix put together a well-organized show that facilitated some good discussions with our partners and customers. Overall the show was a great success for us.
We also had some fun at the show going on camera with “Citrix TV” to talk about how our everRun products protect XenServer applications and virtual machines as well as provide fault tolerance for XenApp. You can watch the interviews with Jerry Melnick, Tom Reed and me below.
Given Citrix XenApp’s increasing importance to many organizations, Marathon has put together a XenApp High Availability Tool Kit to provide you with the information you need to achieve your SLA commitments:
• Optimizing Citrix XenApp High Availability white paper explains how to use a new strategy for XenApp availability that enables you to protect all aspects of your XenApp environment with the right amount of resources.
• XenApp 5.0 Deployment Blueprint which includes server recommendations, workload planning, shared storage, network best practices and other practical tips for your Citrix XenApp deployment with everRun.
Also, be sure to check out this video from Gabe Carrejo, a technology specialist at Citrix, which provides a demonstration of how to achieve high availability for Xen virtual servers with Marathon.
Dan Kusnetzky from ZDnet has a great post on his blog today about The Sullivan Group, a Human Resources Outsourcing (HRO) company (and Marathon customer) based in Savannah, Georgia. Erika Simpson, Network Administrator, and Rob Jones, IT Director, at The Sullivan Group, gave some great advice that can be applied to almost any IT implementation. Here’s what they suggest:
• Having a powerful enough infrastructure is something to focus on. Although the economy is tight, it is worth acquiring sufficient hardware and software resources to test applications before deploying. They are happy that they selected 64-bit industry standard systems as a platform because it has offered more than enough performance to handle their workloads.
• Test until you can’t test any more. This will allow you to make mistakes, learn from them and yet not have a negative impact on customers and their data.
• Read the instructions. If you don’t understand the instructions look for help from the vendor, from blogs, from forums and if all else fails, Google it!
Since implementing Citrix XenServer and Marathon’s everRun VM, which The Sullivan Group is now leveraging to protect their Microsoft Dynamics-based SamWare applications, the company has had zero downtime, even during a significant failure.
You can read the full article on the ZDnet Virtually Speaking blog here.
I recently blogged about how to apply the three levels of availability to Exchange 2007 mailbox servers. By splitting the amount of users across multiple VM’s you can provide a level of availability to each set of users based upon your SLA with each business unit in your company.
Since Exchange is more than just a mailbox server, we thought it would make sense to provide you with a deeper look at how to protect all of the components of your Exchange environment. I’ll be co-hosting a webinar on this topic on May 20th. You can register for this webinar here. We'll provide an in-depth look at a new approach that allows you to tailor the levels of availability by user groups and Exchange components.
We’ve also published a new whitepaper on this topic, “Optimizing Exchange High Availability—A New Approach,” which is available for download in our Resource Center.
We received over a hundred questions during the Q & A session of our April 29th webinar where we covered our new everRun technology. I've posted the questions and respondes here for everyone's benefit.
Q: Level 3 will support 2 Socket Processors? A: A level-3 protected workload must be single-CPU configurations. With the ability to now support multiple workloads with everRun 2G, multiple single-CPU workloads can be protected at level-3 on the same pair of servers, allowing utilization of multi-processor systems.
Q: How does everRun handle custom application? From the answer, it only has to be on 1 machine then everRun will handle the redundancy for the second machine?
A: everRun runs below the operating system which enables it to support any Windows application without any customization. everRun automatically mirrors the entire workload to a second system and maintains redundancy in a synchronous manner.
Q: For Level 2 and 3 protection, does the application (Exchange, SQL, etc) have to be installed on both servers (in your example, everRun1 and everRun2)?
A: everRun automatically mirrors the entire operating environment, including the OS, application, and data, to a second system. This eliminates the need to manually install and maintain the OS and application a second time.
Q: Please define a "workload"
A: A workload is a complete and independent operating environment, consisting of its own OS, applications, etc.
Q: What is difference from the last generation product? Also, is 2G just an upgrade or is it a completely different product than HA and FT?
A: everRun 2G is the next generation product following everRun HA and FT yet it is not an upgrade to HA and FT. It is a separate product that requires a new installation. everRun 2G is designed on a completely new base platform, utilizing Xen rather than Windows as is used by HA & FT. This design provides improved flexibility, scalability, and ease of use and management. One of the major advantages of this new design is the ability to create and protect multiple workloads on the same pair of physical servers.
Q: What about copy protected applications that use hardware serial numbers for activation?
A: For applications that use hardware-based license keys, such as a dongle, please contact Marathon to discuss the specific details of your application.
Q: Do you offer support? online? 24/7?
A: everRun solutions include 1st-year maintenance which includes 24/7 technical support (online, email, phone) as well as product updates.
Q: Can the physical server / host server be considered as a workload?
A: We don’t refer to the physical host as a workload. However additional workloads can be created on the physical hosts. These workloads do not need to be protected/cloned by everRun. You have the choice of protecting them or not.
Q: Is it also possible to use NAS technology instead of SAN storage? A: Certainly. Any type of storage can be used on either host, and one huge advantage of everRun is that these do not need to be the same. One host can have NAS while the other host has locally-attached storage.
Q: Can everRun be used to keep 1 host running for the end-users while the application on the other host is being upgraded?
A: Yes, one side of the protected environment can be taken offline for upgrades and testing while the other side remains online servicing clients.
Q: What are the bandwidth requirements when I run 2 hosts over a WAN?
A: 150mb connection with a maximum latency of 10ms roundtrip between the two hosts.
Q: Can everRun protect against OS failures?
A: With level-2 protection, an OS failure will result in a restart of the application environment. With level-3 protection, the result will vary depending on the cause of the failure. If the application causes a bugcheck within the OS, this will happen on both systems and the OS will restart. If the failure is caused by faulty hardware the OS and application will continue to run on the paired system without interruption.
Q: What happens if WAN-line fails?
A: Communication failures between the two hosts will result in one of the systems taking itself offline to prevent a split-brain scenario. everRun utilizes a quorum service to negotiate which system is to remain online and which is not. When the failure is rectified, everRun will automatically synchronize the systems to regain full redundancy.
Q: How many hosts can be supported in the config?
A: Currently we have tested up to 4 hosts in a single pool.
Q: Can these network adapters be bonded at the OS level? Meaning I get a level of local redundancy as well before failing over traffic to another system.
A: Yes
Q: What host OS does this solution run on? A: Citrix XenServer
Q: How does this product compete or work with technologies like VMware or Hyper-V? esp Hyper-V R2.
A: Marathon has recently announced a joint development effort with Microsoft to provide fault tolerance within a future release of Hyper-V. VMware is not currently supported by everRun.
Q: In a FT configuration, what is the system resource overhead? is this on a system wide, or per workload (i.e. VM and app) which are configured for FT?
A:Overhead varies depending on the hardware and the actual applications. We have tested various applications including SQL Server, Exchange, and XenApp and found CPU overhead to be anywhere between 3% to 14% over a non-protected workload. This information is available on the Marathon website under the Solutions section for Exchange and XenApp. SQL Server will be available soon. We are in the process of quantifying overhead with level-3.
Q: At what interval do you monitor the standby components? And is this different than the online/active components?
A: everRun is constantly monitoring all active and standby components to ensure any failure is identified so that it can be rectified. This is one of the major differences in the everRun architecture. Typical availability systems don’t monitor the health of the standby system and components. If one of these should fail without notification, a failure on the active system will result in the system not being able to recover.
Q: Can you use hardware capabilities? Such as replication?
A: everRun offers two different storage protection options; everRun mirrored storage in which everRun mirrors all data between the two hosts for full fault tolerance at the storage level, and also supports a shared-LUN model wherein there is just a single copy of the data which both systems can access. When a shared-LUN model is used everRun does not protect the data and assumes that the storage subsystem has been configured to cover this.
Q: Does it sync memory pages and system registers, etc. - so the OS/App is running on both nodes in lock step?
A:Yes
Q: What are levels of protection? What criteria defines each level? Level 1 requires shared storage? Level 2 - mirroring/replication? Level 3 - FT?? Please clarify.
A: Check out The Three Levels of Availability Whitepaper, as well as a breakdown here:
Level-1 protection provides basic failover of workloads when a host fails. There is no redundancy maintained so if resources are not available on other hosts to restart the workload, it will not be restarted. Level-1 does require shared-storage/shared-LUN.
Level-2 provides fault tolerance at the storage, data, and network levels, meaning that a failure in those areas will not impact the application. A complete system failure will result in the application being restarted on the secondary host. The entire workload is mirrored to the secondary host with memory, CPU, storage, and networks allocated to ensure it can restart if necessary. Level-2 supports separate storage on each host or a single shared-storage configuration
Level-3 provides full system-level fault tolerance, meaning that the application will remain running without interruption during component and even complete system failures. Level-3 also supports separate storage as well as a shared-storage configuration.
Q: Is there a limitation on the number of processors for the VM or Physical Processors? I heard that ESX has a limit of one VM for their proposed Virtual Cluster in VM4.x
A: Level-2 component –level fault tolerance can support workloads up to 8 vCPU’s. Level-3 system-level fault tolerance supports 1 vCPU.
Q: If we have an application that is licensed per CPU socket, how will that be licensed since it sounds like it will be running on two separate servers now?
A: Licensing requirements vary by application vendor. Please contact your Marathon reseller or Marathon directly to discuss your specific applications.
Q: With the newer version of Marathon, is there network improvements where the software can be used with a smaller network bandwidth?
A: everRun 2G has the same latency bandwidth requirements as everRun HA and everRun FT.
Q: If we have an application that uses 4 Gbytes RAM and normally use Windows Server 2003 Sandard Edition. If we have 3 workloads (total of 12 Gbytes), the servers must have (for example) Windows Server 2003 Enterprise Edition.
A: Each workload has its own instance of Windows OS and is limited by the amount of RAM within each specific workload, not the amount of RAM on the physical host. Enterprise edition offers some licensing concessions when used in this environment which may help to save on Windows licensing costs.
Q: When will the software be released?
A: May 18, 2009
Q: What is the maximum number of workloads that can be run?
A: There is no hard limit configured into everRun. The number of workloads will be dependent on the hardware and the applications being run.
Q: Do each of our workstations need to have Windows 2003 Enterprise installed or can continue to use Windows 2003 Standard Edition?
A: everRun does not require Windows Enterprise edition. Windows Standard edition is support as well.
Q: Does this work with VMs with multiple processors?
A: Yes, depending on the level of protection desired.
Q: What are the specifications in terms of bandwidth and latency for level 3 ft? can this go over the WAN? Site to site? A: Site-to-site is what Marathon refers to as SplitSite. This capability is available for level-2 and level-3 protection. Bandwidth required is 150mb with latency of 10ms or less roundtrip.
Q: What happens if a protected VM bluescreens or stops functioning?
A: This depends on the level of protection and the cause of the bluescreen. With level-2 protection, the application will be restarted. With level-3, if the bluescreen is caused by a software issue within the OS or application, then both sides of the protected environment will bluescreen and the system will restart. If the bluescreen is caused by a hardware issue (faulty memory, etc.) the second side will not be affected.
Q: What version of XenServer does this work with? The newest free version, or essentials only? 5.1 u3? 5.5?
A: This latest release of everRun availability on May 18 will support XenServer 5.0 Update 3. It will fully support all versions including Free and the Essentials packs.
Q: Did the db server get affected by exchange server failure demo?
A: No. The database server is a completely separate workload and was not affected by the failures that I invoked on the Exchange server. Throughout the entire demo as failures were introduced, both the Exchange server and database server remained active and available, as was shown by the use of LoadSIM.
Q: What OS does it support?
A: Windows Server 2003 Standard and Enterprise, 32-bit and 64-bit , as well as Windows Server 2008 64-bit.
Q: Is there limits to rolling upgrade method?
A: Please contact Marathon to provide further details on your question so we can be sure provide the correct answer. Contact us via email or call 888-682-1142.
Q: What is the distance limit for latency support between hosts?
A: Distance is a factor of latency of the specific network being utilized. We have customers running at distances of over 100 miles between the two everRun systems.
Q: Are you considering a version that will replace the Microsoft Windows OS? This would remove a level of security support and target only Marathon for security.
A: No. Marathon does not build operating systems.
Q: Is there a performance graph during failures?
A: Results of our performance tests can be found on our website under the Solutions section.
Q: Do you have rolling upgrade support?
A: Yes
Q: Is VMWare supported?
A: No
Q: How much hardware similarities must exist between hosts in pool?
A: Same make and family processor
Q: Do u install everRun inside XenServer? Or is it a seperate server?
A: everRun installs on top of XenServer.
Q: Does it support Linux VMs? A: Level-1 protection supports Linux. Level-2 and level-3 do not at this time.
Q: Does level 3 protection require shared storage?
A: No. Both level-2 and level-3 can mirror data between hosts using similar or dissimilar storage, as well as supportinga shared-storage/shared-LUN configuration wherein everRun does not mirror the data.
Q: When will Lunix be supported? A: A data for Linux support has not been defined.
Q: Support on a mac environment with virtualization?
A: No
Q: If you lose Adapter 0 in everRun1 and Disk 0 in everRun2 would things still run?
A: Yes. All workloads would continue to run uninterrupted as if nothing has happened. everRun masks the failures from the application.
Q: If you set up a server as a level3 and realize you need additional processors can you roll back to a level2 protection?
A: Yes, you can easily change levels of protect via the protection wizard.
Q: Will level 2 mirror data as well so if you are running on host1 and a failover occurs and you come up on host2 you will have essentially the same data as when host1 went down?
A: Yes
Q: For level 2 for Exchange will Mx-records be an issue? Same question for level 3 A: No. The all everRun protected workloads have a single IP and MAC address, regardless of which host the application workload may be active on. This eliminates the need to make DNS or MX-record changes, allowing immediate redirection of network I/O to the second host without interruption.
Q: Does 2G support Windows Server 2000, 2000 Advanced Server?
A: No
Q: What do you consider a Virtual Machine? You use that terminology, is that a function of your software or other virtualization products such as VMWare
A: A virtual machine, or workload, or guest refer to the same thing. It is a complete and independent operating environment. In everRun 2G, everRun utilizes XenServer to create and manage these while everRun provides fault tolerant protection to them.
Q: What performance enhancement/degradation has been seen in testing with 2G over no FT/HA solution and also over previous releases?
A: Initial tests have shown similar and even improved performance over everRun HA and FT.
We’re in the running for the 2009 Citrix Ready Solution of the Year award. The winner will be announced next week’s Citrix Synergy event in Las Vegas. If you’re attending Synergy, be sure to stop by the Marathon booth (#414) for a live demo of everRun VM.
Citrix and Marathon have been working together since 2007 to broaden the adoption of both virtualization and high availability software. everRun provides completely automated fault-tolerant, high availability for Citrix XenServerand Citrix XenApp.
We’re honored to be among the six finalists who were selected based on their impact on Citrix business, commitment to its relationship with Citrix, customer satisfaction, channel and field commitment, and marketing commitment.
We had an incredible amount of great questions during the Q & A session of our April 16th webinar with myself, Michael Bilancieri, along with John Humphreys of Citrix Systems and Doug Strain of HP. I’ve posted the questions and responses here on our blow for everyone’s benefit. This webinar was recorded in case you weren’t able to attend, click here to view the webcast!
Q: Is everRun VM ready to work with free of charge XenServer?
A: The new version of everRun VM software (available mid-May) works with the new free enterprise-ready version of Citrix XenServer as well as Citrix Essentials.
Q: Is a SAN required to implement these fault tolerant solutions?
A: No, SAN is not required, but is certainly supported.
Q: How is everRun VM licensed?
A: everRun VM is licensed per XenServer host for level 2 protection, with level 3 protection being licensed per each VM you wish to protect with complete system-level fault tolerance.
Q: How much does the license for everRun cost? Where do I go for everRun Pricing?
A: Pricing for everRun VM starts at $3000 per XenServer host. For more information, please contact Marathon Sales Department at 888-682-1142 or info@marathontechnologies.com , or contact your Marathon reseller.
Q: How does everRun synchronize, and how often?
A: everRun VM performs an initial mirror of the entire VM upon protecting it and continuously mirrors it in a synchronous manner to ensure that the two paired systems are always identical.
Q: What are the overheads CPU, memory, and bandwidth for running everRun?
A: Overhead varies depending on the hardware, storage, applications and load. We will have performance data available shortly that shows the variance between a standalone VM and one that is protected with everRun.
Q: To summarize Marathon Technologies’ solution, is it replication of VMs between two VM Hosts? How much resource does this take away from VMs / VM Host?
A: everRun is not a replication technology, but rather a fault tolerant solution that offers the ability to synchronously mirror the entire VM between two physical XenServer hosts. Should one host suffer a component or even system failure, everRun VM allows the application to continue running without interruption. Here is a flash demo that explains how everRun VM works. Overhead varies depending on hardware, resources, and application load. We are currently benchmarking performance characteristics and should have them available within the next few weeks.
Q: Does the restart disconnect users connected?
A: For most hardware failures, there is no restart. everRun VM simply redirect I/O (storage and network) to the secondary host. If level 2 protection is utilized and a host is powered off, there is a brief interruption while the VM is restarted on the secondary host. With level 3 protection, there is no interruption even when a host is powered off.
Q: How many servers can you have in a pool?
A: everRun VM is qualified for up to 4 XenServer hosts in a single pool.
Q: Does everRun provide offsite datacenters which host VMs? Or do they offer software, or both?
A: everRun is a software solution that mirrors the entire VM to a secondary XenServer host either locally or at a remote location. We do not offer hosting services.
Q: Does Citrix FT/HA need shared storage?
A: There are three levels of protection available within everRun VM; levels 1, 2, & 3. Level 1, XenServer HA, is included as part of Essentials for XenServer and does require shared storage. everRun adds level 2 and level 3 fault tolerant capabilities and allows the option of using shared storage or independent storage between which everRun will synchronously mirror the entire virtual machine and all its data.
Q: Any migration tools off VMware?
A: There are a number of migration tools that can perform virtual-to-virtual (V2V) migrations from VMware to Citrix XenServer where they can then be protected by everRun VM. Please contact Citrix or Marathon for further details.
Q: Does Geographic Fault Tolerance require the two servers to be on the same subnet or can they be across routed networks?
A: Yes, the servers within an everRun configuration must be in the same subnet or on a common vLAN.
Q: What is the support for Windows Server 2008 timeframe?
A: The new version of everRun VM (available mid-May) will support Windows Server 2008.
Q: Does Marathon’s product protect SMP VM’s, or just single processor VM’s?
A: everRun can support multi-processor VM’s.
Q: With everRun, is it possible to sync VM’s across a WAN without SAN block replication? ie: local storage to local storage?
A: Yes, everRun will mirror the entire VM, including OS, application, and data, between two XenServer hosts with separate storage. These two systems are kept synchronized continuously.
Q: We have a custom application we currently run on a MS active/passive cluster. One of the useful things is we can update the code on the passive node, flip to it and if there is any issue, easily flip back to the original node. Is there a way to do this with everRun? ie: “pause” the sync and flip which is active VM?
A: For upgrades, everRun allows one side of the pair to be taken offline for applying and testing upgrades before applying them to the live running system.
Q: Is everRun part of Essentials, or is this a different product add-on? Does it require Essentials or just the hypervisor if it’s an add-on?
A: everRun is a separate product from Marathon Technologies and is not included in the Essentials offerings. everRun does support the Essentials offerings as well as the free edition of XenServer. everRun is simply installed on top of XenServer.
Q: Can you confirm that Marathon HA is an existing part of Citrix Essentials?
A: everRun VM is not bundled with Citrix Essentials for XenServer, however it can easily be installed on an Essentials deployment. Citrix Essentials for XenServer does include level 1 or auto-restart HA (XenServer HA) which was jointly developed by Marathon and Citrix.
Q: I have a question about switching virtual IP or domain name to the remote standby site in case any disaster happens to the primary site. Is this handled automatically without human interference? How is DNS cache updated in the domain name servers across the world?
A: everRun VM is a synchronous solution and as such has fairly stringent requirements for network latency. everRun VM is not a DR solution that can protect systems across thousands of miles, but rather a disaster tolerant solution that allows regional or metropolitan separation. The XenServer hosts being used by everRun must be in the same subnet or common vLAN, so there is no need to make DNS or Active Directory updates when the primary host/location fails and the VM is started on the secondary XenServer host. All error detection and error handling are completely automated with no human intervention required. For long-distance replication and failover, Marathon does offer an asynchronous DR solution.
Q: Regarding the Marathon HA tool; if your HA tool handles auto failover across sites by replicating the VM files at storage level, how do you manage the network differences (for example, how will tool know which IP address etc to assign to the mirrored/recovered VM) ?
A: everRun VM requires that the servers in the everRun pool be in the same subnet or common vLAN. This allows use of the secondary server and its components without any need to change any networking records or clients to point them to the secondary system. The VM/application environment are identical regardless of which XenServer host they may be running on. The IP address, hostname, and even MAC address are always the same, making any I/O redirection or VM failover completely transparent.
Q: If I have 24 VM’s that are hosted 3 XenServers won’t providing everRun as a fault tolerant solution require me to double up on XenServer hosts to accommodate mirroring VM’s across numerous hosts?
A: The number of VM’s possible is dependent on numerous factors, including hardware and application loads. everRun VM does create a mirrored VM on a secondary host. If there are enough resources available within your three hosts, you shouldn’t need additional hosts.
Q: Does Marathon have plans to support Linux based VM’s?
A: Yes, we do plan to support Linux VM’s but do not have a delivery date scheduled at this time.
Q: Does the everRun product (or another Marathon product) allow Linux virtual machines to run fault tolerant (zero downtime with a physical host failure)?
A: everRun VM does not currently support Linux VM’s, however the level 1 XenServer HA capability available within Essentials for XenServer can protect Linux VM’s.
Q: Fault tolerant VM replication is great, but does XenServer + everRun have a restore point like solution for guest OS corruption\malfunction?
A: everRun VM is licensed per XenServer host for level 2 protection, with level-3 protection being licensed per each VM you wish to protect with complete system-level fault tolerance.
Q: How does everRun differ from Double-Take?
A: everRun VM is a fault tolerant availability solution, while Double-Take is a replication and failover solution designed for long-distant DR. For DR needs, Marathon offers everRun DR, which provides similar capabilities to that of Double-Take.
Q: Referring to the two DL380 servers in your slide… What physical hardware is used to allow the two servers to communicate with each other?
A: The XenServer hosts within an everRun VM configuration are connected either with a direct-attached crossover using GigE interfaces when the pool consists of two XenServer hosts. If there are more than two hosts in the pool, these networks will need to be configured through network switches. We refer to these connections as Availability Links, or A-links.
Q: Is there a Sullivan Group case study or whitepaper?
A: You can view The Sullivan Group case study here. You can also read the other case study we talked about in the webinar, how Argo Capital uses everRun VM to protect Exchange, BlackBerry Enterprise Server and Citrix XenApp, here.
Q: In the pictured scenario of 2 Proliant DL380’s, does the everRun use local storage on each server, or does it use shared storage?
A: everRun has the options of using either shared storage or local independent storage.
Spring has brought a number of welcomed events here in New England – more than one or two days above 40 degrees, Josh Beckett looking good in the Red Sox home opener, and a snow-free driveway and yard (fingers crossed they stay that way).
At Marathon, we’re also looking forward to some other exciting Spring events including Citrix Synergy and Microsoft Tech Ed where we’ll be speaking in a session with Microsoft. And within the coming weeks, we are ramping up to launch the next generation of our flagship everRun technology. We’re not ready to spill the beans, but we can assure you, it includes some industry-first features that can simplify high availability for midsize and smaller companies.
We look forward to releasing this news and other exciting developments in the next few weeks - stay tuned.
When planning your VM workloads, you should be aware of what level of availability each server will need. By splitting the amount of users across multiple VM’s you can provide a level of availability to each set of users based upon your SLA with each business unit in your company. Looking back to the availability pyramid you can choose which level of availability for each mailbox server is needed. For example if you have an executive group that needs to be up with a 24/7 uptime and only limited downtime then level 3 should be your selection on a separate mailbox server. If all of your business units require the same level of availability and have the same SLA in place then you will split your mailbox servers according to usage. Using the chart from section one we can split the users based upon the type of user. For example if you have 1,000 heavy users we would assign 2 vCPU’s to the virtual machine. Always follow Microsoft best practices when deploying the amount of users per core or vCPU.
If we look at Figure 1 we can see that that we have 4 active VM’s spread across two servers with 2 vCPU’s assigned to each. Looking at the example chart above and using figure one we can see that this design example would support 4,000 “Heavy users”. We achieve this by allowing our storage groups on each mailbox VM to support 1,000 “Heavy” users.
Let’s take a look at a basic design with 3 separate types of users spread across 4 servers. We have an executive mailbox store, a mid-management store, and a general user store. In looking over what each teams HA requirement is we have come to the following, the executive team needs 24/7 up time with no downtime except for a maintenance window once a month. The mid-management team can handle some downtime, but only a few minutes each week. The general users have no HA requirement they can be down for an hour a week if needed. So how do we decided what level of availability we would like to use, it’s easy we simply look at the application availability pyramid and we put the appropriate mailbox store at each level:
By using this simple plan you can simplify you’re HA strategy for Exchange. By distributing the mailbox stores across multiple servers on the same hardware you can save rack space as well as provide individual levels of availability based upon different business unit needs.
We had some great questions during the Q & A session of our March webinar with Peter Blum and Sridhar Mullapudi, both of Citrix Systems. We’ve posted the questions and responses here on our blog for everyone’s benefit. This webinar was recorded in case you weren't able to attend, click here to view the webcast!
Q: How big of data pipe is needed for Level 2 (between sites)?
A: The data pipe needed for Level-2 across two sites is an OC3 or higher with 10ms round trip latency.
Q: Can Marathon be used to provide Active - Active access to database applications in geographic disperse locations?
A: Yes, we can with our Level-3 protection and split site option, however the users will only connect to one server at a time.
Q: When is Server 2008 going to be supported?
A: 2008 support will be available on April 30th.
Q: Can you speak to some of the requirements, network speed, latency, etc. necessary to utilize the everRun DR solution?
A: everRun DR can run on any network pipe that can accommodate the amount of change data we will be replicating. Because this is an asynchronous product with compression as well as a bandwidth modeler, we can perform a bandwidth assessment in your environment to tell you what your RPO would be with your current network pipe. Click here to contact us for an assessment
Q: Does everRun provide any corruption detection or warning messages?
A: Since everRun is application agnostic we cannot detect corrupt application data at this time.
Q: When will Marathon’s product work with Dell OEM Citrix XenServer?
A: It is currently being researched and is not assigned for release yet.
