From the Chief Technology Officer at Marathon Technologies

Jerry Melnick

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Q & A for the April 29th webinar: Premier Showing - New everRun 2G Demo

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?

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.

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More Stories By Jerry Melnick

Jerry Melnick (jmelnick@us.sios.com) is responsible for defining corporate strategy and operations at SIOS Technology Corp. (www.us.sios.com), maker of SIOS SAN and #SANLess cluster software (www.clustersyourway.com). He more than 25 years of experience in the enterprise and high availability software industries. He holds a Bachelor of Science degree from Beloit College with graduate work in Computer Engineering and Computer Science at Boston University.