Thursday, August 26, 2010

Different implementations for File Server Failover Clustering

I have got this question many times in last few days and also seen a couple of implementations where Hyper-V host clustering was configured alongside File Server failover clustering on same hosts. The intention of this blog is to cover some failover clustering scenarios and reiterating the fact that it is not recommended to install any role in Hyper-V parent partition and if you have configured Hyper-V host clustering to run highly available virtual machines, make sure you do not install any other role in the Hyper-V parent partition and this applies to file server role too. The reason you should not install such a configuration is as you load the hyper-V parent partition by adding more roles, it may affect the performance of the hyper-V host and all the virtual machines running on Host. Check here , here and here where it clearly mentions that Microsoft Hyper-V Server parent partition is specifically for system management.
Second interesting question that comes up in discussion is how to configure File server clustering?
  • Host file server failover clustering.
  • Configure file server in highly available virtual machine.
  • Configure guest file server clustering.
  • Configure guest file server clustering on HA Virtual machines running on Hyper-V host clustering.
 I am not going to reinvent the wheel as Failover Clustering program manager Elden has already shared good thoughts on this topic here and shared below.

Host file server failover clustering.
If host goes down…shares failover to another node ..if host needs to be patched..shares can be failed over to other node. This scenario does not provide you the benefits of virtualization but at same time it is preferable if there is considerably high IO happening on file server.

Configure file server in highly available virtual machine.

HA VM can live migrate or failover from one node to another…for patching purposes we can leverage live migration for moving file server HA VM from one host to another…however during failover the file server VM will take couple of seconds to come online on another node and then server service and SMB shares will come online. Host based failover clustering also monitors the health of the VMs, so if the virtual OS crashes, hangs, or blue screens, it can be automatically restarted, however the end user would need to wait a little longer while the VM state is loaded and started. While Host Clustering can monitor the state of the virtual OS, it does not monitor the health of applications inside the VMs.

Configure guest file server clustering.

You set up a highly available file server failover cluster across two virtual machines which are running on Hyper-V hosts. If one of the Hyper-V host goes unexpectedly down the guest file server cluster VM will turn off and shares will failover to other guest file server cluster VM running on other hyper-V host. In this scenario if we have to patch the hyper-v host we have to failover the shares from one VM to another.

Configure guest file server clustering on HA Virtual machines running on Hyper-V host clustering.

Host+Guest clustering provides both Virtual machine [VM] and application mobility. You will be able to move the guest file server cluster virtual machine from one host to another using live migration without any downtime and cluster service in guest clustering will keep checking the health of server service and SMB shares and will failover the shares from one VM to another when needed. Though you have to be careful while planning Host+Guest clustering and make sure that you configure the anti affinity property for the guest cluster file server workloads so that they don’t preferably exist on same Hyper-V host node. You should also check mark the “auto start” property for HA VM so that when one of the physical host goes down and VM fails over to another node, it starts itself automatically so that file shares become available again. While during the failover as the VM will go down…the cluster service in guest clustering will failover the SMB shares to another HA VM running on another hyper-V host and will reduce the downtime.


There are some nice blog posts by failover cluster team and Jose Bareto which are nice reference.
Hope this blog will answer some of the questions in reference to implementation of file server failover clustering and advantages and disadvantages of each implementation solution. Thanks for your time and hope this was a reading pleasure.


Wednesday, August 25, 2010

Recorded Dynamic Memory and its Architecture presentation

Here you go with the recorded version of Dynamic Memory and its Architecture presentation and its around 33 MB zip file. Though the Demo Gods were not very happy and I did fluttered during demo when task manager values were not giving me the right results but soon I realized that I should not trust task manager output when dynamic memory is enabled for those virtual machines. The same approach which I employed in demo works fine just after the virtual machine reboot as by then DM has not removed or added much memory. Though I am not very satisfied with demo but still hope this is informational and helps you in understanding dynamic memory.

You can download the Live meeting based recorded presentation from here


Saturday, August 14, 2010

Server 2008 R2 SP1 Dynamic Memory & its Architecture Webcast

I will be presenting a Public community webcast on "Dynamic Memory Feature of Windows Server 2008 R2 Service Pack 1 [Beta]" on 18th August i.e. Wednesday at 12PM. The details of joining the session are mentioned below.


Hyper-V Dynamic Memory is a memory management enhancement, designed for production use that enables customers to achieve higher consolidation/VM density ratios. In this session we will see how it works and its Architecture.

Session contains Demo of Dynamic Memory, Memory buffer and priority settings, Dynamic memory performance counters, best practices and considerations when implemented for Hyper-V & Hyper-V host clustering.

Gaurav Anand has invited you to present at an online meeting using Live Meeting.

When: Wednesday, August 18, 2010 12:00 PM-1:00 PM (GMT+05:30)

Where: Live Meeting

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