virtualization

How to cluster SAP ASCS/SCS with SIOS DataKeeper on VMware ESXi Servers

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This article describes the steps you take to prepare the VMware infrastructure for installing and configuring a high-availability SAP ASCS/SCS instance on a Windows failover cluster by using SIOS DataKeeper as the replicated cluster storage.

Create the ASCS VMs

For SAP ASCS / SCS cluster, deploy two VMs on different ESXi Servers.

Based on your deployment type, the host names and the IP addresses of the scenario would be like:

SAP deployment

Host name roleHost nameStatic IP address
1st cluster node ASCS/SCS clusterpr1-ascs-1010.0.0.4
2nd cluster node ASCS/SCS clusterpr1-ascs-1110.0.0.5
Cluster Network Namepr1clust10.0.0.42
ASCS cluster network namepr1-ascscl10.0.0.43
ERS cluster network name (only for ERS2)pr1-erscl10.0.0.44

On each VM add an additional virtual disk. We will later mirror these disks with DataKeeper and use them as part of our cluster.

Add the Windows VMs to the domain

After you assign static IP addresses to the virtual machines, add the virtual machines to the domain.

Install and configure Windows failover cluster

Install the Windows failover cluster feature

Run this command on one of the cluster nodes:

PowerShell

Copy

# Hostnames of the Win cluster for SAP ASCS/SCS

$SAPSID = “PR1”

$ClusterNodes = (“pr1-ascs-10″,”pr1-ascs-11”)

$ClusterName = $SAPSID.ToLower() + “clust”

# Install Windows features.

# After the feature installs, manually reboot both nodes

Invoke-Command $ClusterNodes {Install-WindowsFeature Failover-Clustering, FS-FileServer -IncludeAllSubFeature -IncludeManagementTools }

Once the feature installation has completed, reboot both cluster nodes.

Test and configure Windows failover cluster

Copy

# Hostnames of the Win cluster for SAP ASCS/SCS

$SAPSID = “PR1”

$ClusterNodes = (“pr1-ascs-10″,”pr1-ascs-11”)

$ClusterName = $SAPSID.ToLower() + “clust”

# IP address for cluster network name 

$ClusterStaticIPAddress = “10.0.0.42”

# Test cluster

Test-Cluster –Node $ClusterNodes -Verbose

New-Cluster –Name $ClusterName –Node  $ClusterNodes –StaticAddress $ClusterStaticIPAddress -Verbose

Configure cluster cloud quorum

As you use Windows Server 2016 or 2019, we recommend configuring Azure Cloud Witness, as cluster quorum.

Run this command on one of the cluster nodes:

PowerShell

Copy

$AzureStorageAccountName = “cloudquorumwitness”

Set-ClusterQuorum –CloudWitness –AccountName $AzureStorageAccountName -AccessKey <YourAzureStorageAccessKey> -Verbose

Alternatively you can use a File Share Witness on a 3rd server in your environment. This server should be running on an 3rd ESXi host for redundancy. 

SIOS DataKeeper Cluster Edition for the SAP ASCS/SCS cluster share disk

Now, you have a working Windows Server failover clustering configuration. To install an SAP ASCS/SCS instance, you need a shared disk resource. One of the options is to use SIOS DataKeeper Cluster Edition.

Installing SIOS DataKeeper Cluster Edition for the SAP ASCS/SCS cluster share disk involves these tasks:

  • Install SIOS DataKeeper
  • Configure SIOS DataKeeper

Install SIOS DataKeeper

Install SIOS DataKeeper Cluster Edition on each node in the cluster. To create virtual shared storage with SIOS DataKeeper, create a synced mirror and then simulate cluster shared storage.

Before you install the SIOS software, create the DataKeeperSvc domain user.

Add the DataKeeperSvc domain user to the Local Administrator group on both cluster nodes.

  1. Install the SIOS software on both cluster nodes.
    SIOS installer
    Figure 31: First page of the SIOS DataKeeper installation
    First page of the SIOS DataKeeper installation
  2. In the dialog box, select Yes.
    Figure 32: DataKeeper informs you that a service will be disabled
    DataKeeper informs you that a service will be disabled
  3. In the dialog box, we recommend that you select Domain or Server account.
    Figure 33: User selection for SIOS DataKeeper
    User selection for SIOS DataKeeper
  4. Enter the domain account username and password that you created for SIOS DataKeeper.
    Figure 34: Enter the domain user name and password for the SIOS DataKeeper installation
    Enter the domain user name and password for the SIOS DataKeeper installation
  5. Install the license key for your SIOS DataKeeper instance.Figure 35: Enter your SIOS DataKeeper license key
    Enter your SIOS DataKeeper license key
  6. When prompted, restart the virtual machine.

Configure SIOS DataKeeper

After you install SIOS DataKeeper on both nodes, start the configuration. The goal of the configuration is to have synchronous data replication between the additional disks that are attached to each of the virtual machines.

  1. Start the DataKeeper Management and Configuration tool, and then select Connect Server.
    Figure 36: SIOS DataKeeper Management and Configuration tool
    SIOS DataKeeper Management and Configuration tool
  2. Enter the name or TCP/IP address of the first node the Management and Configuration tool should connect to, and, in a second step, the second node.
    Figure 37: Insert the name or TCP/IP address of the first node the Management and Configuration tool should connect to, and in a second step, the second node
    Insert the name or TCP/IP address of the first node the Management and Configuration tool should connect to, and in a second step, the second node
  3. Create the replication job between the two nodes.
    Figure 38: Create a replication job
    Create a replication job
    A wizard guides you through the process of creating a replication job.
  4. Define the name of the replication job.
    Figure 39: Define the name of the replication job
    Define the name of the replication job

    Define the base data for the node, which should be the current source node
  5. Define the name, TCP/IP address, and disk volume of the target node.
    Figure 41: Define the name, TCP/IP address, and disk volume of the current target node
    Define the name, TCP/IP address, and disk volume of the current target node
  6. Define the compression algorithms. In our example, we recommend that you compress the replication stream. Especially in resynchronization situations, the compression of the replication stream dramatically reduces resynchronization time. Compression uses the CPU and RAM resources of a virtual machine. As the compression rate increases, so does the volume of CPU resources that are used. You can adjust this setting later.
  7. Another setting you need to check is whether the replication occurs asynchronously or synchronously. When you protect SAP ASCS/SCS configurations, you must use synchronous replication.
    Figure 42: Define replication details
    Define replication details
  8. Define whether the volume that is replicated by the replication job should be represented to a Windows Server failover cluster configuration as a shared disk. For the SAP ASCS/SCS configuration, select Yes so that the Windows cluster sees the replicated volume as a shared disk that it can use as a cluster volume.
    Figure 43: Select Yes to set the replicated volume as a cluster volume
    Select Yes to set the replicated volume as a cluster volume
    After the volume is created, the DataKeeper Management and Configuration tool shows that the replication job is active.
    Figure 44: DataKeeper synchronous mirroring for the SAP ASCS/SCS share disk is active
    DataKeeper synchronous mirroring for the SAP ASCS/SCS share disk is active
    Failover Cluster Manager now shows the disk as a DataKeeper disk, as shown in Figure 45:
    Figure 45: Failover Cluster Manager shows the disk that DataKeeper replicated
    Failover Cluster Manager shows the disk that DataKeeper replicated

We don’t describe the DBMS setup in this article because setups vary depending on the DBMS system you use. We assume that high-availability concerns with the DBMS are addressed with the functionalities that different DBMS vendors support 

The installation procedures of SAP NetWeaver ABAP systems, Java systems, and ABAP+Java systems are almost identical. The most significant difference is that an SAP ABAP system has one ASCS instance. The SAP Java system has one SCS instance. The SAP ABAP+Java system has one ASCS instance and one SCS instance running in the same Microsoft failover cluster group. Any installation differences for each SAP NetWeaver installation stack are explicitly mentioned. You can assume that the rest of the steps are the same.

Install SAP with a high-availability ASCS/SCS instance

Important

If you use SIOS to present a shared disk, don’t place your page file on the SIOS DataKeeper mirrored volumes. 

Installing SAP with a high-availability ASCS/SCS instance involves these tasks:

  • Create a virtual host name for the clustered SAP ASCS/SCS instance.
  • Install SAP on the first cluster node.
  • Modify the SAP profile of the ASCS/SCS instance.

Create a virtual host name for the clustered SAP ASCS/SCS instance

  1. In the Windows DNS manager, create a DNS entry for the virtual host name of the ASCS/SCS instance.
    Important

    Figure 1: Define the DNS entry for the SAP ASCS/SCS cluster virtual name and TCP/IP address
    Define the DNS entry for the SAP ASCS/SCS cluster virtual name and TCP/IP address
  2. If you are using the new SAP Enqueue Replication Server 2, which is also a clustered instance, then you need to reserve in DNS a virtual host name for ERS2 as well.

    Figure 1A: Define the DNS entry for the SAP ASCS/SCS cluster virtual name and TCP/IP address
    Define the DNS entry for the SAP ERS2 cluster virtual name and TCP/IP address
  3. To define the IP address that’s assigned to the virtual host name, select DNS Manager > Domain.
    Figure 2: New virtual name and TCP/IP address for SAP ASCS/SCS cluster configuration
    New virtual name and TCP/IP address for SAP ASCS/SCS cluster configuration

Install the SAP first cluster node

  1. Execute the first cluster node option on cluster node A. Select:
    • ABAP system: ASCS instance number 00
    • Java system: SCS instance number 01
    • ABAP+Java system: ASCS instance number 00 and SCS instance number 01
  2. Follow the SAP described installation procedure. Make sure in the start installation option “First Cluster Node”, to choose “Cluster Shared Disk” as configuration option.

The SAP installation documentation describes how to install the first ASCS/SCS cluster node.

Modify the SAP profile of the ASCS/SCS instance

If you have Enqueue Replication Server 1, add SAP profile parameter enque/encni/set_so_keepalive as described below. The profile parameter prevents connections between SAP work processes and the enqueue server from closing when they are idle for too long. The SAP parameter is not required for ERS2.

  1. Add this profile parameter to the SAP ASCS/SCS instance profile, if using ERS1.
  2. Copy

enque/encni/set_so_keepalive = true

  1. For both ERS1 and ERS2, make sure that the keepalive OS parameters are set as described in SAP note 1410736.
  2. To apply the SAP profile parameter changes, restart the SAP ASCS/SCS instance.

Install the database instance

To install the database instance, follow the process that’s described in the SAP installation documentation.

Install the second cluster node

To install the second cluster, follow the steps that are described in the SAP installation guide.

Install the SAP Primary Application Server

Install the Primary Application Server (PAS) instance <SID>-di-0 on the virtual machine that you’ve designated to host the PAS.

Install the SAP Additional Application Server

Install an SAP Additional Application Server (AAS) on all the virtual machines that you’ve designated to host an SAP Application Server instance.

Test the SAP ASCS/SCS instance failover

For the outlined failover tests, we assume that SAP ASCS is active on node A.

  1. Verify that the SAP system can successfully failover from node A to node B Choose one of these options to initiate a failover of the SAP cluster group from cluster node A to cluster node B:
    • Failover Cluster Manager
    • Failover Cluster PowerShell
  2. PowerShell
  3. Copy

$SAPSID = “PR1”     # SAP <SID>

$SAPClusterGroup = “SAP $SAPSID”

Move-ClusterGroup -Name $SAPClusterGroup

  1. Restart cluster node A within the Windows guest operating system. This initiates an automatic failover of the SAP <SID> cluster group from node A to node B.
  2. Restart cluster node A from the vCenter. This initiates an automatic failover of the SAP <SID> cluster group from node A to node B.
  3. Verification

After failover, verify that SIOS DataKeeper is replicating data from source volume drive S on cluster node B to target volume drive S on cluster node A.
Figure 9: SIOS DataKeeper replicates the local volume from cluster node B to cluster node A
SIOS DataKeeper replicates the local volume from cluster node B to cluster node A

How to cluster SAP ASCS/SCS with SIOS DataKeeper on VMware ESXi Servers

Configuring a #SANLess Hyper-V Failover Cluster with DataKeeper Cluster Edition

daveberm1 Comment

Q. What is a SANLess cluster?
A. It is a cluster that uses local storage instead of a SAN.

Q. Why would I want a SANLess cluster?
A. There are a few reasons:

  • Eliminate the cost of a SAN
  • Eliminate the SAN as a single point of failure
  • Take advantage of high speed storage options such a Fusion-io ioDrives and other high speed storage devices that plug in locally
  • Stretch the cluster across geographic locations for disaster recovery
  • Simplify management
  • Eliminate the need for a SAN administrator

Building a SANLess cluster with DataKeeper Cluster Edition is easy. If you know anything about Windows Server Failover Clustering than you already know 99% of the solution. Even if you have never built a Windows Server Failover Cluster before, don’t worry; Microsoft has made it easy and painless. For the beginners, I have written a step-by-step article that tells you how to build a Windows Server 2012 #SANLess cluster in my blog post here: https://clusteringformeremortals.com/2012/12/31/windows-server-2012-clustering-step-by-step/

If you have followed the steps in my post, you will be at the point where you are ready to create your first highly available virtual machine. There are two options for making a highly available virtual machine. The first option assumes that you have an existing virtual machine that you want to make highly available, and the second option assumes you are building a highly available virtual machine from scratch.

Configuring the DataKeeper Volume Cluster Resource

Because a SANLess Hyper-V cluster requires one VM per volume, you will want to make sure you have your storage partitioned so that you have enough volumes for each VM. The storage on each cluster node should be configured identically in terms of drive letters and partition sizes. Once you have the partitions configured properly and your VM resides on the partition you want to replicate, open the DataKeeper interface and walk through the three step wizard to create the DataKeeper Volume Resources as shown in below.

First, open the DataKeeper interface and click on Connect to Server. Do this twice to connect to both servers.

Once you are connected, click on Create Job to create a mirror of the volume that contains the virtual machine you want to make highly available as shown below. In this example we will mirror the E drive.

Whenever possible, keep replication traffic on a private network. In this case, we are using the 10.0.0.0/8 network for replication traffic. This can be a simple patch cable that connects the two servers across two unused NICs.

The final screen shows the options available for mirroring. For local area networks, Synchronous mirroring is preferred. When replicating across wide area networks, you will want to use Asynchronous replication and possibly enable compression. I would not limit the Maximum bandwidth as that could potentially cause your mirror to go out of sync if your rate of change (Disk Right Bytes/sec) exceeds the Maximum bandwidth specified. However, you may want to temporarily enable Maximum bandwidth during the initial mirror creation process, otherwise DataKeeper may flood the network with the initial replication traffic as it tries to get in sync as quickly as possible. Both Maximum bandwidth and Compression settings can be adjusted after the mirror is created. However, you cannot change between Synchronous and Asynchronous mirroring once the mirror has been created without deleting the mirror and recreating it.

At the end of the mirror creation process you will see a popup asking if you want to auto-register this volume as a cluster volume. Select Yes, this will create a DataKeeper volume resource in Failover Clustering Available Storage.

You are now ready to create your highly available VMs.

Option 1 – Clustering an Existing VM

Once again, this procedure assumes you have an existing VM that you want to make highly available. If you do not have an existing VM, you will want to follow the procedure in Option 2 – Creating a Highly Available VM. Otherwise, you should have a VM when looking at Hyper-V Manager as shown below.

All the VM files should already be located on the replicated volume, as shown below. If not, you will have to relocate the files before attempting to cluster the VM.

To begin the clustering process, open up Failover Cluster Manager. Right click on Configure Roles and choose Virtual Machine as the role you want to create.

This will launch the High Availability Wizard. At this point you should select the VM that you want to cluster and step through the wizard as shown below.

You will see that the VM resource will be created, but there will be some warnings. The warnings indicate that the E drive is not currently part of the VM Cluster Resource Group.

To make the DataKeeper Volume E part of the VM Cluster Resource Group, right click on the role and choose Add Storage. Add the DataKeeper Volume that you will see listed in Available Disks.

The last part is to choose the Properties of the Virtual Machine Configuration (not the Virtual Machine) resource and make it dependent upon the storage you just added to the resource group.

You should now be able to start the VM.

Option 2 – Creating a Highly Available VM from Scratch

Assuming you want to create a highly available VM from scratch, you can complete this entire process from the Hyper-V Virtual Machine Manager as shown below. This step assumes that you have already created a mirror of the E drive using DataKeeper as described in Configuring the DataKeeper Volume Resource section.

To get started, open the Failover Cluster Manager and right click on Roles and choose Virtual Machine – New Virtual Machine.

Follow through with the steps of the wizard and select the options that you want to use for the VM. When choosing where to place the VM, select the cluster node that currently is the owner of Available Storage, which will also be the source of the mirror.

Make sure when specifying the Name and Location of the VM, you select the location of the replicated volume.

The rest of the options are up to you. Just make sure the VHD file is located on the replicated volume.

You will see the highly available VM is created, but there is a warning about the storage. You will need to add the DataKeeper Volume Resource to the VM Cluster Resource Group as shown below.

After the DataKeeper Volume is added to the VM Cluster Resource Group, you will need to add the DataKeeper Volume as a dependency of the Virtual Machine Configuration resource.

You now have a highly available virtual machine.

Summary

In this blog post we discussed what constitutes a #SANLess cluster. We discussed how DataKeeper Cluster Edition can be used to build a highly available Hyper-V cluster without the use of a SAN. Once built, the cluster behaves exactly like a SAN based cluster, including having the ability to do Live Migration, Quick Migration and automated failover in the event of unexpected failures.

A #SANLess cluster eliminates the expense of a SAN as well as the single point of failure of a SAN. DataKeeper Cluster Edition supports multiple nodes in a SAN, so configurations that stretch both LAN and WAN are all possible solutions for Hyper-V high availability and disaster recovery. DataKeeper supports any local storage, opening up the possibility of using high speed local attached SSD or NAND Flash storage for high performance without giving up high availability.

 

 

 

 

 

 

 

 

 

 

Configuring a #SANLess Hyper-V Failover Cluster with DataKeeper Cluster Edition

Installing Windows Server 2012 RC on VMware Workstation Step-by-Step

daveberm3 Comments

With Windows Server 2012 RC being released just yesterday, I wanted to see if I could still install it on VMware Workstation as I had done with the Beta version before. The good news is that everything works beautifully. Here is a nice picture of my Windows Server 2012 RC running in VMware Workstation 8.

I was also able to install the Hyper-V Server 2012 RC as well without a problem.

There certainly are a few tricks to be aware of in order to get them to install, so please reference my previous article for the detailed instructions.

https://clusteringformeremortals.com/2012/03/01/how-to-install-windows-server-8-beta-on-vmware-workstation-8/

It probably will only be a matter of time before I put Windows Server 8 RC on my laptop and switch to Hyper-V instead of VMware Workstation, but I’ll probably save that for another day when I don’t have some work to get done!

Installing Windows Server 2012 RC on VMware Workstation Step-by-Step

Windows Server 8 Developer Preview will not support the Hyper-V Role while running on VMware Workstation…at least on my laptop

daveberm6 Comments

Unless someone knows a trick that I don’t, it doesn’t appear as if I will be able to test out some of the Hyper-V clustering features unless I identify some actual hardware for Windows 8. I had hoped that just maybe VMware Workstation 8 would be able to fool Windows 8 into thinking it was actually a physical server, but so far no dice. This article appears to indicate it will work if you have an Intel Nehalem or Intel Core i7 processor, but my two year old Intel Core 2 Duo T9500 doesn’t seem to be able to do the trick.

I added the hypervisor.cpuid.v0 = “FALSE” to the config file and I changed the CPU settings to use Intel VT –x/EPT as shown below.

But this is what I get when I try to enable the Hyper-V role.

Maybe it is time to invest in a new laptop?

Windows Server 8 Developer Preview will not support the Hyper-V Role while running on VMware Workstation…at least on my laptop

Microsoft now officially supports the iSCSI Software Target 3.3 in production

daveberm9 Comments

Just a few weeks ago I wrote an article about how to configure the iSCSI Software Target 3.3 in a cluster environment. While it is great for labs and testing, up until today it was not supported in a production environment. Well…that all changes today! Microsoft just announced that the iSCSI Software Target 3.3 is a freely available download and can be used on a production network.

http://blogs.technet.com/b/josebda/archive/2011/04/04/microsoft-iscsi-software-target-3-3-for-windows-server-2008-r2-available-for-public-download.aspx

This all starts to get interesting once you start considering the possibility of building shared nothing iSCSI Target clusters with DataKeeper Cluster Edition. Build 2-nodes locally for HA and then place a 3rd one in a remote data center for disaster recovery. Now that is a pretty sweet HA/DR solution without having to break the bank!

Microsoft now officially supports the iSCSI Software Target 3.3 in production

Microsoft Virtualization for VMware Professionals – Free Online Classes – March 29 – 31

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Just one week after Microsoft Management Summit 2011 (MMS), Microsoft Learning will be hosting an exclusive three-day Jump Start class specially tailored for VMware and Microsoft virtualization technology pros.  Registration for “Microsoft Virtualization for VMware Professionals” is open now and will be delivered as a FREE online class on March 29-31, 2010 from 10:00am-4:00pm PDT.

 

What’s the high-level overview?

  • This cutting edge course will feature expert instruction and real-world demonstrations of Hyper-V and brand new releases from System Center Virtual Machine Manager 2012 Beta (many of which will be announced just one week earlier at MMS).  Register Now!
  • Day 1 will focus on “Platform” (Hyper-V, virtualization architecture, high availability & clustering)
    • 10:00am – 10:30pm PDT:  Virtualization 360 Overview
    • 10:30am – 12:00pm:  Microsoft Hyper-V Deployment Options & Architecture
    • 1:00pm –   2:00pm:  Differentiating Microsoft and VMware (terminology, etc.)
    • 2:00pm –   4:00pm:  High Availability & Clustering
  • Day 2 will focus on “Management” (System Center Suite, SCVMM 2012 Beta, Opalis, Private Cloud solutions)
    • 10:00am – 11:00pm PDT:  System Center Suite Overview w/ focus on DPM
    • 11:00am – 12:00pm:  Virtual Machine Manager 2012 | Part 1
    • 1:00pm –   1:30pm:  Virtual Machine Manager 2012 | Part 2
    • 1:30pm –   2:30pm:  Automation with System Center Opalis & PowerShell
    • 2:30pm –   4:00pm:  Private Cloud Solutions, Architecture & VMM SSP 2.0
  • Day 3 will focus on “VDI” (VDI Infrastructure/architecture, v-Alliance, application delivery via VDI)
    • 10:00am – 11:00pm PDT:  Virtual Desktop Infrastructure (VDI) Architecture | Part 1
    • 11:00am – 12:00pm:  Virtual Desktop Infrastructure (VDI) Architecture | Part 2
    • 1:00pm –   2:30pm:  v-Alliance Solution Overview
    • 2:30pm –   4:00pm:  Application Delivery for VDI

  • Every section will be team-taught by two of the most respected authorities on virtualization technologies: Microsoft Technical Evangelist Symon Perriman and leading Hyper-V, VMware, and XEN infrastructure consultant, Corey Hynes

Who is the target audience for this training?

Suggested prerequisite skills include real-world experience with Windows Server 2008 R2, virtualization and datacenter management. The course is tailored to these types of roles:

  • IT Professional
  • IT Decision Maker
  • Network Administrators & Architects
  • Storage/Infrastructure Administrators & Architects

 

How do I to register and learn more about this great training opportunity?

  • Register: Visit the Registration Page and sign up for all three sessions
  • Blog: Learn more from the Microsoft Learning Blog
  • Twitter: Here are a few posts you can retweet:
    • Mar. 29-31 “Microsoft #Virtualization for VMware Pros” @SymonPerriman Corey Hynes http://bit.ly/JS-Hyper-V
      @MSLearning #Hyper-V
    • @SysCtrOpalis Mar. 29-31 “Microsoft #Virtualization for VMware Pros” @SymonPerriman Corey Hynes http://bit.ly/JS-Hyper-V
      #Hyper-V
    • Learn all the cool new features in Hyper-V & System Center 2012! SCVMM, Self-Service Portal 2.0, http://bit.ly/JS-Hyper-V
      #Hyper-V #Opalis

What is a “Jump Start” course?

A “Jump Start” course is “team-taught” by two expert instructors in an engaging radio talk show style format.  The idea is to deliver readiness training on strategic and emerging technologies that drive awareness at scale before Microsoft Learning develops mainstream Microsoft Official Courses (MOC) that map to certifications.  All sessions are professionally recorded and distributed through MS Showcase, Channel 9, Zune Marketplace and iTunes for broader reach.

Please join us for this fantastic event!

Microsoft Virtualization for VMware Professionals – Free Online Classes – March 29 – 31

Hyper-V Multi-Site Demo at Tech-Ed 2010 New Orleans

davebermLeave a comment

If you are at Tech-Ed in New Orleans this week make sure you stop by the Windows Server Failover Cluster booth in the Technology Learning Center and have a look at the multi-site Hyper-V cluster demo using SteelEye DataKeeper Cluster Edition as the replication engine. I’ll also be in the booth to answer any questions you may have. SteelEye also has a booth at the show if you would like to discuss becoming a partner or customer!

Hyper-V Multi-Site Demo at Tech-Ed 2010 New Orleans

How to Install Service Packs into a Cluster while also Minimizing Planned Downtime

daveberm1 Comment

I answer this question often enough that I thought I should probably but a link to it in my blog.

http://support.microsoft.com/default.aspx/kb/174799?p=1

This article tells you everything you need to know. However, what you may not realize is that by following the instructions in the article you are minimizing the amount of planned downtime while also giving yourself the opportunity to “test” the update on one node before your upgrade both nodes. If the upgrade does not go well on the first node, at least the application is still running on the second node until you can figure out what went wrong.

This is just one of the side benefits that you get when you cluster at the application layer vs. clustering at the hypervisor layer. If this were simply a VM in an availability group, you would have to schedule downtime to complete the application upgrade and hope that it all went well as the only failback is to restore the VM from backup. As I discussed in earlier articles, there is a benefit to clustering at the hypervisor level, but you have to understand what you are giving up as well.

How to Install Service Packs into a Cluster while also Minimizing Planned Downtime