Tag Archives: vcap

Example Architectural Decision – Site Recovery Manager Server – Physical or Virtual?

Posted on by
Reply

Problem Statement

To ensure Production vSphere environment/s can meet/exceed the required RTOs in the event of a declared site failure, What is the most suitable way to deploy VMware Site Recovery Manager, on a Physical or Virtual machine?

Requirements

1. Meet/Exceed RTO requirements

2. Ensure solution is fully supported

3. SRM be highly available, or be able to be recovered rapidly to ensure Management / Recovery of the Virtual infrastructure

4. Where possible, reduce the CAPEX and OPEX for the solution

5. Ensure the environment can be easily maintained in BAU

Assumptions

1. Sufficient compute capacity in the Management cluster for an additional VM

2. SRM database is hosted on an SQL server

3. vSphere Cluster (ideally Management cluster)  has N+1 availability

Constraints

1. None

Motivation

1. Reduce CAPEX and OPEX

2. Reduce the complexity of BAU maintenance / upgrades

3. Reduce power / cooling / rackspace usage in datacenter

Architectural Decision

Install Site Recovery Manager on a Virtual machine

Justification

1. Ongoing datacenter costs relating to Power / Cooling and Rackspace are avoided

2. Placing Site Recovery Management on a Virtual machine ensures the application benefits from the availability, load balancing, and fault resilience capabilities provided by vSphere

3. The CAPEX of a virtual machine is lower than a physical system especially when taking into consideration network/storage connectivity for the additional hardware where a physical server was used

4. The OPEX of a virtual machine is lower than a physical system due to no hardware maintenance, minimal/no additional power usage , and no cooling costs

3. Improved scale-ability and the ability to dynamically add additional resources (where required) assuming increased resource consumption by the VM. Note: The guest operating system must support Hot Add / Hot Plug and be enabled while the VM is shutdown. Where these features are not supported, virtual hardware can be added with a short outage.

4. Improved manageability as the VMware abstraction layer makes day to day tasks such as backup/recovery easier

5. Ability to non-disruptively migrate to new hardware where EVC is configured in compatible mode and enabled between hosts within a vSphere data center

Alternatives

1. Place SRM on a physical server

Implications

1. For some storage arrays, the SRM server needs to have access to admin LUNs and using a virtual machine may increase complexity by the requirement for RDMs

I would like to Thank James Wirth VCDX#83 (@jimmywally81) for his contribution to this example architectural decision.

Related Articles

1. Site Recovery Manager Deployment Location

2. Swap file location for SRM protected VMs

CloudXClogo

 

 

Example Architectural Decision – Site Recovery Manager Deployment Location

Posted on by
2

Problem Statement

To ensure Production vSphere environment/s can meet/exceed the required RTOs in the event of a declared site failure and easily perform scheduled DR testing, VMware Site Recovery Manager will be used to automated the failover to the secondary site.

What is the most suitable way to deploy Site Recovery Manager to ensure the environment can be maintained with minimal risk/complexity?

Requirements

1. Meet/Exceed RTO requirements
2. Ensure solution is fully supported

Assumptions

1. vCenter is considered a Tier 1 application
2. vSphere 5.1
3. SRM 5.1
4. A single Windows instance hosts vCenter, SSO and Inventory services and is protected by vCenter Heartbeat

Constraints

1. SRM is not protected by vCenter Heartbeat

Motivation

1. Reduce the complexity for BAU maintenance

Architectural Decision

Install Site Recovery Manager on a dedicated Windows 2008 instance

Justification

1. When installing / upgrading /  patching  SRM including Storage Replication Adapters (SRAs) this may require a reboot or troubleshooting which may impact the production vCenter, including SSO and inventory services.

2. Having SRM separate to vCenter ensures the fail over is not unnecessarily delayed in the event of a disaster due to contention with vCenter on the same VM

3. SRM and vCenter work together in the event of an outage, as such they are less complimentary workloads

4. If hosted on vCenter, SRM will then be subject to the same change windows and be impacted during any maintenance performed for applications running on the same OS instance

5. The SRM application has different availability requirements than vCenter, as such if SRM was combined with vCenter, SRM (having a lower availability requirement than vCenter) would have to be treated with the same change management / care as vCenter which would complicate BAU maintenance

6. The SRM service (business) has different maintenance requirements to vCenter, as such they are not suited to be placed on the same VM

7. Having SRM on a dedicated VM aligns with the scaling out recommendation for virtual workloads

8. Having additional components on the same OS increases complexity and may reduce the availability of vCenter

Alternatives

1. Place SRM on the vCenter server

Implications

1. One (1) additional Windows 2008 R2 licenses will be required

2. One (1) additional Windows instance will need to be maintained in BAU

I would like to Thank James Wirth VCDX#83 (@jimmywally81) for his contribution to this example architectural decision.

Related Articles

1. VMware Site Recovery Manager, Physical or Virtual machine?

2. Swap file location for SRM protected VMs

CloudXClogo

 

 

Example Architectural Decision – vSphere 5.1 Single Sign On (SSO) deployment mode across Active/Active Datacenters

Posted on by
Reply

Problem Statement

What is the most suitable deployment mode for vCenter Single-Sign On (SSO) in an environment where there are two (2) physical datacenters running in an Active/Active configuration?

Requirements

1. The solution must be a fully supported configuration
2. Meet/Exceed RTO of 4 hours
3. Environment must support SRM failover between Datacenter A and Datacenter B where an entire datacenter is lost

Assumptions

1.Three (3) vCenter servers will be used, One (1) at Datacenter A and Two (2) at Datacenter B
2. Environment has Two (2) Production clusters (One per Datacenter), and One (1) vCloud Cluster at Datacenter B each with a dedicated vCenter
3. Stretched clusters are not used
4. All vSphere Infrastructure servers (including SSO) are protected by SRM and vSphere HA
5. Inter-site Metropolitan Area Network is high bandwidth (>10Gb) , low latency (<5ms) and highly available (99.999%)
6. The average number of authentications per second for each SSO instance is <30 (Configuration Maximum)

Constraints

1. The environment uses traditional agent based backup solution which may not meet RPO/RTO requirements

Motivation

1. Future proof the environment

Architectural Decision

1. Use “Multi-site” SSO deployment mode
2. Do not use SSO “High Availability” clusters
3. The Primary SSO server will be at Datacenter B
4. The remaining vCenter servers will be “Secondaries” and point to the Datacenter B Primary SSO instance
5. The each SSO instance will be on a dedicated Windows 2008 x64 R2 instance
6. Each SSO instance will use the bundled SQL database
7. (Optional) For greater availability , vCenter Heartbeat will be used to protect each SSO instance

Justification

1. The environment is being designed (where) possible to sustain a Metropolitan Area Network failure between the two (2) datacenters

2. If “High Availability” mode is used, at least one (1) vCenter would be accessing SSO across the MAN link which introduces an unnecessary dependency on the MAN links

3. “High Availability” currently requires manual intervention which can be complicated and problematic

4. “Basic” mode prevents the use of Linked Mode which will make management of the environment more difficult

5. Using Multisite mode allows faster access to authentication services as each SSO instance is configured with Active Directory servers located at the same datacenter.

6. Multisite mode is required for the use of Linked-Mode and Linked Mode will  make day to day management easier

7. If one instance SSO goes offline for any reason, this will not impact production virtual machines. It will simply prevent any authentication to the affected vCenter server.

8. Having the SSO Primary at Datacenter B ensures only traffic from one vCenter (Datacenter A vCenter) traverses the MAN link as the third vCenter (for vCloud Director) is at Datacenter B

9. In the event of Datacenter B having a full datacenter wide failure for any reason, the Primary SSO instance being offline will not impact the management of Datacenter A OR the ability for the environment being recovered by SRM.

10. During an SSO upgrade, multiple vCenter’s cannot co-exist and using a centralized (or shared) SSO instance would overly complicate the upgrade process and lead to extended impact to the vSphere environments.

Alternatives

1. Use “Basic” Mode, resulting in a standalone version of SSO for each vCenter server

2. Use “High Availability Cluster” (Shared the same SSO database and identity sources) with one SSO server per physical datacenter

3. Use “Multisite” deployment with “High Availability Clusters” per datacenter

4. Host SSO database on a SQL Server

5. Run SSO on the vCenter server with or without the SSO database locally

6. Run a single SSO instance shared by all three (3) vCenters and use vCenter Heartbeat running across the MAN to protect SSO

Implications

1. Without a “High Availability Cluster” or SSO being protected by vCenter Heartbeat at each datacenter, the SSO for each site is a Single point of failure where authentication to the affected vCenter will fail

2. In the event of one (1) SSO server failing at Datacenter A, the SSO role does not failover to Datacenter B, or vice versa. In this case, All authentication requests on the site where SSO has failed, will fail.

3. Requires the installable version of SSO, which is Windows Only. The use of the vCenter Server Appliance (VCSA) is not available.

4. Additional Windows 2008 licenses are required for the SSO servers

Related Articles

1. Disabling Single Sign On – Dont Do It! – LongWhiteClouds

2. vSphere 5.1 Single Sign On (SSO) Configuration – Architectural Decision flowchart

I would like to Thank Michael Webster VCDX#66 (@vcdxnz001) for his contribution to this example architectural decision.

CloudXClogo