Tag Archives: vSphere

Example Architectural Decision – Advanced Power Management for vSphere Clusters with Business Critical Applications

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Problem Statement

In a vSphere environment where Business Critical Applications have been successfully virtualized, should Advanced Power Management be used to help reduce data center costs?

Requirements

1. Fully Supported solution

2. Reduce data center costs where possible

3. Business Critical Application performance must not be significantly degraded

Assumptions

1. Supported Hardware

2. vSphere 5.0 or later

3. Admission Control is enabled with >= N+1 redundancy

Constraints

1. None

Motivation

1. Reduce Datacenter costs where possible with minimal/no impact to performance

Architectural Decision

Configure the BIOS to “OS Controlled”

Set ESXi Advanced Power Management to “Balanced”

Justification

1. Power savings can be realized with almost no impact to performance

2. The performance difference between “High performance” & “Balanced” options is insignificant however Power savings can be achieved reducing cost and environmental impacts

3. In the unlikely event of performance issues as a result of using the “Balanced” option, the BIOS is set to OS Controlled so ESXi can be updated without downtime during troubleshooting

4. Advanced Power Management Options (other than “High Performance” & “Balanced”) have proven to have excellent power savings but at a high cost to performance which is not suitable for Business Critical Applications

5. As HA Admission Control is used to provide >=N+1 redundancy, the ESXi hosts will generally not be fully utilized which will give Advanced Power Management opportunities to conserve power

6. The workloads in the cluster/s run 24/7 however demand is generally higher during business hours and some low demand or idle time exists

7. Even where only a small power saving is realized, if performance is not significantly impacted then a faster ROI can be achieved due to cost savings

Implications

1. Where performance issues exist using “Balanced” a vSphere administrator may need to change Advanced Power Management to “High Performance”

Alternatives

1. Use “High Performance”

2. Use “BIOS Controlled”

3. Do not use Advanced Power Management

4. Use Advanced Power Management in conjunction with DPM

Relates Articles

1. Power Management and Performance in ESXi 5.1 – By Rebecca Grider (@RebeccaGrider)

 AdvancedPowerManagement

 

Example Architectural Decision – Storage I/O Control for Clusters Protected by SRM (Example 2 – Use SIOC)

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Problem Statement

In an environment with one or more clusters with virtual machines protected by SRM, What is the most appropriate configuration of Storage I/O control?

Requirements

1. SRM solution must not be impacted

Assumptions

1. vSphere Version 4.1 or later

2. FC (Block) Based Storage OR NFS (File) based Storage

3. Number of datastores is fairly static

Constraints

1. Storage I/O control can prevent unmounting of datastore during a Recovery which can lead to errors being reported by SRM

Motivation

1. Where possible ensure consistent storage performance for all virtual machines

Architectural Decision

Enable and Configure Storage I/O control for all datastores.

Set the congestion threshold to 20ms

Leave the shares value default

Add a Step to each SRM recovery Plan as Step 1 and Select the Step Placement of “Before selected step”.

Configure step type as “Command of SRM Server” and execute the Scheduled Task which will disable SIOC prior to executing a SRM recovery

Justification

1. The benefits of Storage I/O control can still be achieved without impact to the SRM solution

2. SIOC will not impact SRM failover as it will be disabled automatically as part of the SRM recovery plan

3. In the event the Protected site or is lost, SIOC will not prevent failover

Implications

1. Increased complexity for the SRM solution

2. An additional step to excecute a “Command of SRM Server” is required

3. A Scheduled Task will need to be setup and configured with setting “Allow task to be ran on demand”

4. A script to disable SIOC will need to be prepared and configured with all datastores

Alternatives

1. Enable Storage I/O control and leave default settings

2. Enable storage I/O control and set share values on virtual machines

3. Enable Storage I/O control and set a lower “congestion threshold”

4. Enable Storage I/O control and set a higher “congestion threshold”

5. Disable Storage I/O control

Relates Articles

1. Example Architectural Decision –  Storage I/O Control for Clusters Protected by SRM (Example 2 – Don’t Use SIOC)

 

Example Architectural Decision – Storage I/O Control for Clusters Protected by SRM (Example 1 – Don’t Use SIOC)

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Problem Statement

In an environment with one or more clusters with virtual machines protected by SRM, What is the most appropriate configuration of Storage I/O control?

Requirements

1. SRM solution must not be impacted

Assumptions

1. vSphere Version 4.1 or later

2. FC (Block) Based Storage OR NFS (File) based Storage

Constraints

1. Storage I/O control can prevent unmounting of datastore during a Recovery which can lead to errors being reported by SRM

Motivation

1. Where possible ensure consistent storage performance for all virtual machines

2. Simplicity

Architectural Decision

Do not use Storage I/O control for datastores protected by SRM

Justification

1. Storage I/O control can prevent unmounting of datastore during a Recovery which can lead to errors being reported by SRM

2. Storage I/O control can prevent re-mounting of datastore/s during a failback which can lead to errors being reported by SRM and prevent failback without manual intervention

3. Solution does not require any custom steps added to SRM to facilitate a successful recovery

Implications

1. Storage I/O control cannot be used for Datastores protected by SRM

2. In the event of storage contention, SIOC will not be able to ensure fairness between virtual machines based on their share values

3. Storage Performance may degrade significantly during contention

Alternatives

1. Enable Storage I/O control and leave default settings

2. Enable storage I/O control and set share values on virtual machines

3. Enable Storage I/O control and set a lower “congestion threshold”

4. Enable Storage I/O control and set a higher “congestion threshold”

5. Enable Storage I/O control and as part of the DR runsheet, disable SIOC prior to executing a SRM recovery

Relates Articles

1. Example Architectural Decision –  Storage I/O Control for Clusters Protected by SRM (Example 2 – Use SIOC)