Free Training – Virtualizing Business Critical Applications (vBCA)

Just found another great free self paced training course offered by VMware. This one is focused on one of my favourite topics, Virtualizing Business Critical Applications.

The course covers thing like what business critical applications can be virtualized efficiently as well as covering common customer objections, some of which are FUD or fiction.

In addition use cases, best practices and value propositions for virtualizing each business-critical application.

One important area the course covers (which can be hard to find reliable information on) is the licensing requirements for applications such as Oracle databases, SAP and the Microsoft Suite e.g.: SQL / Exchange / Sharepoint.

Kudo’s to VMware for releasing this training free of charge. The link to access the course is below.

Virtualizing Business-Critical Applications [V5.X] – Customer

Free VMware NSX training resources

NSX is a hot topic in the software defined networking and SDDC market and has been for some time. It’s the next obvious area of the SDDC which needs to get the benefits of virtualization and make a lot of sense.

I came across a new self paced e-learning course from VMware Education which is offered free of charge.

The course is called  “VMware Network Virtualization Fundamentals” and is a three module course covering the following.

Module 1: Establish the Requirements for Network Virtualization

Module 2: Compare and Contrast Virtual and Physical Networking Solutions

Module 3: Describe Advanced VMware Network Virtualization Solutions

This is a great first step towards understanding Network Virtualization and start on the certification track for NSX starting with VCP-NV.

You can enrol for the course here – VMware Network Virtualization Fundamentals

Enjoy!

Example Architectural Decision – Transparent Page Sharing (TPS) Configuration for QA / Pre-Production Servers

Problem Statement

In a VMware vSphere environment, with future releases of ESXi disabling Transparent Page Sharing by default, what is the most suitable TPS configuration for an environment running Quality Assurance or Pre-Production server workloads?

Assumptions

1. TPS is disabled by default
2. Storage is expensive
3. Two Socket ESXi Hosts have been chosen to align with a scale out methodology.
4. Average Server VM is between 2-4vCPU and 4-8GB Ram with some larger.
5. Memory is the first compute level constraint.
6. HA Admission Control policy used is “Percentage of Cluster Resources reserved for HA”
7. vSphere 5.5 or earlier

Requirements

1. The environment must deliver consistent performance
2. Minimize the cost of shared storage

Motivation

1. Reduce complexity where possible.
2. Maximize the efficiency of the infrastructure

Architectural Decision

Leave TPS disabled (default) and leave Large Memory pages enabled (default).

Justification

1. QA/Pre-Production environments should be as close as possible to the configuration of the actual production environment. This is to ensure consistency between QA/Pre-Production validation and production functionality and performance.
2. Setting 100% memory reservations ensures consistent performance by eliminating the possibility of swapping.
3. The 100% memory reservation also eliminates the capacity usage by the vswap file which saves space on the shared storage as well as reducing the impact on the storage in the event of swapping.
4. RAM is cheaper than Tier 1 storage (which is recommended for vSwap storage to ensure minimal performance impact during swapping) so the increased cost of memory in the hosts is easily offset by the saving in Tier 1 shared storage.
5. Simplicity. Leaving default settings is advantageous from both an architectural and operational perspective.  Example: ESXi Patching can cause settings to revert to default which could negate TPS savings and put a sudden high demand on storage where TPS savings are expected.
6. TPS savings for server workloads is typically much less than with desktop workloads and as a result less attractive.
7. The decision has been made to use 2 socket ESXi hosts and scale out so the TPS savings per host compared to a 4 socket server with double the RAM will be lower.
8. HA admission control will calculate fail-over requirements (when using Percentage of cluster resources reserved for HA) so that performance will be approximately the same in the event of a fail-over due to reserving the full RAM reserved for every VM leading to more consistent performance under a wider range of circumstances.
9. Lower core count (and lower cost) CPUs will likely be viable as RAM will likely be the first constraint for further consolidation.
10. Remove the real or perceived security risk of sensitive information being gathered from other VMs using TPS as described in VMware KB 2080735

Implications

1. Using 100% memory reservations requires ESXi hosts and the cluster be sized at a 1:1 ratio of vRAM to pRAM (Physical RAM) and should include N+1 so a host failure can be tolerated.
2. Increased RAM costs
3. No memory overcommitment can be achieved
4. Potential for lower CPU utilization / overcommitment as RAM may become the first constraint.

Alternatives

1. Use 50% reservation and enable TPS
2. Use no reservation, Enable TPS and disable large pages

Related Articles:

1. Transparent Page Sharing (TPS) Example Architectural Decisions Register

2. The Impact of Transparent Page Sharing (TPS) being disabled by default @josh_odgers (VCDX#90)

3. Future direction of disabling TPS by default and its impact on capacity planning –@FrankDenneman (VCDX #29)

4. Transparent Page Sharing Vulnerable, Yet Largely Irrelevant – @ChrisWahl (VCDX#104)