vcloud

Resource pool shares don’t make sense with vCloud Director?

Duncan Epping · Feb 28, 2012 ·

I’ve had multiple discussions around Resource Pool level shares in vCloud Director over the last 2 years so I figured I would write an article about it. A lot easier to point people to the article instead, and it also allows me to gather feedback on this topic. If you feel I am completely off, please comment… I am going to quote a question which was raised recently.

One aspect of “noise neighbor” that seems to never be discussed within vCloud is the allocation of shares. An organization with a single VM has better CPU resource access per VM than an organization that has 100 VMs. The organization resource pools have equal number of shares, so each VM gets a smaller and smaller allocation of shares as the VM count in an organization virtual data center increases.

Before I explain the rationale behind the design decision around shares behavior in a vCloud environment it is important to understand some of the basics. An Org vDC is nothing more than a resource pool. The chosen “allocation model” for your Org vDC and the specified charateristics determine what your Resource Pool will look like. I wrote a fairly lengthy article about it a while back, if you don’t understand allocation models take a look at it.

When an Org vDC is created on a vSphere layer a resource pool is created and it will typically have the following characteristics. In this example I will use the “Allocation Pool” allocation model as it is the most commonly used:

Org vDC Characteristics –> Resource Pool Characteristics

Total amount of resources –> Limit set to Y
Percentage of resources guaranteed –> Reservation set to X

On top of that each resource pool has a fixed number of shares. The difference between the limit and the reservation is often referred to as the “bust space”. Typically each VM will also have a reservation set. If 80% of your memory resources are guaranteed this will result in a 80% reservation on memory on your VM as well. This means that when you start deploying new VMs in to that resource pool you will be able to create as many until the limit is reached. In other words:

10GHz/10GB allocation pool Org vDC with 80% guaranteed resources = Resource pool with a 10GHz/GB limit and an 8GHz/GB reservation. In this pool you can create as many VMs until you hit those limits. Resources are guaranteed up to 8GHz/8GB!

Now what about those shares? The statement is, will the Org vDC with 100 VMs have less resource access than the Org vDC with only 10 VMs? Lets use that previous example again:

10GHz/10GB allocation pool with 80% resource guaranteed. This results in a resource pool with a 10GHz/10GB limit and an 8GHz/GB reservation.

Two Org VDCs are deployed, and each have the exact same characteristics. In “Org VDC – 1” 10 VMs were provisioned, while in “Org VDC – 2” 100 VMs are provisioned. It should be pointed out that the provider charges these customers for their Org VDC. As both decided to have 8GHz/GB guaranteed that is what they will pay for and when they exceed that “guarantee” they will be charged for it on top of that. They are both capped at 10GHz/GB however.

If there is contention than shares come in to play. But when is that exactly? Well after the 8GHz/GB of resources has been used. So in that case Org VDCs will be fighting over:

limit - reservation

In this scenario that is “10GHz/GB – 8GHz/GB = 2GHz/GB”. Is Org VDC 2 entitled to more resource access than Org VDC 1? No it is not. Let me repeat that, NO Org VDC 2 is not entitled to more resources.

Both Org VDC 1 and Org VDC 2 bought the exact same amount of resource. The only difference is that Org VDC 2 chose to deploy more VMs. Does that mean Org VDC 1’s VMs should receive less access to these resources just because they have less VMs? No they should not have less access! A provider cannot, in any shape or form, decide which Org VDC is entitled to more resources in that burst space, especially not based on the amount of VMs deployed as this gives absolutely no indication of the importance of these workloads.Org VDC 2 should buy more resources to ensure their VMs get what they are demanding.

Org VDC 1 cannot suffer because Org VDC 2 decided to overcommit. Both are paying for an equal slice of the pie… and it is up to themselves to determine how to carve that slice up. If they notice their slice of the pie is not big enough, they should buy a bigger or an extra slice!

However, there is a a scenario where shares can cause a “problem”… If you use “Pay As You Go” and remove all “guarantees” (reservations) and have contention in that scenario each resource pool will get the same access to the resources. If you have resource pools (Org VDCs) with 500 VMs and resource pools with 10 VMs this could indeed lead to a problem for the larger resource pools. Keep in mind that there’s a reason these “guarantees” were introduced in the first place, and overcommitting to the point where resources are completely depleted is most definitely not a best practice.

vCloud Director Appliance Password

Duncan Epping · Jan 26, 2012 ·

Although this is documented on page 59 of the excellent Evaluators Guide I figured it wouldn’t hurt to write a tiny blog post. I found myself googling for it multiple times already with no succes, so there must be more people facing that “problem”. Below you can find the passwords of the vCloud Director Appliance and the embedded database, just in case you need it:

VMware vCloud Director Appliance:
username = root
password = Default0
VMware vCloud Director Appliance/Oracle Database 11g R2 XE instance:
username = vcloud
password = VCloud

While we are at it, these are the passwords for other appliances:

VMware vCenter Server Appliance:
username = root
password = vmware
VMware vShield Manager Appliance:
username = admin
password = default
vSphere Management Assistant (vMA):
username = vi-admin
password = <defined during configuration>
vSphere Data Recovery Appliance:
username = root
password = vmw@re
VMware vCenter Operations Manager
username = admin
password = admin

New session added for PEX

Duncan Epping · Jan 24, 2012 ·

A couple of weeks back I posted my session details for PEX. I just had a session added to my schedule which I wanted to inform you about. This session was originally hosted by no one less than Mike DiPetrillo. Chris Colotti and I have been asked to take over the session.

Session 1262 (Wednesday 2/12 @ 12:30pm): DR of the Cloud and to the Cloud

This session will look at DR and the cloud. Two different DR scenarios will be presented in depth – DR of the cloud and DR to the cloud. DR to the cloud is how end consumers fail over resources to a cloud provider. DR of the cloud is how you fail over cloud resources from one site to another. This session will go in depth on the consumer and provider side of the architecture. We’ll look at how to replicate the data, what applications are primary targets, how to size environments, how to maintain multi-tenancy, and what to avoid when architecting these solutions. This session is a must for anyone considering tier 1 applications for the cloud.

Presenters: Chris Colotti and Duncan Epping

Don’t forget to add it to your schedule, it is going to be a really cool session!

Live Blog: Raising The Bar, Part V

Duncan Epping · Jul 12, 2011 ·

I am live at the Launch event in San Francisco with many other bloggers, journalists and analysts. It is the 12th of July, almost 09:00 PDT and Paul Maritz is about come up on stage to talk about the Cloud Infrastructure launch. This article will be update live during the event as we go.

Paul Maritz is taking the stage… Taking the next step in towards the more automated world.

We need to make infrastructure become something that people can depend on and focus on what is important to their business. Navigating your way forward offering a more dynamic infrastructure that will support your existing applications. Using a more flexible infrastructure, allowing people to take resources and aggregate to larger pools reducing operational costs by automating the use of these resources. More and more use of social media and use of mobile devices to connect anytime anywhere and most importantly securely.

Today we will be talking about a more efficient infrastructure with exists of three stages IT Production, Business Production and IT as a Service. In 2009, the VI 3 era, 30% of the workloads were virtualized…. in 2010 with vSphere 4 we reached 40% and it is expected that in 2011 we will hit 50% virtualized with the majority on vSphere.

Accelerating and Amplifying business agility with vSphere 5! Not only vSphere 5 but the worlds first Cloud Infrastructure suite! In addition to vSphere 5 today we announce vSphere Site Recovery Manager 5 (Business Continuity), vCloud Director 1.5 (Policy, Reporting, Self-Service), vCenter Operations 1.0.1 (Monitoring and Management), vShield 5 (Security and Edge functionality).

VMware vCloud = Hybrid. Your private cloud experience needs to be similar to public cloud experience. VMware allows this through the vCloud offering and vCloud Service Providers. Trusted vCloud partners like Colt, Bluelock, Singtel, Verizon, NYSE Euronext, Softbank and CSC are some of the enablers for this.

Steve Herrod up on stage… I expect it is about to get more technical

Why do these new products matter and how do they fit together. Accelerating the adoption by increasing scalability. ESX 1.0 capable of 5000 IOps, ESX 2.0 ~ 7000 IOps, VI 3 100.000 IOps, vSphere 4 300.000 IOps and vSphere 5.0 1.000.000 IOps. Besides performance availability is key. Both HA and FT have been enhanced and of course SRM 5.0 has been released. Added to SRM 5.0 is vSphere Replication. vSphere Replication allows you to use the network to replicate between sites and different arrays. It will allow you to replicate more workloads with a lower costs. SRM is about datacenter mobility, not only for an outage but also pro-actively moving datacenters after an acquisition.

What does cloud computing really mean? Being able to order what you need and what without knowing what happens behind the scenes. IT will behind the scenes validate if they meet the consumers requirements. vCloud Director is all about Simple Self-Service. Deploy virtual machines but more importantly create new vApps and offer these in your own “app store”. The IT Cloud of the producer is all about offering agility. Virtualization enables automation in a way unheard in a physical environment.

Typically multiple tiers are offered within a cloud environment. The VMware Cloud Infrastructure enable you to do so. Intelligent Policy based Management is key with vCloud Director 1.5. Linked Clones is a very important feature to provision virtual machines “aggressively” within the system. It allows for fast provisiong and save up to 60% of storage.

Profile-Driven Storage and Storage DRS are part of vSphere 5.0. It enables you to map different arrays in to logical entities by a concept called a “datastore cluster” and link these to a profile. Virtual machines will be tagged with a profile and this allows you to validate compliancy. Storage DRS does for storage what DRS does for compute resources. Storage and Network IO Control ensures each virtual machine receives what it is entitled to.

For the SMB market a brand new shared storage appliance is introduced today: vSphere Storage Appliance 1.0. It takes vanilla servers and use local drives and present it as shared storage. It will bring agility and availability through shared storage to the SMB.

Auto-Deploy, PXE booting your ESXi hypervisor in to memory! It allows to spin-up more hosts within minutes instead of hours. Adding capacity has never been this simple?

vSphere 5 offers comprehensive security and isolation capabilities through vShield 5.0. vShield App 5 allows you to select regulations to protect sensitive data. It also enables you to get additional auditing in place.

The Cloud Infrastructure represents more than a million engineering hours, more than 100 additional capabilities, more than two million QA hours, more than 2000 partner certifications to enable this.

Rick Jackson up next discussing licensing.

Industry has traditionally licensed on physical constraints. It makes it difficult to create a cloud environment. Customers need to be able to upgrade to new hardware without having physical boundaries. No more “Cores per Proc” limits, no more “Physical RAM per host license”… vSphere introducing vRAM entitlement. Virtual RAM is the amount of virtual memory configured for a powered on virtual machine. vSphere 5 used pooled vRAM across the entire environment.

Packaging has been simplified and moving from 6 down to 5 packages. vSphere Advanced has been eliminated, all customers currently using Advanced are entitled to vSphere Enterprise.

Join us at VMworld for more details around the new product releases. 10AM virtual show, be there for more technical in-depth details!