Archive for February, 2011

Container Objects in vCenter

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When I went through my Install, Manage, Configure(ICM) course, container objects was a concept that took me a while to wrap my head around. The ideas of what object can contain another, along with the difference in features between containers…I guess there was just a lot of facts to get straight.

So I made a chart of which containers can contain what objects/containers. Afterward I have a short description of features for each container object.

Objects Below Can Contain->>> Folder Datacenter Cluster Host vApp Resource Pool VM
Folder

X

X

X

X

X

X

X

Datacenter

X

X

X

X
Cluster

X

X

X

X

Host

X

X

X

vApp

X

X

X

ResourcePool

X

X

X

*This table is true for DRS enabled Clusters

Folders: Can contain any object, or groups of objects.

  • Allows for logical organization of objects based upon any desired criteria
  • Permissions and alarms can be defined for contained objects

Datacenters: For most intents and purposes, this is the root of an environment. Hosts, clusters, VMs, vApps, and Resource Pools all aggregate to a datacenter.

  • IP Pools(DNS, DHCP, IP Ranges)
  • Only Object to appear in all views(Host and Cluster, VM and Templates, Datastores, Networking), besides the vCenter Server :)

Clusters: Groups of hosts used for collective resources management.

  • High Availability
  • Distributed Resource Scheduler

Resource Pool: Manages allocated resources to child objects

  • VMs use memory and CPU that has been allocated to the Resource Pool
  • Limits, Shares and Expandable Reservations

vApp: Is a hybrid between a VM and a Resource Pool.

  • Can be migrated, turned on/off
  • VMs use memory and CPU that has been allocated to the vApp
  • IP Pools(DNS, DHCP, IP Ranges)
  • Designate start(boot) order for child objects
  • Limits, Shares and Expandable Reservations

This is in no way an exhaustive list of all the features and options that these containers are capable of performing. They are simply some of the more prominent features(in my mind).

For more information about this topic, either feel free to ask in the comments or consult VMware’s Datacenter Admin Guide.

As always please leave a comment and let me know what you think!!

Quick Tip: vCenter Keyboard Shortcuts

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vCenter Keyboard Shortcuts

Even though vCenter does a pretty good job of telling us what the keyboard shortcuts are, most of us don’t pay attention until someone tells us directly….I know I didn’t. So here is me telling you directly :)

Also I can’t quite get the formatting to look right…so I apologize if everything isn’t exactly in line.

Inventory Views

  • Search                                  Ctrl+Shift+F
  • Hosts and Clusters          Ctrl+Shift+H
  • VMs and Templates        Ctrl+Shift+V
  • Datastores                          Ctrl+Shift+D
  • Networking                        Ctrl+Shift+N

Administration

  • Roles                                     Ctrl+Shift+R
  • Sessions                               Ctrl+Shift+S
  • Licensing                             Ctrl+Shift+L
  • System Logs                       Ctrl+Shift+O
  • Server Settings                  Ctrl+Shift+I

Management

  • Scheduled Tasks               Ctrl+Shift+T
  • Events                                  Ctrl+Shift+E
  • Maps                                     Ctrl+Shift+M
  • Host Profiles                      Ctrl+Shift+P
  • Customization Specifications Manager Ctrl+Shift+U

Actions on Highlighted Objects(Not all actions are available for all objects)

  • New Folder                         Ctrl+F
  • New Cluster                         Ctrl+L
  • Add Host                              Ctrl+H
  • New VM                                Ctrl+N
  • New vNetwork Distributed Switch Ctrl+K
  • New Resource Pool          Ctrl+O
  • New vApp                            Ctrl+A
  • Add Permission                 Ctrl+P
  • Open in New Window      Ctrl+Alt+N
  • Add Alarm                           Ctrl+M
  • Add Scheduled Task        Ctrl+S

Actions on VMs

  • Power On                            Ctrl+B
  • Power Off                           Ctrl+E
  • Suspend                              Ctrl+Z
  • Reset                                    Ctrl+T
  • Shut Down Guest            Ctrl+D
  • Restart Guest                    Ctrl+R
  • Enter Full Screen              Ctrl+Alt+Enter

Navigating vCenter

  • Back                                      Alt+Left
  • Forward                               Alt+Right
  • Home                                    Alt+Home
  • Cycle Tab Forward           Ctrl+Tab
  • Cycle Tab Backward        Ctrl+Shift+Tab

Did I miss any? Is this useful? Leave me a Comment!

New VMWare Performance Troubleshooting Guide

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VMWare just released(about 15hours ago) their new Performance Troubleshooting guide. This is a great guide that walks us through both causes and solutions, to many issues that us VMWare Admins see on a regular basis.

As they put it on page 7 of the guide:

This document covers performance troubleshooting in a vSphere environment. It uses a guided approach to lead the reader through the observable manifestations of complex hardware/software interactions in order to identify specific
performance problems. For each problem covered, it includes a discussion of the possible root-causes and solutions. In particular, this document covers performance troubleshooting on a VMware vSphere 4.1 host. It focuses on the
most common performance problems which affect an ESX host. Future updates will add more detailed performance information, including troubleshooting information for more advanced problems and multi-host vSphere deployments.

Long story short, check out the guide and VMWare’s blog post here to get the full story. Oh and just do yourself a favor and go pick up the guide :)

VMWare Data Recovery Now Available to All!

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Not sure if everyone has seen this one yet. VMWare just announced that VDR is now included in Standard, which essentially means that now everyone has access to it. So if you or your company are paying a bunch of money for a backup solution, you now have  an alternative Free option.

I am a fan of VDR myself. Great interface, easy to use, dedupe. The fact that it’s free doesn’t hurt either.

For the full article at VMWare Data Recover is now included in Standard

Quick Tip: vCenter Logging Statistics

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When doing an Advanced Performance Chart in vCenter, do you ever wonder why you can’t choose the same metrics for a date range as you can for real-time?
Well, I am happy you asked.

The metrics you can choose from are based upon the vCenter Statistics Level you have set. Go to Administration-vCenter Server Settings-Statistics

vCenter Statistics Levels

vCenter Statistics Levels

The higher the level you set, the more metrics you will be able to choose in the performance charts. I personally keep mine at 4(the highest), but that is mainly because I have a small environment and am not too worried about the increase in database size. In general, 4 is recommended for debugging. For a list of the level and what metrics are associated with each, check Here.

It should also be noted that changing the level is not retroactive. For example, if you are just now changing your level from 1 to 2, you are not going to now be able to see vm swap out rates for the last year. For this reason it is a good practice to set the level you want to have immediately so you have your data later.

Let me know what you think of the post! I am thinking about making “Quick Tip” a regular around these parts

Conrad

VM Memory Usage Stats: vCenter vs. Windows

7

Although there is all kinds of information out there regarding this very topic, I had a hard time getting all of this straight in my head a couple months back. There just didn’t really seem to be a definitive guide or article about this topic to help anyone. Granted I am not saying that this will be The Definitive Guide by any means, but it certainly doesn’t hurt to give it a shot.  Also it seems like a pretty alright first article to get myself out on those interwebs :)

My confusion came when I was recommending to my colleague and supervisor that we lower the allocated memory to several VMs. We were approaching being very overcommited on our hosts in terms of memory and there were several guests that had not even used more 19% of their allocation in the last several months.

Their first instinct is to look at what the guest is reporting in terms of memory usage. This I knew wasn’t really the best idea since the guest is generally unaware of the host on which it is running. Their first stop was the guest Task Manager.

Task Manager Performance Tab

Also in the Guest we took a look at Resource Monitor

ResourceMonitor

Taking a look at these, it can be very, Very misleading as to what the guest OS is using in terms of memory. From this picture it seems as though the guest is using 73% of its memory, which is much higher than the less than 19% I had been reporting from vCenter.

Memory Usage in vCenter

Zooming Up

What exactly is going on here?!?

To understand what is happening, we have to first understand what these terms mean

Inside the Guest OS

  • Commit (KB) =”Amount of virtual memory that is reserved for use by a process.”
    In other words, this is the amount of memory that a guest process has reserved, which doesn’t necessarily mean it is actively using it.
  • Working Set (KB)=”Amount of memory in the private working set plus the amount of memory the process is using that can be shared by other processes.”
    This is obviously a pretty vague description, also defined/described as “set of pages in the virtual address space of the process that are currently resident in physical memory”. This second description is MUCH better. What this is saying is that the working set is memory from the process that has been assigned a location on the memory. Again this isn’t memory necessarily being actively used/accessed, but just memory that has a residence/location. An analogy that just came to me(so be prepared)…Think of it as a hotel room that has been assigned to you. You have that whole room if you want it, but its possible you may only Really use the room for sleeping. Which means even though that location is assigned to you, you aren’t actively using it for a majority of the time you have it. You can be so greedy sometimes!!! :)
    Similarly some processes like to acquire and hold on to memory even though they are not actively using it.
  • Shared (KB)= Don’t need a quote for this one. Essentially the memory that is being shared with another process
  • Private (KB)= This is the amount of memory that is assigned only to you.

References
What do the Task Manager memory columns mean?
Working Set

Yes, you figured it out. Private+Shared=WorkingSet

Now for memory as vCenter views it.

  • Granted= The amount of memory vCenter presents to the VM/Guest. This is the amount of  ”physical” memory the guest believes it has.
  • Consumed=”..the amount of machine memory allocated to the virtual machine, accounting for the savings in shared memory.”

vSphere Resource Management Guide page 34

  • Active= This is the tricky one…
    “ESX uses a statistical sampling approach to estimate the aggregate virtual machine working set size without any guest involvement. At the beginning of each sampling period, the hypervisor intentionally invalidates several randomly selected guest physical pages and starts to monitor the guest accesses to them. At the end of the sampling period, the fraction of actively used memory can be estimated
    as the fraction of the invalidated pages that are re-accessed by the guest during the epoch. ESX uses a statistical sampling approach to estimate the aggregate virtual machine working set size without any guest involvement. At the beginning of each sampling period, the hypervisor intentionally invalidates several randomly selected guest physical pages and starts to monitor the guest accesses to them. At the end of the sampling period, the fraction of actively used memory can be estimated as the fraction of the invalidated pages that are re-accessed by the guest during the epoch.”

    In layman’s terms, vCenter and Esx/Esxi have a really complicated algorithm for calculating how much of the memory is actively, yes actively being used by the guest.

Understanding Resource Memory Management….

For me personally, I like the Active metric  a lot. In general though it is important to take a look at several of the metrics in order to really get a sense of what is happening with a guest.

There are many different ways to approach and look at memory usage in a guest/vm. As long as you can take a holistic view to memory everything starts to come together and make a bit more sense.

For a great article on using esxtop for measuring performance, check out Yellow-Bricks

Anyway, I hope this has been helpful and/or informative. Please let me know what you think or if I made some sort of seriously huge mistake somewhere.

Conrad

Virtualization on Android

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Just saw this great article on engadget. The post isn’t that long but the video from MWC is pretty amazing. The speed at which the phone not only switches between the OS’s but runs them is incredible.

Check out the article here

The Beginning

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Greetings All!!

I just put up this site and I really hope it turns out to be useful to a lot of people. As a  summary, I started this blog to be useful to those of us who aren’t experts in VMWare and need some of the even basic stuff explained to us. For more details check out the about section.

I should be getting my first qualtiy post up in the next day or two.

Also if there are any articles or information you want me to post about please please please contact me!!!

Conrad

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