Yellow Bricks

by Duncan Epping

whitepaper

New Whitepaper: VMware ESXi 4.1 Operations Guide

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As part of my new role within VMware Technical Marketing I am responsible for creating collateral. Most of you have seen the series of articles about the operational differences between ESX and ESXi. After finalizing the series I transformed them into a whitepaper. I guess one thing that stood out for me while going through that process is that writing a whitepaper is substantially different than writing a blog article and even a book. I am not sure how to explain it, but a whitepaper feels less personal and more official and requires a different writing style. On top of that there are of course multiple reviews, style edits and much more. But anyway, that is not the point of this article… I just wanted to let you know that it is out there, and I hope you will enjoy reading it.

VMware ESXi Operations Guide

Learn how to perform common datacenter tasks in your ESXi environment by seeing the operational differences from the legacy ESX architecture.

Download Operations Guide

Another whitepaper I wanted to point out is the ESXi Migrations Guide. It has been written by my colleague Kyle Gleed and is an excellent start for those looking to migrate from ESX to ESXi in the near future. Not only is the whitepaper very useful, but I am also confident you will appreciate the checklists and the configuration sheet which will help with a smooth transition.

VMware ESXi Migration Guide

Learn how to plan and perform your migration to the ESXi architecture from the legacy ESX framework, with helpful checklists for organizing the steps involved.

Download Migration Guide

Download Migration Checklists

Download Host Configuration Worksheet

We are also working on automating some parts of the upgrade, and I hope to be able to publish an update on that soon.

Good read: VMware vSphere 4.1 Networking Performance

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I just noticed that a new whitepaper was released and as the scoopmeister Eric Sloof hasn’t blogged about it yet I figured, he’s probably sleeping, I would blog about it. I just read the paper and it is a very good read and interesting to know that a single VM can actually saturate the bandwidth of a 10Gbps NIC. Also note the VM to Native comparisons!

Source: VMware vSphere 4.1 Networking Performance

Download:
http://www.vmware.com/files/pdf/techpaper/Performance-Networking-vSphere4-1-WP.pdf

Description

This paper demonstrates that vSphere 4.1 is capable of meeting the performance demands of today’s thoughput-intensive networking applications. The paper presents the results of experiments that used standard benchmarks to measure the networking performance of different operating systems in various configurations. These experiments examine the performance of VMs by looking at VMs that are communicating with external hosts and are communicating among each other, demonstrate how varying the number of vCPUs and vNICs per VM influences performance, and show how the scalability results of overcommitting the number of physical cores on a system by adding four 1-vCPU VMs for every core.

Performance: Thin Provisioning

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I had a discussion about Thin Provisioning with a colleague last week. One of the reasons for me not to recommend it yet for high I/O VMs was performance. I had not seen a white-paper or test yet that showed their was little impact of growing the VMDK. Eric Gray of Vcritical.com had the scoop, VMware just published an excellent whitepaper called “Performance study of VMware vStorage Thin Provisioning“. I highly recommend it!

Surprisingly enough there is no performance penalty for writing to a Thin Provisioned VMDK when it comes to locking. I expected that due to SCSI reservations there would at least be some sort of hit but there isn’t. (Except for zero’ing of course, see paragraph below) The key take away for me still is: operational procedures.

Make sure you set the correct alarms when thin provisioning a VMDK. You need to regularly check what the level of “overcommitment” is, what the total capacity is and the percentage of disk space still available.

Another key take away is around performance though:

The figure shows that the aggregate throughput of the workload is around 180MBps in the post-zeroing phase of both thin and thick disks, and around 60MBps when the disks are in zeroing phase.

In other words, when the disk is zeroed out while writing there’s a HUGE and I mean HUGE performance hit. To avoid this for thick disks there’s an option called “eager zeroed thick”. Although this type is currently only available from the command line and takes longer to provision, as it zeroes out the disk on creation, it could lead to a substantial performance increase. This would only be beneficial for write intensive VMs of course, but it definitely is something that needs to taken into account.

Please note: On page two, bottom, it states that VMDKs on NFS are thin by default. This is not the case. It’s the NFS server that dictates the type of disks used. (Source: page 99)

EMC Powerpath/VE

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My colleague Lee Dilworth, SRM/BC-DR Specialist, pointed me out to an excellent whitepaper by EMC. This whitepaper describes the difference between Powerpath/VE and MRU, Fixed and Round Robin.

Key results:

  • Powerpath/VE provides superior load-balancing performance across multiple paths using FC or iSCSI.
  • Powerpath/VE seamlessly integrates and takes control of all device I/O, path selection, and failover without the need for additional configuration.
  • VMware NMP requires that certain configuration parameters be specified to achieve improved performance.

I recommend reading the whitepaper to get a good understanding of where a customer would benefit from using EMC Powerpath/VE. The whitepaper gives a clear picture of the load balancing capabilities of Powerpath/VE compared to MRU, Fixed and Round Robin.  It also shows that there’s less manual configuration to be done when using Powerpath/VE, and as just revealed by Chad Sakac on twitter an integrated patching solution will be introduced with ESX/vCenter 4.0 Update 1!

Understanding Memory Resource Management in VMware ESX Server

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VMware white-papers are my primary source of information. Almost every single one of them contains valuable information. VMware  just released a brand new white paper titled “Understanding Memory Resource Management in VMware ESX Server” which is most definitely worth reading.

Download:
http://www.vmware.com/files/pdf/perf-vsphere-memory_management.pdf

Description: VMware® ESX™ is a hypervisor designed to efficiently manage hardware resources including CPU, memory, storage, and network among
multiple concurrent virtual machines. This paper describes the basic memory management concepts in ESX, the configuration
options available, and provides results to show the performance impact of these options.