Category Archive for: ‘VMware’

On 29th january I visited the VDI Performance Summit which was organized by LoginVSI. Login VSI provides performance insights for virtualized desktop environments such as Citrix XenApp, XenDesktop, Microsoft RDS and VMware Horizon View.
The summit was, of course, organized around the LoginVSI tool. In this blog post I will tell you the 5 quick takes of the conference.

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1. Automated testing with LoginVSI

When you put effort in repeatable tests, you can run the test several time’s and see if the performance of the VDI/SBC infrastructure is increasing, stable or decreasing. This is of course for each performance test, but I think in VDI environments it is not common to run a performance test each month or quarter.
As performance tests are always about reducing risks in production. To avoid huge costs, a good scenario is to run the test against one host and see if you have the desired results in terms of response time and capacity for one host.

2. Performance impact of different Windows versions on your VDI infrastructure

With the introduction of Windows 10 Microsoft is releasing new versions of Windows more often. Mark Plettenberg presented the following sheet in his keynote.

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I found it really interesting to see the decrease in number of users per server. The decrease was also related to the Meltdown and Spectre patches introduced in those Windows versions.

3. Removing all Windows Store apps will give a huge performance boost

Rob Beekmans showed us that removing the built-in Windows App (all the games and other things you probably don’t need except the calculator) will give the most of the optimization. All the other minor things will not result in a huge improvement of users per server / and or lower the cpu usage.

More Users per ServerLess CPU usage

Someone, I forgot who said this, stated that in a performance test the background task of Windows will not run because the system does not get idle. So that needs to be considered before only implementing this optimization in a production environment.

4. Power settings in BIOS can affect the performance test

Servers running on a non-high performance profile in the BIOS / Windows settings will give weird results in the performance tests.

Run all the servers in high-performance mode, which is more economic and sustainable than adding more servers to the environment.

5. Which tools do the experts use to tune & prove the performance?

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This were the tools mentioned in the keynote, but there were also some additions from the audience:



It was an interesting day in the Johan Cruijff ArenA and I hope that the event will be organized again with new content in an another year.

2019-01-29 08.13.07

Mount VMFS on Centos 7 or another Linux distro

Why VMFS on CentOS 7?
I was running a VMware ESXi server since 4 years. In VMware ESXi the options for local storage are limited, especially when you like redundant storage. The option is to buy a Raid adapter. I decided to move to CentOS with ZFS storage.
Moving the VM’s to a Linux disk can be done by moving all the files to a NFS share, but an another option is to mount the VMFS filesystem. This is not natively available in Linux, but with fuse and vmfs-tools you can make it available. In this article I will describe how I did the installation and movement of the VM’s.

My baseline tools
I did a plain CentOS 7 installation, after the installation finished succesfully I connected my harddrive with the VMFS file system to the Linux box.
The VMFS driver is not natively available, so you need to compile it yourself. Glandium programmed a userspace VMFS driver for linux, more about this can be found here:

Howto compile VMFS for CentOS 7?
Enable the EPEL repository for additional packages

sudo rpm -Uvh epel-release-7*.rpm

Install the following packages for userspace filesystems

yum install libuuid-devel
yum install fuse fuse-devel 

Download the VMFS sourcecode

tar -xvzf vmfs-tools*

Unpack and compile

cd vmfs-tools-0.2.5
make install

The programs will be installed in /usr/local/sbin

To mount a VMFS file system:

./vmfs-fuse /dev/sdb1 /mount

*When you recognize that vmfs-fuse command is not available on you’re system make sure that fuse, fuse-devel and libuuid-devel is installed before compiling.

Files can now be accessed from /mount

Thin-provisioned VMDK’s are copied as Pre-Allocated VMDK’s
I copied all the vm’s to my local Linux file system, but had some issues with the thin-provisoned vmdk’s. The become pre-allocated vmdk’s which uses a lot of space. With the following command you can convert them back to growing disks:

vmware-vdiskmanager -r sourceDisk.vmdk -t 0 targetDisk.vmdk

Installing the VMFS drives on Linux / CentOS can be usefull in case of migrations, but also in case of an emergency. It is realative easy to browse you’re VMFS filesystem from a non-VMware host.