artykul8

I have been using VMware virtualization for quite a few years now, and even though it is generally fast and reliable platform, it does require some extra tuning to improve its performance. Here is a brief collection of tweaks that I personally use on Windows and Mac to speed up and improve I/O performance of VMware virtual machines. These tweaks have become particularly useful in the past couple of years, since larger amount of available RAM on computers and desire to reduce unnecessary write operations to SSD drives, such as full memory swap files.

Tweak: Disable memory swap files .vmem files

In the VMware settings.ini file add the following line:

mainMem.useNamedFile = "FALSE"


Settings.ini file is located file either at C:\ProgramData\VMware\VMware Workstation\ or C:\Documents and Settings\All Users\Application Data\VMware\VMware Workstation\ folders, depending on your operating system.

Note: Unfortunately this parameter does not work for VMware Player, as it always creates virtual machine’s full memory swap file.

For VMware Fusion on Mac and Linux instead of mainMem.useNamedFile you have to set mainMem.backing flag.
VMware Fusion Config files are located at: /Users/username/Library/Preferences/VMware Fusion/preferences and /Users/username/Library/Preferences/VMware Fusion/config

mainMem.backing = "swap"


Tweak: Disable log files for VM
Open your .vmx file in a text editor and add the following line:

logging = "FALSE"


Alternatively you can specify a different location to store the log file, if you ever need them:

log.filename = "c:\Windows\Temp\vm1.log"


Tweak: Disk & Memory I/O Performance Optimization

Disable memory trimming:
MemTrimRate = "0"

Disable page sharing:
sched.mem.pshare.enable = "FALSE"

Disable snapshots if you are not using them and prefer full backups:
snapshot.disabled = "TRUE"

Disable scale down of memory allocation:
MemAllowAutoScaleDown = "FALSE"

Tweak: Disable Unity Mode

Unity might be a great feature for running virtual desktops operating systems, but it is not the most useful for virtualizing server OS. As a sign of enabled unity is presence of GuestAppsCache folder with a large number of files in its appData-subfolder. In order to disable it for your VM, open your .vmx file in a text editor and add the following line:

unity.allowCompositingInGuest="TRUE"

References:

VMware: Troubleshooting hosted disk I/O performance problems
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1008885

VMware: Disk I/O Performance Tips
http://www.vmware.com/support/ws5/doc/ws_performance_diskio.html

VMware: Defragmentation overview
http://blogs.vmware.com/teamfusion/2008/10/tip-defragmenta.html

VMware: Disabling the Workstation Log File or Storing the Log File in a Different Location
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1028

Blog: How can I prevent VMware Workstation Unity Mode from disabling Windows Aero?
http://www.windowsitpro.com/article/virtualization2/q-how-can-i-prevent-vmware-workstation-unity-mode-from-disabling-windows-aero-

Every time you create a new virtual machine in VMware Fusion/Workstation, it is always created with a virtual disk (VMDK) split up into 2Gb files. One of the main reasons for that, I guess would be a limitation of FAT-32 file system – maximum file size of 2Gb. However, if you are no longer using FAT file system and would like to convert the default vmdk into one single pre-allocated file, here is what you can do.

In order to convert the existing virtual disk to a single .vmdk file you would need to use a console application ‘VMware Virtual Disk Manager’ located in '/Library/Application Support/VMWare Fusion' folder.

Follow these two steps:

– open your Mac terminal console (Applications -> Utilities -> Terminal) and navigate to the folder with your VMware disk image

– from that folder run the following command (typing VMware’s diskmanager path with backslash prefixes for space):

/Library/Application\ Support/VMWare\ Fusion/vmware-diskmanager -r originalSplitDisk.vmdk -t 0 targetSingleDisk.vmdk

If you are running VMware Workstation on Windows, you can use the same command with the only difference that vmware-vdiskmanager.exe would be located in a folder where VMware Workstation was installed, e.g.: C:\Program Files\VMware\VMware Workstation.

Documentation and other examples for VMware Virtual Disk Manager use:

• http://www.vmware.com/support/ws45/doc/disks_vdiskmanager_run_ws.html
• http://www.vmware.com/support/ws45/doc/disks_vdiskmanager_eg_ws.html

Being an old fan of VMware products (in particular, the fact that I can run VMware VMs on my MacBook, as well as on Wintel desktop), I found myself utterly disappointed this week, when I tried to convert my physical Windows Server 2008 R2 x64 into a virtual instance.

The latest version of VMware Converter kept crashing on me at the start of the conversion process with the error: “Unable to create a VSS snapshot of the source volume(s).”
More disappointingly, even according to press releases VMware vCenter Converter – the latest and greatest version of VMware Converter, officially doesn’t support Windows 7 or Windows Server 2008 R2 editions (its latest version at the moment is 4.0.1 and dated 2009-12-08).

After a few failed attempts with VMware, I decided to look at Microsoft offerings. Even though, I couldn’t find an official Microsoft converter product, I found something better – a Sysinternals utility Disk2vhd, which can create a virtual hard disk (VHD) out of running physical image.

The most impressive part that the whole process of converting my running 60G RAID-0 hard drive array took only a couple of minutes, with minimal configuration effort – no heavy installation or complex user-interface interactions. All I had to do is select a check box with the volume(s), which needs to be converted and that’s it. Systinternals delivered an impressive utility once again! Kudos to Microsoft for keeping Sysinternals brand alive and bringing new useful tools.

Links:

• Sysinternals
• Mark Russinovich’s Blog
• Download Disk2vhd
• Run Disk2vhd from Live.Sysinternals.com