How to improve disk I/O performances with VMware Workstation

Posted by virtualization.info Staff   |   Monday, November 21st, 2005   |  

Even on a 2 GB RAM workstation (as mine) VMware virtual machines can run slowly. Too slowly sometimes.

This can depend on a large amount of factors but we can reduce the number to 4 critical issues:

  1. Antivirus real-time protection
    You probably run VMware Workstation on your everyday working computer, and you probably want to stay secure running an antivirus software.

    The most useful feature of any AV is the real-time protection, catching and monitoring I/O accesses of every process for suspicious activities.
    This feature can greatly impact on your VMs performances and should be fine-tuned for virtualization.

    So be sure to create an exclusion filter on your real-time protection settings for .vmdk (VMware virtual disk) and .vmem (VMware virtual memory) files. In this way countinous I/O operations on your virtual machines will not be hit by antivirus checking.

    Note: if you plan to run liveCD operating systems (like Knoppix) inside your VMs or simply often use CD images for installing new software, I highly recommend to exclude .iso files too from AV checking.

  2. HostOS disk fragmentation
    A really performance hitter for virtual machines is a fragmented host OS disk.

    VMs virtual disks are very large (4 GBs at minimum on the average) and are created by default as non preallocated. In other words your virtual disk grow as you install more software on the guest OS till reaching your defined disk limit.
    If you use only one physical disk for everyday work and VMs storing, you probably will use space around a growing virtual disk, obliging your host OS to fragment virtual machines more and more.

    So be sure to:

    • Create a dedicated partition for virtual machines only
    • Create guest OSes virtual disks with Allocate all disk space now option
    • Schedule a daily defragmentation for your virtual machines directories (maybe at launch time or during the night)
  3. Memory trimming
    Workstation checks which part of the guest OS virtual memory is not used and allocates it back to the host OS. This permits to have more concurrent virtual machines running but everytime the guest OS asks back for its memory it suffers a performance degradation.

    So, if you have enough free RAM for all planned concurrent VMs, be sure to disable memory trimming for guest OSes adding the following line to the virtual machine configuration (.vmx) file:

    MemTrimRate=0

    Note: Memory trimming can be disabled through GUI since Workstation 6.0.

  4. Page sharing (quoted from VMware documentation)
    VMware uses a page sharing technique to allow guest memory pages with identical contents to be stored as a single copy-on-write page. Page sharing decreases host memory usage, but consumes system resources, potentially including I/O bandwidth.

    You may want to avoid this overhead for guests for which host memory is plentiful and I/O latency is important. To disable page sharing, add the following line to the virtual machine configuration (.vmx) file:

    sched.mem.pshare.enable=FALSE option

These suggestions will work well for every VMware Workstation 5.x and Player 1.x since both share same engine.


Labels: ,

blog comments powered by Disqus


virtualization.info Newest articles
VMware announcements from its annual VMworld US conference

September 2nd, 2015

During its annual VMworld conference held between August 30 and September 3 in San Fransicso VMware made several announcements. During the keynote on Monday several data center related announcements and…

Release: VMware Workstation 12 Pro, Player 12, Fusion 8 and Fusion Pro 8

August 25th, 2015

VMware today released version 12 of its type-2 client hypervisor products for Microsoft Windows: Workstation Pro and Player and version 8 of its client hypervisor products for Mac OSX: Fusion….

Release: Veeam Management Pack v8 for System Center

August 25th, 2015

Veeam today released version 8.0 of its Management Pack for Microsoft System Center Operations Manager (SCOM or OpsMgr). Using this Management Pack customers running Operations Manager to monitor vSphere and…

Release: Oracle VM VirtualBox 5.0

August 24th, 2015

Oracle has released version 5.0 of its type-2 virtualization platform VM VirtualBox. Starting with a public beta in April this year and some more test builds and a release candidate…

Microsoft releases 3rd technical preview of Windows Server 2016 and System Center 2016

August 19th, 2015

Microsoft today announced the release of the 3rd technical preview of the next version of its Server Operating System (Windows Server 2016 TP3) and corresponding management software (System Center…

From VirtualizationMatrix comes WhatMatrix – UPDATED

August 19th, 2015

We quoted several times Virtualization Matrix, the website created to compare the capabilities of the various virtualization platforms on the market such VMware, Microsoft and Citrix.
This idea sparked…

Release: Linux Integration Services Version 4.0 for Hyper-V

August 18th, 2015

Microsoft has released version 4.0. of its Integration Services for Linux. Hyper-V supports both emulated (“legacy”) and Hyper-V-specific (“synthetic”) devices for Linux virtual machines. When a Linux virtual machine…

Release: Microsoft Desktop Optimization Pack 2015

August 18th, 2015

Microsoft has released version 2015 of its Desktop Optimization Pack (MDOP), which is available as a paid add-on for Microsoft Customers with Software Assurance. In the 2015 release, the…

Release: Microsoft Deployment Toolkit 2013 Update 1

August 18th, 2015

Microsoft has released version 2013 Update 1 of its Deployment Toolkit. The Microsoft Deployment Toolkit (MDT) is a toolset for automating desktop and server operating system deployments. MDT 2013…

Release: Parallels Access 3.0 with Apple Watch Support Capabilities

August 6th, 2015

On August 5, Parallels announced that it has released an update to Parallels Access app for remote access. The American virtualization technology company has added file sharing support to its…

Citrix CEO Mark Templeton plans to retire

July 30th, 2015

On July 28 Citrix disclosed that Mark Templeton, the company CEO, has plans to retire after over 20 years of service, an unexpected news that drew attention on the next…

Citrix announces Q2 2015 results

July 30th, 2015

Citrix announced its financial results for second quarter 2015.
The revenues for the second quarter were $797 million for an increase of 2% compared to Q2 2014.
Net income was $103…

VMware announces results for Q2 2015

July 24th, 2015

VMware released the results about its results for Q2 2015.
VMware, announced a GAAP total revenue growth of $1.52 billion, for an increase of 4 percent compared to Q2 2014. License revenues…

Gartner releases its 2015 Magic Quadrant for x86 Server Virtualization Infrastructure

July 21st, 2015

Gartner released its Magic Quadrant for x86 Server Virtualization Infrastructure for year 2015, once more positioning VMware and Microsoft in the leaders Quadrant.
No surprises in the leaders quadrant, as…

 
Monthly Archive