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
IBM announces earnings for Q2 2016

July 19th, 2016

Yesterday IBM announced its results for Q2 2016.

If we compare with the same quarter in 2015 earnings per share, from continuing operations, decreased 22%. Net income, from continuing operations,…

Red Hat announces earnings for Q1 2017

June 24th, 2016

Red Hat announced its financial results for the first quarter of fiscal year 2017.
Total revenue for the first quarter was $568 million, with an increase of 18% from the…

Release: Red Hat Enterprise Virtualization 4.0 Beta

June 24th, 2016

Today Red Hat released in beta version 4.0 of its KVM-based virtualization platform Red Hat Enterprise Virtualization (RHEV).
As a major release RHEV 4.0 ships a wide series of enhancements including:

Red Hat…

WhatMatrix community keeps growing

June 21st, 2016

virtualization.info has been following WhatMatrix since its inception and, after 6 months since the website has been launched, we are happy to report that its community is growing and contributing…

DockerCon 2016: Day 1 wrap-up

June 21st, 2016

DockerCon 2016 began yesterday in Seattle with a number of announcements from Docker and key partners.

Here is a quick summary of the day:

Docker 1.12 with built-in orchestration: starting…

Release: WinDocks Community Edition

June 14th, 2016

Yesterday, Bellevue (WA) based company WinDocks, released a free edition of its homonymous port of the Docker daemon to Windows called WinDocks Community Edition.

The company, founded by a small…

Docker releases Docker Security Scanning

May 12th, 2016

Containers’ security is one of the emerging topics in those companies moving this technology into production. A few small players emerged to compete exclusively in this portion of the…

RightScale announces Docker Container Management

May 3rd, 2016

RightScale is a Santa Barbara, CA based company, provider of a Software as a Service (SaaS) management solution that so far only supported standard Infrastructure as a Service (IaaS) cloud…

Release: WinDocks 1.0

April 5th, 2016

Yesterday, Bellevue (WA) based company WinDocks, released version 1.0 of its homonymous Docker engine for Windows.
The company, founded by a small group of former Microsoft’s employees, rides Docker’s…

LANDesk Acquires AppSense

March 17th, 2016

LANDesk Software, founded in 1985 and headquartered in Salt Lake City, Utah , provides systems management, security management, service management, asset management and process management solutions with a strong focus…

Release: Red Hat Enterprise Virtualization 3.6

March 15th, 2016

Last week open source giant Red Hat announced the availability of version 3.6 of its KVM-based virtualization platform Red Hat Enterprise Virtualization (RHEV).
While this new release provides the expected…

Docker acquires Conductant

March 4th, 2016

Yesterday Docker announced to have acquired a semi-stealth startup called Conductant, focused on workloads orchestration.

Both Conductant’s founders, Bill Farner and David Chung, have significant enterprise experience coming from…

Cisco acquires CliQr

March 1st, 2016

Today Cisco announced the intent to acquire CliQr Technologies Inc., a privately held company based in San Jose, CA.
CliQr is one of the most promising startups in the Cloud…

Release: VMware vCloud Suite 7 and vRealize Suite 7

February 11th, 2016

Yesterday VMware announced version 7 of both its vCloud and vRealize suites, confirming its efforts to be relevant in the CMPs (Cloud Management Platforms) space.
vRealize Suite 7 is made…

 
Monthly Archive