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
Red Hat acquires FeedHenry

September 19th, 2014

We are living in a mobile world and the future will be more wireless than ever, we are working with technology all the time using our smartphones and tablets, the…

Citrix acquires Virtual

September 18th, 2014

Citrix yesterday announced that it has acquired Virtual. Virtual provides a virtualization platform for iOS and Android which is cloud based. Virtual provides a solution for testing applications without the…

Will HP buy VMware from EMC?

September 17th, 2014

Last week the New York times published an article titled: “EMC explores selling stake in VMware“. While the news that EMC is exploring selling VMware is not new though. Paul…

Docker raises $40 million in series C funding

September 17th, 2014

After raising $15 million in Series B funding in January this year, Docker has announced that it has raised $40 million in Series C funding. Docker states that it will…

Release: VMware Mirage 5.1

September 17th, 2014

VMware has released version 5.1 of its centralized image management for Windows desktops: Mirage.
VMware Mirage is also part of the Horizon Suite, VMware’s end user computing suite that includes…

Release: Proxmox VE 3.3

September 16th, 2014

Proxmox Virtual Environment (VE) is an open source virtualization management solution that leverages KVM technologies.
Yesterday Proxmox Server Solutions GmbH announced the release of version 3.3 of its product that…

Convirture opens a UK based office to explore EMEA market

September 15th, 2014

Convirture the company, founded in 2006 that provides an open source management console to manage virtualization platforms,  announced to have opened a UK- based office which will help the company…

Release: VMware ThinApp 5.1

September 12th, 2014

VMware has released version 5.1 of its application virtualization product ThinApp. Version 5.1 is the follow up of version 5.0 which was released in November last year. The update provides…

Brian Stevens former Red Hat CTO joins Google as VP of Cloud Platforms

September 12th, 2014

Two weeks ago we were wondering about Brian Stevens, who resigned as Red Hat’s CTO, asking ourselves if this could be seen as a “tremendous opportunity” for both.
Red Hat…

HP Acquires Eucalyptus

September 12th, 2014

Yesterday HP announced to have reached a definitive agreement to acquire Eucalyptus, provider of an open source Cloud Solution competing with OpenStack, CloudStack and OpenNebula.
This acquisition will put…

Release: VMware ESXi and vCenter Server 5.5 Update 2

September 12th, 2014

This week VMware released version 5.5 Update 2 of two of its flagship products, ESXi and vCenter Server, updates that were announced at VMworld 2014 in San Francisco.
Among the…

Release: Red Hat Satellite 6

September 11th, 2014

Satellite is Red Hat’s server life-cycle management based on the community project Spacewalk, it basically provides provision, patch, configuration and subscription management across Red Hat’s ecosystem.
Yesterday the Raleigh company…

Release: Oracle VM VirtualBox 4.3.16

September 11th, 2014

Oracle has released a new version of its virtualization platform VM Virtualbox. Version 4.3.16 is considered a maintenance release which can be installed on top of version 4.3. The update…

Microsoft releases limited preview of Migration Accelerator for Azure

September 8th, 2014

Microsoft last week announced a limited preview of Migration Accelerator (MA) for Azure. MA can seamlessly migrate physical, VMware, Amazon Web Services (AWS) and Hyper-V workloads into Azure, automating discovery…

 
Monthly Archive