Virtual machines need defragging too

An Osterman Research white paper argues for defragmenting virtual machines

Weighing in on a seemingly perennial question asked by system administrators, IT analysts Osterman Research is recommending that virtual machines be defragmented just as often as physical drives.

"The need for defragmentation is even more acute in virtual environments," stated a newly posted white paper co-authored by Osterman and disk management software vendor Diskeeper. "Physical hardware in a virtualized storage environment must support more operating systems and so can undergo even more disk access and more stress than in a non-virtualized environment."

[Read Computerworld Australia's storage virtualization buying guide]

Disk fragmentation occurs when data is continually written and rewritten to a disk, which can cause data to be scattered across different physical sectors of the physical drive when there is not enough contiguous space to write a file in one uninterrupted block. As a result, when a file is called, the disk must do more work recollecting the bits of the file from different locations, slowing performance.

Windows, as well as third-party software firms, offer defragmenters to reassemble fragmented files. Fragmentation is not as large of a problem on Unix systems, due to the way that the OS writes files to disk.

According to the paper, virtual disks can become just as fragmented as physical disks. For instance, a single file on a virtual disk may be split into four fragments, and the virtual disk itself may be split into another three fragments on the physical disk itself. The cumulative effect of fragmentation on both layers reduces system performance considerably.

"Disk I/O in one virtual machine has a cascading effect on disk I/O in other virtual machines, and so the problem of excessive disk I/O in virtual machines is, in fact, even worse than what would be experienced in a physical disk environment," the paper states.

Not surprisingly, Diskeeper offers virtual disk optimizer software, V-locity, which can prevent virtual machines from becoming too fragmented. But both Microsoft and VMware have recommended defragmentation in various support forums as well.

Joab Jackson covers enterprise software and general technology breaking news for The IDG News Service. Follow Joab on Twitter at @Joab_Jackson. Joab's e-mail address is Joab_Jackson@idg.com

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags MicrosoftVMwaresoftwarevirtualizationServer Virtualizationhardware systemssystem managementdesktop virtualizationapplication virtualizationmaintenanceConfiguration / maintenanceStorage virtualizationOsterman ResearchDiskeeper

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Joab Jackson

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?