When reflecting on hard disk defragmentation, perhaps performance optimization first comes to mind. However, reliability might be the more urgent issue on which to focus.
In a recent column, I asked whether it was fair for system managers to pick on the hard drive when it comes to reliability problems, when there were so many other software culprits to chose from, such as worms and other security holes. After all, storage manufacturers have poured billions of dollars into improving the electronics of disk media, head assemblies and drive electronics. (See Pin the Tail on Reliability for more information.)
However, I neglected to mention file fragmentation, which occurs as byproduct of using system software or applicationsin other words, the act of running your computer. While fragmentation isnt directly related to the reliability of the drive hardware (okay, sometimes it is), most folks still point their fingers at the hard drive.
Executive Software International Inc., the maker of the Diskeeper defragmentation utility program, sent me a briefing on the subject titled "The Effects of Disk Fragmentation on System Reliability." (A shorter version of the presentation is available for download, and eWEEKs review of the companys Diskeeper 7.0 Second Edition release this spring is available here. )
Some of the problems are familiar, such as lengthy boot times and increasingly slow backups. Still others can cause problems (or mimic common problems) usually not associated with disk fragmentation.
For example, the report described a test of Windows 2000 and XP in which a custom program fragmented a NTFS-formatted drive. Even though the drive was only filled to 40 percent of capacity, the fragmentation resulted in automatic creation of additional Master File Table (MFT) metadata files. When a single 72MB file was copied to the disk, all the files were corrupted. At a certain point, the OS just cant maintain all of the necessary directories and ensure data integrity. Ouch!
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According to Jeremy Pomerantz, Executive Softwares western sales manager, XP is much faster at fragmenting than Windows 98 or 2000. He pointed to a number of suspects: file technologies introduced or expanded in XP, such as pre-fetching and System Restore services.
The fragmentation will occur on an XP machine without any logins or running programs, Pomerantz said. This tendency can catch sysadmins unawares: "These are the cool features, but XP needs more active maintaining."
At the same time, XP incorporates expanded defragmentation routines (perhaps to compensate in some way for its fragmenting behavior). However, putting these utility programs into action can be difficult. One manager of a large site with whom I spoke declared that the defragmentation utility was "impossible" for most end users.
Regardless, at most sites, this utility is likely unavailable. By design, the built-in defragmentation program requires local admin login, and most enterprise IT managers run a locked-down environment.
"The net result is that the system wont be touched unless theres a service call," Pomerantz added.
And by then, it will be very, very bad indeed.
David Morgenstern is a longtime reporter of the storage industry as well as a veteran of the dotcom boom in the storage-rich fields of professional content creation and digital video.