Issue 37.12
This week we tackle a particularly “geeky” topic – that of file fragments – why they exist, why we should care and how to fix them. The short answer for those that really don’t care about why is that files get fragmented which slows down your computer so you need to run a disk defragmentation program (included in your operating system) occasionally to keep your computer running well. In Windows systems, this means clicking on the start button, selecting “Programs”, “Accessories”, “System Tools” and then “Disk Defragmenter”. Often, when you start the program it will indicate you do not need to defragment. If so, you are done because there is no problem.
For those of you who like more info, here goes. When a file is fragmented, it means that it is broken up into many pieces which are stored in various locations on your hard drive. The FAT (or File Allocation Table) keeps track of where all the pieces are and what order to access them in so your file will load correctly when requested. The problem is that it takes time to jump all over the drive to find all the pieces which slows the system down. The reason this is done is that files are stored on the FAS (or First Available Space) approach so as to not waste space on the drive. This was especially important when drives were small. I remember 10 Megabyte Hard drives. A one terrabyte hard drive (pretty standard now) is 100,000 times as large as those early drives.
The FAT begins saving a file by planting a flag where it begins and recording the location so it can find it in the future. It records until it runs into another file and then plants a flag indicating the end of that “fragment”. It then finds the next open space on the drive, plants another flag, records where that is, then goes back and places a “jump to” command at the previous flag so it will know where to continue the file. This process repeats until the file is completely saved. In extremely fragmented drives. a file could conceivably be stored in hundreds of places which requires the FAT to keep track of a large amount of information and the drive read/write heads to jump around all over to load the file. That significantly slows down your ability to load programs or files.
Two analogies may help you understand this. It is kind of like a golf course where the whole course is one file. You travel the first hole, ending at a flag. Then you are directed to the next tee which leads to the next flag which continues until you finish the course. The time between each hole and the next tee is wasted time in the computer as is the time spent checking where you came from and where you are going at the end of each hole (or fragment). Another analogy is like having an old LP record, but the song is broken up into various parts and placed all over the record’s surface. You have a guide showing you where the beginning and ending of each part of the song is, but you have to pick up the needle at the end of each fragment and then drop it where the next part starts and repeat this until the song ends. You can see how it is much better and more efficient in computer terms to just walk straight from the first tee to the eighteenth hole, or to just have the song all on one track and all in the correct order to play it without interruption.
That is what disk defragmenting does. You should probably check your defragmenting software once a month unless it does it regularly for you. Newer operating systems such as Windows 7 do a pretty good job of keeping files connected and defragmented, but you may still want to check occasionally to be sure. And remember; always make sure you have a back up of anything important.
Shaun McCausland has worked in the computer industry for over 30 years, 20 years of it locally with Bits ‘N’ Bytes and Musicomp and currently does in-home and on-site computer consultation, service, training and repair. If you have questions you can reach him at 435-668-7118 or through his website at www.bitsnbytescomputers.com.