- 25th October 2013, 06:03 #1New Member
- Join Date
- Oct 2013
When u are getting a warning like low disk space issue
My computer system is windows8. When I try to download something or just run some programs, a warning would show up and said that I have low disk space. The best effective way to clear my disk space/ How can I clear my disk space? I also wonder a simple disk defragmentation could do something. Many thanks.
- 25th October 2013, 15:55 #2
- 26th October 2013, 14:18 #3I also wonder a simple disk defragmentation could do something.
As for defragging - freeing up disk space is not a function of defragging. A disk is divided into a bunch of very small storage locations or "allocation units". The size of the allocation unit is called the "cluster size" and with most modern disks formatted using the NTFS file system, that is just 4Kb. Most files are considerably larger than 4Kb so the files are broken up into segments (fragments), then saved (written) to disk. All a defragger does is rearrange those fragments so they are stored in clusters that are next to each other so the read/write head does not have to jump all over the disk, gathering the fragments to load the entire file. When the fragments are stored in adjacent clusters, the file loads faster.
In the old days, cluster sizes were much larger so defragging could free up some space by more efficiently using each cluster, resulting in fewer partially filled clusters. But with 4Kb cluster size used today, you might free up a few Mb of space, if lucky. But with 1000Mb in 1Gb, that's nothing.
In fact, you need a considerable amount of free disk space just to run a defragging program. This is because the defragger needs space to temporarily store fragments it is moving while it is shuffling about other fragments to make space.
Think of a shuffled deck of playing cards, neatly stacked sitting on the desk. The deck is made up of 4 suits (4 files). The deck takes up just 1 box worth of desk space. If tasked to find the 10, Jack, Queen, King and Ace of hearts, it will take you some time to search through the deck to find them all because the suits are all mixed up (fragmented).
Now arrange the deck in suits (defragment). You do this by temporarily spreading the cards (fragments) out on the desk - and now you are using up a bunch of desk (free disk) space. A lot more than just 1 box worth of space. If you didn't have any free space to spread the cards out, you could not sort them.
Now, once sorted into suits (defragmented) and neatly stacked again, all the cards takes up the same amount of space as they did when mixed. No extra free space was gained. Same on a hard drive.
BUT - if tasked to find the 10, Jack, Queen, King and Ace of hearts again, you can do it much more quickly because they will be stacked right next to each other. Right? That's what degragging a drive does.