How partitions happen?
Taking a hard disk from its pristine, newly manufactured state to fully functional DOS or window ’95 storage area require three steps: physical formatting, partitioning, and logical formatting.
To understand what each step does, let’s take a brief look at how hard disks operate. Hard disks are mechanical devices consisting of several stacked platters (small, round metal disks treated to store magnetic charges on both side), a spindle around which the platters rotate (much like the center post on a record turntable), and read and write heads attached to the disks by a mechanical arm. The read and write heads allow magnetic charges to be stored on the disk (as bits) and retrieved from it. When you direct a program to load a file from the disk, the platters spin around the spindle and the read head moves back and forth over the platters until it locates the desired bits. Software in the hard disk and the hard disk controller then load the bits into the RAM. When you save data, your computer transfer a series of bits to the hard disk, recorded by the write heads as magnetic charges.
From the stand point of your computer, the hard disk is completely useless until it undergoes the formatting and partitioning stages. The first of these stages is physical or low-level formatting that in most cases is handled by the manufacture (order drivers and SCSI drivers have utilities that refresh low-level formats, but IDE drivers don’t). Low-level formatting essentially gives the disk its physical structure. It adds tracks, sector, and cylinders, terms with which you’re ever had the pleasure of installing a new hard disk. You can think of tracks as begin like the grooves on a long playing record, although tracks are laid out in separate concentric circles rather than one long continuous spiral like the grooves on an LP. Tracks are divided into sectors each of which can store a given amount of data, and each platter has its own tracks and sectors. A cylinder encompasses all platters comprising the corresponding tracks—that is, the tracks that are the same distance from the spindle –on each. To visualise cylinders think of a tall stacks of pancakes and a numbers of drinking glasses, each having a different diameter. Center a glass above the pancakes then push down right through the entire stake. Then do the same with each remaining glass. The vertical configurations you’ve produced are cylinders.
Once a hard disk has been physical formatted, it can be divides into physical regions called partitions. Each partition occupies a group of contiguous cylinders and with some operating systems (Linux, for example), you can specify precisely which cylinders you want each partition to occupy. To purpose behind partitioning is segment your hard disk, for organisation’s sake and also to let you run multiple operating system on a single computer. Each operating system works best (and sometimes solely) with its own file system, and only one file system can exist in a single partition. Under some file system, there’s third reason for multiple partitions—to cut down on wasted space. We’ll deal with all these reasons a little later in the article. Each with your partitions in place, the hard disk is still useless in your computer. To make each partition capable of storing information, it must be logically formatted. Where physical formatting gives you disk it’s physical structure, logical formatting (which is unrelated to physical formatting) provides a means of exchanging data with a operating system by giving the disk a logical structure, the file system. When you use the format command in DOS or the format menu item in window explorer, you are initiating a logical format of entire a disk or a hard disk.
