Partitioning Hard Drives
Article:  Andy Collinson
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Overview:
If you install a new hard drive, or decide to load a second operating system then you will need to partition a hard drive. This article will include partition tables, file systems and help on partitioning.

Hard Drives
The hard drive is the main storage area on a computer holding its operating system (windows, Linux, Mac OSX etc). The amount of data that can be stored depends on the hard drives capacity, usually measured in Gigabytes1 (1GB = 10^9 bytes). The speed which the data can be accessed depends upon the type of hard drive.
IDE and SATA
IDE and SATA drives are mechanical in operation and consist of a rotating platter on which the data is magneticly stored. These drives look similar on the outside, just the connectors are different. The image left shows a SATA drive with case on, the image right shows an IDE drive with case removed. SATA drives are faster than IDE drives. SATA 2 and SATA 3 drives are now available, SATA 3 providing the fastest read and write times.


Solid State Drives
The latest advances in hard drive technology has led to Solid State Drives. 2 Solid state drives have no moving parts, are silent in operation, and have least startup time and fastest data read and write times. They are not susceptible to mechanical shock but are currently the most expensive hard drive.

Partitions
Before a new hard drive can be used the platters are un-magnetized. To store data the hard drive must be partitioned and then a filesystem created. The filesystem leaves the platters magnetized and contains a file index so particular files can be found. A partition is just a container for a proportion of the disk. Hard Disk Geometry
File Systems
Partition Tables
Partitioning Tools

If you install a new hard drive, the first thing you need to do is create a partition on it. Partitioning is not a black art. A partition in easy terms is just a container.
Partition does not end on Cylinder Boundary
If a partition does not start or end on a cylinder boundary or if the partition length is not divisible by the cylinder size, an asterisk (*) is printed after the non-aligned sector number/count. This usually indicates that a partition was created by an operating system that either does not align partitions to cylinder boundaries or that used different disk geometry information. If you know the disk geometry of the other operating system, you could enter the geometry information with the change geometry command (g). For the first partition on the disk and for all logical partitions, if the offset from the beginning of the partition is not equal to the number of sectors per track (i.e., the data does not start on the first head), a number sign (#) is printed after the offset. For the remaining partitions, if the offset is not zero, a number sign will be printed after the offset. This corresponds to the NC flag in the partitions section of the main display.

References
1 Wikipedia
2 Solid State Drives