introduction to disk partitons

The same HDD can hold up to four primary partitions or three primary partitions and one extended partition. An extended partition, is not limited the number of partitions. The partitions in the extended partition are called logical partitions.

To install an operating system, you need a primary partition instead, to save data a logical partition is sufficient.

You can not create a logical partition, whether you've reached the limit (4 primary partitions), or there is not enough free space in extended partition or beside them.

A partition if it is not formatted, can not be used, the file system are structures of data that are used to organize the computer informations.

There are several types of file system:

FAT used by MS-DOS, Windows 3.x, Windows 95, et but well supported by all current systems (Windows XP and Linux). HDD does not support more than 2 GB The cluster size which is a massive loss of disc space.
This filesystem type is obsolete

FAT32: Evolution of Fat, supported by all systems except MS-DOS, Windows 3.x, Windows 95 First Edition, Windows NT 3.5 and 4. Discs can reach 2 TB (1 terabyte = 1024 GB). Clusters are already smaller.

NTFS used by Windows NT, 2000 and XP. Linux recognizes it. This system supports no less than 400 MB disks, because it requires a lot of space for the structure of the system. The cluster size does not depend on the size of the disk (or partition) and you can choose freely. Finally, the system can automatically repair bad sectors. On the other hand, administration rights are supported.

Linux Ext2 (Ext2FS) used by Linux is not recognized by MS-DOS and all Windows systems. Discs can reach 2 GB and file names up to 255 characters. administrative rights are supported. This filesystem type is obsolete

Linux Ext3 (ext3fs) used by Linux, not recognized by MS-DOS and all Windows systems. Discs can reach 2 TB. This is an improvement alquale ext2fs journaling was added to reduce the risk of corruption.

Linux Ext4 (ext4fs) The ext4 or fourth extended filesystem is a journaling file system for Linux, developed as the successor to ext3.It was born as a series of backward compatible extensions to remove 64-bit storage limits and add other performance improvements to ext3.However, other Linux kernel developers opposed accepting extensions to ext3 for stability reasons,and proposed to fork the source code of ext3, rename it as ext4, and do all the development there, without affecting the current ext3 users

Reiser (ReiserFS), used by Linux, is a journaled file system, and not recognized by MS-DOS and all Windows systems, still used is going out of production.

Linux Swap, used by Linux, not recognized by MS-DOS and all Windows systems, used as area to store information when RAM (memory) of the computer is full.

Unformatted: A partition with no file system.

Check also this nice Hub regarding filesystems: Understanding a Computer File System

There are many software able to work with partitions and filesystems:

FDISK - Dos

FDISK, under windows, recognise only FAT and FAT32 file system . So this solution is not suggested.. It's included on the boot floppy of windows 98, see also: :

• http://www.bootdisk.com/bootdisk.htm
• http://winfuture.de/downloadrubrik,7.html

An hub related to this tool: FDISK DOS Partition Utility Tutorial

FDISK - Linux

Fdisk, it's a command line tool that is included in all linux distributions, is not so user friendly but does the work ! for more informations

• man fdisk.
  
• fdisk : http://www.linuxinfor.com/italian/man8/fdisk.html
• cfdisk : http://www.linuxinfor.com/italian/man8/cfdisk.html

An hub about Linux Fdisk

QTParted

QtParted is a clone of PartitionMagic  and is included in most Linux distributions. This software recognizes all the file systems of Linux and Windows, including the NTFS which can now be resized.Included in Knoppix. View:

• qtparted.sourceforge.net/index.en.html

Gparted

GParted he is a clone of PartitionMagic. GTK, its graphical user interface tries to be as simple as possible. Recognizes and supports a wide variety of file systems, including Microsoft.

We have 3 nice hubs related to this tool (and this how how much it's popular):

GParted - Great Open Source Hard Drive Partition Utility

Logical Drive - GParted

How to Increase VMware Hard Disk Space

Gparted LiveCd

GParted LiveCD isthe version of GParted on a LiveCD. You start on the CD and in less than a minute there is an interface with the ability to make changes as create/delete partitions, resize partitions, both Linux or Windows (FAT32, NTFS) on the hard disk of the host system. View:

Do Backups !

A crash is not predictable! Moreover, the error is human, so even if you're experienced, you may do some mistake. Any software do only what was required and no more. And it does so as specified in its original programming. Fortunately, the machines are still far from the Terminator, is the man who orders! Make a backup of your personal information, the OS can be reinstalled, but your data not !

Some useful resources:

The Best Ways To Backup Your Files And Photos -- Advice And Tips

10 Top Choices for Online Backup Service

PC Backup

Do Scandisk !

If you use Windows and want to work on his partition first do a scan disk.
The operation is long! However, there is no need to do it every week! Every 2 or 3 months is sufficient. Especially if you use just the disk (few data). VeriFace scandisk the hard drive, trying to repair parts (clusters) damaged, and possibly marks them as unusable (lost). The transaction allows us to avoid data loss. Be careful, if there is a big part of clusters lost, just change the hard disk.

perform scandisk (chkdsk) to solve harddisk related errors

Defrag !

Like scandisk if you use windows (yet?) You have to use defragment, with linux you do not have this problem.

In principle, all files are saved one after another hard disk. To avoid losing too much space, the file is cut into small pieces and stored in small portions of the disk, which are clustered. When you edit a file (update, move, delete), the two cases are possible.The size has decreased or increased. If decrease, as there is another file later, a space is released between the two files. But this space would not necessarily be taken after a new file, because too small. Result, the files are scattered in several pieces across the hard drive. Thus, the access time of files stretches! As if the books were scattered in various collections in the library: we need a long time to find the right copy. Must be ordered. And the longer we wait, the more time you need!

Windows 7 Disk Defragmenter: How to Use Windows 7 Disk Defragmenter to defragment your Hard Disk

Basics of defragmenting your hard drive

How Do I Defrag

And if everything go in the worst direction ?

Probably you can recover your data, it just need patience and time (and another working PC !), check these guide as startup:

Laptop Hard Drive Data Recovery How-To

Computer Hard Disk Data Recovery

Conclusions

This would be only an introduction to the basics of disk structures, partitions and filesystems for Linux install your windows with these concepts should be clear to avoid the risk of doing damage.