AdminXP.com: Dividing disk using Fdisk program

Dividing disk using Fdisk program

Harddisk configuration and preparation for formatting. Dividing disk into partitions.

Why? - New disk has no FAT table (File Alocation Table), is not formated and unable to be processed on if it hasnďt been prepared for using in DOS

Whereby? - Using system diskette. Programs as Fdisk.exe, format.com, sys.com shouldnďt be missing. Startup the program from DOS command line.

Switches: [/mbr] [/status]

/mbr - realizes the reconstruction of dividing table, data on the disk stay unchanged. Valid only for the first disk in computer. Important selection when damaging FAT table or assaulting by virus.
/status - excerpts information about disk dividing
Without switch - Initializing fdisk program. Then it is possible to start dividing disk immediately.

Older computers limitation - In older disks which do not support large disks addressing mode (LBA mode - older computers 286, 386, 486) it is not possible to create disk larger then 0,5 GB using Fdisk program. It is possible to elude using special programs and disk drivers (Disk Ontrack Manager - Seagate, Disk Wizard - Western Digital).

Fdisk program older version limitation (DOS, Windows95) If you do not have Win95 SR2 and more recent system you cannot create partition larger then 2 GB using the program and you have to divide it into several parts (system of FAT16 files limitation). In Win95 R2 you can create larger partition sizes using the new system of FAT32 files.

Example to dividing - Values in particular menu are determined for 812 MB disk and its dividing in a half. (primary partition 406MB (marked C:) and extended partition with logical 406 MB unit (marked D:)).

FDISK Options

Current fixed disk drive: 1

Choose one of the following:

1. Create Dos Partition or Logical DOS Drive

2. Set active partition

3. Delete DOS Partition or Logical DOS Drive

4. Display partition information

5. Select next fixed disk drive.

Enter choice: [1] (Default option - if you want change - write another number)

Press Esc to exit FDISK

Create DOS Partition:

After election option number 1 displays:

Create DOS Partition or logical DOS Drive

1. Create Primary DOS Partition

2. Create Extended DOS Partition

3. Create Logical DOS Drive(s) in the Extended DOS Partition

Enter Choice: [1]

Press ESC to return FDISK Options (Return to main menu)

Primary partition is an area from which the operating system is started, it is necessary to be created before having created the extended partition. After entering 1 and approving by Enter button you are asked to add maximum size for primary partition.

Do you wish to use the maximum size for a DOS partition and make the Dos partition active (Y/ N)........? [Y]

Deciding for having disk as a whole and no dividing into parts enter Y for Yes and confirm with Enter button.

Active partition is a partition from which the operating system will be started - see Option no. 3

Then Fdisk sets up the field as an active one and restarts the computer. After restarting enter Format c: /s (formates C: disk and copy the system files).

If you want to create an area smallish then the capacity of the disk enter N.

Create primary DOS Partition

Total disk space is 813 Mbytes (1Mbyte = 1048576 bytes)

Maximum space available for partition is 812 Mbytes (100%)

Enter partition size in Mbytes or percent of disk space (%)

To create a Primary DOS partition .........[50%] (Example 50%)

For creating extended area use Option no. 2

Extended partition - a partition we can divide in several more parts (logical disks). After determination of primary partition it usually takes the rest of the disk and there are then created logical disks.

Create Extended DOS Partition

Partition Status Type Volume Label Mbytes System Usage

C: 1 A PRI DOS 406 FAT16 50%

Total disk space is 812 Mbytes (1Mbyte = 1048576 bytes)

Maximum space available for partition is 406 Mbytes (50%)

Enter partition size in Mbytes or percent of disk space (%)

To create a Primary DOS partition .........[406]

For creating logical units use Option no. 3

Create Logical DOS Drive(s) in the Extended DOS partition

Total partition space is 406 Mbytes (1 Mbyte = 1048576 bytes).

Maximum space avaible for logical drive is 406 Mbytes (100%).

Enter logical drive size ............ [ 406] (Thereby we allocated all the additional area to the logical disk. When we enter smallish one we will be asked again to determine the size for next logical unit.)

Option no. 2 - Selection of the partition for booting the OS:

If you have more then one disk or the disk is divided it is necessary to mark one of the disks as an active one. In the main menu choose Option nr. 2.

Set Active Partition

Partition Status Type Volume Label Mbytes System Usage

C: 1 A PRI DOS 406 FAT16 50%

2 EXT DOS 406 50%

Total disk space is 812 Mbytes (1Mbyte = 1048576 bytes)

Enter the number of the partition you want to make active.......... [1]

After so apportioned disk is need disk formatting

Format c: /S

Format d:

Delete DOS Partition:

Option number - 3

Delete DOS Partition

1. Delete Primary DOS Partition

2. Delete Extended DOS Partition

3. Delete Logical DOS Drive(s) in the Extended DOS Partition

4. Delete Non-DOS Partition

Note: Deleting areas the data saved in the areas will be deleted as well. First you have to delete logical disks, then extended partition and finally primary partition.

When deleting you have to enter: number or letter of partition, label and confirmation of removing.

Display partition information

Option number - 4

Display partition information

Partition Status Type Volume Label Mbytes System Usage

C: 1 A PRI DOS 406 FAT16 50%

2 EXT DOS 406 50%

Total disk space is 812 Mbytes (1Mbyte = 1048576 bytes)

The extended ODS partition contains logical DOS drives. Do you want to display logical drive information? [Y] (Shows information about logical drives in extended partition)

Use - Showing basic information about the disk - size, files system, letter representating a partition, determination of active area

Select next fixed disk drive

Option number - 5

Shows disks in system and enables to choose number of another disk.

Denotation of the abbreviations in the table about disk:

Partition - a letter denoting disk and the number of an area in particular disk.

Status - if contains the letter A it means that the system is booted from this Partition

Type - represents if it is primary (PRI DOS), extended (EXT DOS) or belongs to another program (non DOS, or NTFS - created using Windows NT).
Label - denotation of the disk, not required‚

MB - the area size in MB.

System - specifies files system (FAT16 or FAT32 in Windows 98)

Utilization - the area size in %

Capacity limitation

528MB - Limitation of disk control units (ATA BIOSs) - they do not recognize LBA mode - older computers (286/386/486) could not work with disks larger then 0,5GB, it is possible to elude using special programs (Disk Ontrack Manager - Seagate, Disk Wizard - WD) (1024 cyl 16 heads x 63sectors/track)
2GB - Limitation for DOS and Windows 9x with system of FAT16 files - Limitation of Fdisk program and FAT16 files system
4GB - Windows NT limitation - Partition with FAT16 system cannot be larger then 4GB - not possible to use for creating Fdisk, but the Disk manager is used (Disk management in Windows 2000)
4,2GB - BIOS - Extended CHS - 8192x16x63
8GB - BIOS limitation in some computers - some computers cannot work with disks larger then 8GB (486, older Pentium disks)
33,8GB - (65535 x 16 x 63 x 512 )
137GB - Limit for ATA Specifications (65536 cylinders x x 16heads x 255 sectors/track)

Questions

What does the administration of large disks after starting mean? - If you choose No you create the partitions under FAT16 system which limits you. If you choose Yes you create disks under FAT32 system and then the limitation for FAT32 system is valid.
When starting fdisk program the error information "disk not found" appears. Where could the problem be? - Wrong set up or detection in BIOS, slacken cable, wrong disk configuration (MASTER, SLAVE, SINGLE), wrong disk or controller, SCSI disk type which fdisk does not get on well with.
In the system some absurd label appears and it is not possible to remove it. What to do? - Use command "Label" to change the partition name or use another program for removing (e. g. Disk administrator under Windows NT or Linux)
I've created the partitions, but the system cannot be started from the disk - Is the partition set up as an active one, formatted and is the system transferred on it?

Beware of nonexpert use of the Fdisk and Format programs - you can lose all the data!!