Device and Disk Management

SCSI hard disks are named with sdx here x is a hard disk letter. The disk along with the lowest SCSI ID on the first controller will become sda, the next one will become sdb, and many more.

Hard disks are known as hda, hdb, hdc, and etc. An Hda is the master disk on the first controller, an hdb is the slave disk on the first controller and hdc is the master disk on the second controller, and many more.

GNU or Linux systems commonly use a partition scheme where a hard disk could have up to four main partitions. To create more partitions one of these should be made as an extended partition where various logical partitions can be made. A partition takes the name of the disk they belong to, and a number. The first major partition on the first SCSI disk is thus sda1; the second primary partition is sda2, and etc. The first and second logical partition on an extended partition on the first SCSI disk is sda5 and sda6, and many more.

cfdisk can be begin from the command line with the command cfdisk /dev/sdx where x is the SCSI hard disk letter, like a, b, c or d etc. So to partition the first hard disk on the SCSI controller, the command cfdisk /dev/sda should be used.

Whenever cfdisk is begins an interface is get where the current partition table is listed with the names and is begin command buttons on the bottom of the screen. To modify among partitions, the up and down arrow keys have to use. To modify among commands, the left and right arrow keys are to be used.

For delete an existing partition, the up and down keys should be highlighted, the delete command should be selected with the left and right arrows keys and Enter should be pressed.

To make a new partition, a New command could be selected with the left and right arrow keys, and entered. Selection is obtained among a major and a logical partition. Intended for a logical partition the program will automatically make an extended partition. Then the size of the partition (in MB) must be selected. The user must return to the main screen with the Esc key if the value cannot be entered in MB, and select MB with the Units command.

To set the category of a partition for Linux swap or Linux ext2, bootable PReP, the real partition required to be selected, and Type command have to be selected. A list of different types is acquires. On pressing space more selection is obtained. The type which is required is to be typed and the number at the prompt should be entered.

To be able to boot from a main partition, it should be made bootable. The real partition should be highlighted and the Bootable command should be chosen.

After selecting the layout of the disk, the Write command should be chosen. A partition table will be written to disk that will destroy all data on partitions has been modification or deleted.

The Quit command should be selected to exit the program,.

Note:  In   Solaris,   if   a   new   hard disk   is   added,   a   reconfiguration file   is   making in the   root   directory to detect the presence of new hardware and then the system should be shutdown. For connect the new disk to the system and reboot. The disk will be identified through the system. File system should be created using newfs if needed partitions should be created using format command. Make necessary modification in the /etc/vfstab for mounting the new created file system.

The subsequent program shows how to make a /reconfiguare file.

i)Create a /reconfigure file

# touch /reconfigure

#init 0

ii)    Connect the new disk to the system

iii)  Turn on the power

iv)   Boot the system

v)    Make partitions on the disk using the format command (if needed)

# format

vi)        Create file system

# newfs/dev/rdsk/c # t # d # s #

vii)       Make necessary modification in the /etc/vfstab file

Instead of  making a  /reconfigure file    a  reconfigure boot  can  be  performed by  using  b  -r command at the PROM level in order to make the system recognize the presence of a new device. A Hard disk can be added without shutting down the system. In that case•, drvconfig and disks commands have to be used to recognize the new disk. Those commands should be invoked without parameters. On IDE disk Never attempt a low-level format. This will destroy the disk itself.