To make a Linux USB system that starts with a U disk

simple steps to make a Linux system that starts with a U disk:

　　First, the U disk for processing

1. Partition: (Insert the U disk)

# FDISK/DEV/SDB

D Enter Delete the existing partition

N Enter a new primary partition

W Enter Save Settings

# PARTPROBE/DEV/SDB Flash u disk

2. Set USB disk partition for active partition

# FDISK/DEV/SDB

A Enter is set to active partition

1 Enter Select partition

3. To format the hard disk partition format into ext3 format

# MKFS.EXT3/DEV/SDB1

　　Second, pack filesystem package (objective: to generate the root of the Root,usr,var ... etc directory)

1. Configure Good Yum

2. Load u disk to/net

# mount/dev/sdb1/net

3. Installation

# yum-y Install--installrot=/net filesystem

After the installation is complete, you can view multiple catalogs under/net

　　Third, loading system startup items

1.# cp/boot/vmlinuz-2.6.18-128.el5/net/boot/

2. Generate initrd.img ' uname-r ' to take the system version number

# mkinitrd--with=usb-storage/net/boot/initrd-usb.img ' uname-r '

3. See if there are Vmlinuz and INITRD under/net/boot/

　　Iv. Production of boot loader (GRUB)

1.# yum-y Install--installroot=/net Grub

2.grub.conf is not automatically generated, to be created manually

# cp/boot/grub/grub.conf/net/boot/grub/grub.conf and make changes

# cat/net/boot/grub.conf

Default = 0

Timeout = 5

Title Redhat-usb-linux

Root (hd0,0)

Kernel/boot/vmlinuz-2.6.18-128.el5 ro root=/dev/sdb1 Init=/dev/bash

Initrd/boot/initrd-usb.img

The content to be filled out here is consistent with the file name under/net/boot/grub/

　　V. Install Command library files

# yum-y Install--installroot=/net bash coreutils pam setup vim-enhanced vim-minimal util-

Linux net-tools sysvinit passwd shadow-utils authconfig

The package name can be viewed through rpm-qf/bin/mount

At this point chroot/net can use the command you just installed.

　　Vi. Creating a disk partition

# Mknod/net/dev/sdb B 8 16

# MKNOD/NET/DEV/SDB1 B 8 17

b for block devices, 8 for the main device number, 16, 17 for the secondary device number

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| For an explanation of the device number:

| 1. For a scsi/sata hard drive (format sd*), the main device number is 8,

| The first hard disk's secondary device number is 0-15, the second hard disk's secondary device number is 16-31, and so on. Because for the hard disk, the primary partition can be up to 4, 3 primary partitions an extended partition,

| Zones can still be partitioned, but the total number of partitions is 16, so the secondary device number for each hard disk is 16 (0-15,16-31).

| 2. For an IDE hard disk (format hd*), the main device number is 3, the secondary device number is 0-63, and the second block is 64-127.

| 3.# ls-l/dev/sd*

| Brw-r-----1 Root disk 8, 0 10-16 14:53/DEV/SDA

| Brw-r-----1 Root Disk 8, 1 10-16 14:54/dev/sda1

| Brw-r-----1 Root Disk 8, 2 10-16 14:53/dev/sda2

| Brw-r-----1 Root Disk 8, 3 10-16 14:54/dev/sda3

| Brw-r-----1 Root disk 8, 10-16 15:50/dev/sdb

| Brw-r-----1 Root disk 8, 10-16 15:50/DEV/SDB1

| Brw-r-----1 Root disk 8, 10-16 15:50/DEV/SDC

| Brw-r-----1 Root disk 8, 10-16 15:50/DEV/SDC4

| The above is a host I inserted 1 hard drives, two U disk display, we can see the display of equipment number.

| 4. All files in Linux, hardware is also reflected through the document, all hardware devices are displayed in the/dev/.

| 5. More specific device number studies can view the following files.

| # yum Install Kernel-doc

| #/usr/share/doc/kernel-doc-2.6.18/documentation/devices.txt

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　　Vii. Creating a Mount

　　1. Create mTAB

# Cat/net/etc/mtab

/dev/sdb1/ext3 RW 0 0

　　2. Create Fstab

# Cat/net/etc/fstab

/DEV/SDB1/EXT3 Default 1 1

　　Eight, install Grub

# chroot/net

# GRUB-INSTALL/DEV/SDB1

　　Note:

1. If you create a hard disk partition is not configured correctly, in the eighth step will be an error:

The File/boot/grub/stage1 not read correctly

2. After using the U disk to start, into the USB disk in the system, at this time we can use already

Installed command set, but at this time the file system is read-only, we can not vim,

Mount, and so on, you must use the following command to read and write the mount again:

# Mount-o REMOUNT,RW/

After the load is mounted, it is ready.

At this point, U disk Linux system Startup Disk production is completed, through the above methods, users can use U disk to start Linux system, no longer need to worry about accidentally deleted files into the system, and do not need to remove the hard drive to copy.