MyLinuxTips

• From the dmesg output,  identify the device name under which the drive is known to the system. Sample messages for a 1 Gb flash disk being recognized as /dev/sdb:

Initializing USB Mass Storage driver…
scsi2 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 5
usb-storage: waiting for device to settle before scanning
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
Vendor: USB 2.0   Model: Flash Disk        Rev: 5.00
Type:   Direct-Access                      ANSI SCSI revision: 02
SCSI device sdb: 2043904 512-byte hdwr sectors (1046 MB)
sdb: Write Protect is off
sdb: Mode Sense: 0b 00 00 08
sdb: assuming drive cache: write through
SCSI device sdb: 2043904 512-byte hdwr sectors (1046 MB)
sdb: Write Protect is off
sdb: Mode Sense: 0b 00 00 08
sdb: assuming drive cache: write through
sdb: sdb1
sd 2:0:0:0: Attached scsi removable disk sdb
sd 2:0:0:0: Attached scsi generic sg1 type 0
usb-storage: device scan complete 

• Note: For the remainder of this article, we will assume this device name to be /dev/sdb. Make sure you adjust the device references in the following steps as per your local situation.
• At this point, the flash drive is likely to have been automatically mounted by the system. Make sure the flash drive is unmounted. E.g. in nautilus, by right-clicking on the icon for the drive and selecting Unmount Volume.

• Use fdisk to partition the flash drive as follows:
  
  • There is a  single partition.
  • This partition is numbered as 1.
  • Its partition type is set to ‘b‘ (W95 FAT32).
  • It is tagged as bootable.

  
  

• Format the partition created in the previous step as FAT:

mkdosfs /dev/sdb1

• Mount the partition:

mount /dev/sdb1 /mnt

• Copy the contents of /RedHat/isolinux/ from the first installation CD/DVD onto the flash drive, i.e. to /mnt.
  Note: the files isolinux.bin, boot.cat and TRANS.TBL are not needed and can thus be removed or deleted.
• Rename the configuration file:

cd /mnt/; mv isolinux.cfg syslinux.cfg

• Copy the installer’s initial RAM disk /RedHat/images/pxeboot/initrd.img from the first installation CD/DVD onto the flash drive, i.e. to /mnt.
• Optional step: To configure any boot settings, edit the syslinux.cfg on the USB flash drive. For example to configure the installation to use a kickstart file shared over NFS, specify the following:

linux ks=nfs:://ks.cfg

• Unmount the flash drive:

umount /dev/sdb1

• Make the USB flash drive bootable. The flash drive must be unmounted for this to work properly.

syslinux /dev/sdb1

• Mount the flash drive again:

mount /dev/sdb1 /mnt

• Install GRUB on the USB flash drive:

grub-install –root-directory=/mnt /dev/sdb

• Verify that the USB flash drive has a /boot/grub directory. If it does not, create the directory manually.
  

  cd /mnt
  mkdir -p boot/grub

• Create the grub.conf file. Below is a sample grub.conf:
  

  default=0
  timeout=5
  root (hd1,0)
  title Red Hat Enterprise Linux installer
  kernel /vmlinuz
  initrd /initrd.img

• Copy or confirm the created grub.conf file is on the /boot/grub/ directory of the USB flash drive.