Step # 1: Rescan the SCSI Bus to Add a SCSI Device

A rescan can be issued by typing the following command:
echo "- - -" > /sys/class/scsi_host/host#/scan
fdisk -l
tail -f /var/log/message

Replace host# with actual value such as host0. You can find scsi_host value using the following command:
# ls /sys/class/scsi_host
Output:

host0

Now type the following to send a rescan request:
echo "- - -" > /sys/class/scsi_host/host0/scan
fdisk -l

Step # 2: Add disk on the logical volume group

fdisk /dev/sdb (with, n, p, w)
cat /proc/partitions
pvcreate /dev/sdb1
ls /sys/class/scsi_host
vgdisplay
vgextend VolGroup00 /dev/sdb1
vgdisplay
pvdisplay
lvdisplay
lvextend -L+300G /dev/VolGroup00/LogVol00
lvextend -L+299G /dev/VolGroup00/LogVol00
lvextend -L+100M /dev/VolGroup00/LogVol00
lvextend -L+50M /dev/VolGroup00/LogVol00
lvextend -L+10M /dev/VolGroup00/LogVol00
lvextend -L+1M /dev/VolGroup00/LogVol00
lvdisplay
resize2fs /dev/mapper/VolGroup00-LogVol00