linux (rhel, ubuntu) disk resize w/lvm template

Note: for dummmies there is a parted live dvd

RESCAN discs

prereq for online...

Linux, when adding a new disc

grep mpt /sys/class/scsi_host/host?/proc_name   #find host0 or other
find /sys -iname 'scan' | xargs -i{}  echo "- - -" > {}

Linux, when resizing existing disc

find /sys/class -iname 'rescan' | xargs -i{}  echo 1 > {}
find /sys/block -iname 'rescan' | xargs -i{}  echo 1 > {}

Adding new disk (Ubuntu)

fdisk /dev/sdb
    - recreate  (n)
    - set type (t) 8e (LinuxLVM)
pvcreate /dev/sdb1
vgextend ubuntu-vg /dev/sdb1
lvextend /dev/ubuntu-vg/root /dev/sdb1
resize2fs /dev/ubuntu-vg/root

Adding new disk (Centos)

fdisk /dev/sdb
    - recreate  (n)
    - set type (t) 8e (LinuxLVM)
pvcreate /dev/sdb1
vgextend VolGroup /dev/sdb1
lvextend /dev/mapper/VolGroup-lv_root /dev/sdb1
resize2fs /dev/mapper/VolGroup-lv_root /dev/sdb1

Extending the existing disk (RHEL)

yum install partprobe
#extend disk (virtually)
fdisk /dev/sda
- delete old partition (d)
- recreate  (n)
- set type (t) 8e (LinuxLVM)
#reboot or partprobe -s (if works)
pvresize /dev/sda2                          #no vgexted needed
lvextend -l +100%FREE /dev/VolGroup/lv_root
resize2fs /dev/VolGroup/lv_root