Inceass the Root Disk Size for Centos in Aws

Issue: Root Partition not scaled after EBS is resized.

Growpart called by cloud-init only works for kernels >3.8. Only newer kernels support changing the partition size of a mounted partition. When using an older kernel the resizing of the root partition happens in the initrd stage before the root partition is mounted and the subsequent cloud-init growpart run is a no-op.

#lsblk
NAME    MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda    202:0    0  30G  0 disk
└─xvda1 202:1    0   8G  0 part /
Perform the following command as root:

# yum install cloud-utils-growpart

# growpart /dev/xvda 1

# reboot
After the reboot:

# lsblk
NAME    MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda    202:0    0  30G  0 disk
└─xvda1 202:1    0  30G  0 part /