How to Resize root EBS on AWS Linux Instance

root@knowarth  [~] #  resize2fs /dev/xvda1

[root@knowarth ~ ] # df -hFilesystem Size Used Avail Use% Mounted on
/dev/xvda1 8G 3.7G 4.2G 45% /[root@knowarth ~ ] # fdisk -l

Disk /dev/xvda: 108.4 GB, 108447924224 bytes
255 heads, 63 sectors/track, 13184 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xeb6cffbe

[root@knowarth ~ ] # fdisk /dev/xvda
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').

Command (m for help): u
Changing display/entry units to sectors

Command (m for help): pDisk /dev/xvda: 108.4 GB, 108447924224 bytes
255 heads, 63 sectors/track, 13184 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xeb6cffbe

Command (m for help): d
Selected partition 1

Command (m for help): n
Command action
e extended
p primary partition (1 -4)
p
Partition number (1-4) : 1
First  sector (63-104857599, default  63) : 63
Last sector, +sectors or +size{K,M,G} (2048-104857599, default 104857599): [PRESS ENTER]
Using default value 104857599

Command (m for help): pDisk /dev/xvda: 108.4 GB, 108447924224 bytes
255 heads, 63 sectors/track, 13184 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xeb6cffbe

Command (m for help): a
Partition number (1-4): 1

Command (m for help): w
The partition table has been altered!Calling ioctl() to re-read partition table.WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@knowarth ~ ] # reboot

[root@knowarth  ~ ] #  resize2fs /dev/xvda1
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/xvda1 is mounted on /; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 4
Performing an on-line resize of /dev/xvda1 to 13106944 (4k) blocks.
The filesystem on /dev/xvda1 is now 13106944 blocks long.

[root@knowarth ~ ] # df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda1 100G 1.6G 93G 2% /
tmpfs 1.8G 0 1.8G 0% /dev/shm