EXT4 Resize

If you have an EXT4 disk mounted that you need to resize, do this.

Create a disk like this;

sudo fdisk /dev/sdb (make partition)
mkfs -t ext4 /dev/sdb1 (make ext4)
mkdir /u01
mount /dev/sdb1 /u01

Then, if you increase the space, this will expand it on the OS

Operation	Command
Unmount the disk	umount /u01
Check it is removed on filesystem	df -h
Amend partition	fdisk /dev/sdb
Delete that partition	d
Recreate the partition with new limits	n, p, 1, defaults, w
Check Disk not mounted, unmount if so	df -h, umount /u01
Check with e2fsck (required before resize2fs resize)	e2fsck -f /dev/sdb1
Resize	resize2fs /dev/sdb1
Remount or reboot	mount /dev/sdb1 /u01