1GB Physical drive (sdb)
4 partitions (sdb1-sdb4)
- sdb4 is a 8e (LVM) managed partition.
- sdb4 starts where sdb3 ended and extends all the way to the end of the 1GB drive

Therefore I can not create any more partition on the drive (fdisk) and there is no more free space on the drive

Now, the disk was extended from its 1GB size to the size of 2GB...
meaning at the end of sdb4 is ~1GB of unallocated space.

Challenge: Get LVM to see the additional 1GB space so filesystems may be extended.