I recently did a re-sizing on the OS disk of my Ubuntu VM (increase from 30GB to 100GB). On the Azure portal everything looked fine but when I logged in the VM and did "df -h", the size of "/dev/sda1" is still 29GB. I have tried to deallocate and restart the instance many times but the resizing is still not reflected. I also tried "sudo fdisk" but it did not work and kept telling me I am out of range in terms of sectors. Also tried to umount the partition but could not do it because the "target is busy". Anyone experienced this problem before?