Hello,
I am using a VM image provided by SAP on google cloud which runs on SUSE. The original configuration of the image was 36 GB, however when I created the image I increased it to 120 GB as I knew I will have to install few other components to it. When I ssh into the system I see that the /dev/sda1 is allocated only 36GB.

Code:
> df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs         13G     0   13G   0% /dev
tmpfs            13G     0   13G   0% /dev/shm
tmpfs            13G  9.7M   13G   1% /run
tmpfs            13G     0   13G   0% /sys/fs/cgroup
/dev/sda1        36G   33G  661M  99% /
tmpfs           2.6G     0  2.6G   0% /run/user/490
tmpfs           2.6G     0  2.6G   0% /run/user/1004
tmpfs           2.6G     0  2.6G   0% /run/user/1005
But the disksize available is 120GB.

Code:
> sudo lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0  120G  0 disk
└─sda1   8:1    0   36G  0 part /
How do I allocate more space from sda to sda1 ?