Need information about the storage of my VPS

I use MobaXTerm to connect to my VPS using both SSH and FTP. Thanks to the software I also see the use of RAM/Storage/... of my VPS. By connecting I realize that I use 89% of the 40GB of my offer. So I decided to take the one above at 50GB. However once the change was made I only went down to 86% usage.

I would therefore like to succeed in understanding how to control the storage of my VPS and know where I am currently.

Here is the output of the df -h command. Unfortunately I don't really understand why /dev/sda1 only has 29GB. I don't really understand if in total I still have space or not on the 50GB. Namely that I use pterodactyl and therefore docker.


Filesystem      Size  Used Avail Use% Mounted on
tmpfs           833M  1.9M  831M   1% /run
/dev/sda1        29G   25G  4.1G  86% /
tmpfs           4.1G     0  4.1G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
/dev/sda15      105M  6.1M   99M   6% /boot/efi
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/d91d2cdb11bba83a6cb763e8e8d1474466935efc7fc6a5c6e244473c3f7d4abf/merged
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/3855868f555c118fbbbd10fe22d921ad08fc746f78f2a1e97614301d63a2cd80/merged
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/1818aecc365ee3aa3f892fbbaa3a155d2dbacc6c185fcbc7ba5fd7bfb7fd3545/merged
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/ead54eca740041d908bbd22f797511ea8e8797831248258cc39e78c035b7694b/merged
tmpfs           833M  4.0K  833M   1% /run/user/0
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/6be77edc9f670b93f76ee85d151d1d48b9b7f067234ba7d3a9ac5d0c4642aea6/merged
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/410c022362208240b7bfb6958ca96ccd404a56566bd52eb95b2df5f0b63f38c0/merged
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/ba40f77a29e78b056712cda937087d3ed57cdbd099e59e75e72faed06fb8e837/merged
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/f06902a97c9085d196515c34809e65a14444c68058f377c5588e7e01c2e42b41/merged
overlay          29G   25G  4.1G  86% /var/lib/docker/overlay2/d86b05e4c30cd7518a6e0cfc1a84cf521819f1aca0c38ef4cd7d6b4c393724c9/merged

Solution

What you need to look at is /dev/sda1 which has only 4.1 gb available out of the 29 total.

Filesystem|Total Size|Used|Available|Use%|MountPoint
/dev/sda1      29G    25G    4.1G    86%      /
                              ^
                              |
                             this is what you need to look at

If your provider told you that you have 50 gb on your server they either scammed you or forgot to give you 20 gb