Command-Line Partitioning – Understanding the Output of df -h Command

command linefilesystempartitioning

I would like you to help me understand the output of df -h below:

udev            7,8G     0  7,8G   0% /dev
tmpfs           1,6G  1,7M  1,6G   1% /run
/dev/sda3       229G   68G  150G  32% /
tmpfs           7,9G  211M  7,6G   3% /dev/shm
tmpfs           5,0M  4,0K  5,0M   1% /run/lock
tmpfs           7,9G     0  7,9G   0% /sys/fs/cgroup
/dev/loop1       84M   84M     0 100% /snap/core/3748
/dev/loop0      160M  160M     0 100% /snap/spotify/5
cgmfs           100K     0  100K   0% /run/cgmanager/fs
tmpfs           1,6G   68K  1,6G   1% /run/user/1000

I would like to understand what exactly are the udev, tmpfs and /dev/loop partitions.

I am wondering if they are some sort of 'leftoveres' after my Virtual Machines in Virtual Box.

I had a few virtual machines with 8GB in size but I have removed them and I still see there are some partitions that are taking quite a lot of space.

  • Are they related to Virtual Box?
  • Is it safe to remove those partitions?

Best Answer

You have only one actual partition /dev/sda3.

You should not touch the udev and tmpfs partitions.

  • tmpfs is a virtual memory filesystem based on your RAM
  • udev supplies Dynamic device management using virtual files

More info regarding udev and tmpfs you can find in this answer.

  • /dev/loop partitions are a mounted snap-file which is based on SquashFS read-only file system

You can check what is the content of /snap/core/3748 and /snap/spotify/5 folders.
Anyway - those are very small files (160M and 84M) - so removing them won't save much disk space.

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