Dolphin showing wrong free disk space

Have installed Kubuntu 20.04 on a new hard drive and before that have made a copy of the old home partition by cp /dev/sda5 /dev/sdb3. Whereby sdb3 was the new home partition on the new 1TB hard drive (now sda3).
At the installation of Kubuntu 20.04 I mounted sda3 as /home which is working fine (the old system was Kubuntu 18.04).

On the old drive the home partition was about 80GB, the new one has 320GB (from this only 45GB are used).

I have partitioned the new drive with KDE Partition Manager with a gpt Table. The old one had an ms-dos table. Now Dolphin file manager shows only about 25GB free disk space for the home partition (which was probably approximate the number of the old free drive space …

KDE Partition Manager displays the correct free space (but has a question mark icon on sda3, 2,1,4). What to do to make Dolphin showing up the right free disk space and being able to use it?

Solution 1:

You copied the file system when you ran cp /dev/sda5 /dev/sdb3. That means the file system is not aware the size has changed.

How to grow it depends on what filesystem you use. Run mount to show all filesystems and file system type.

If it's ext3/4, simply run sudo resize2fs /dev/sdb3 to resize it.