If I try to update Fedora I have to less space, how can I free some space? Were are application installed?

Hello,

As other thread mentioned I'm not so familiar with Linux but I try to get further.

Here is my partition config:

• boot ext4 500 MiB
• home ext4 15 GiB (was 50 GiB)
• root ext4 10,80 GiB (Why 0,80 extra?)
• var ext4 38,20 GiB (was 4 GiB)
• Swap ext4 8 GiB (equal to memory)

A few things what I try to find out:

Question 1:
I try to upgrade fedora 31 to 32 with "sudo dnf upgrade", but than I got the message:
Quote:

The downloaded packages were saved in cache until the next successful transaction. You can remove cached packages by executing 'dnf clean packages'. Error: Transaction test error: installing package MariaDB-backup-debuginfo-10.4.15-1.fc31.x86_64 needs 151MB on the / filesystem Error Summary ------------- Disk Requirements: At least 151MB more space needed on the / filesystem.

My questions are:
This is downloaded in cache, at which cache? (If I run 'dnf clean packages', 610 files are removed.)
How can I solve this?

--

Question 2:
I have installed netbeans-11.2 first and later version 12. But now both are installed. So I want to remove version 11.2.
I have find out that these is installed in /u01/app/netbeans11-2.
If I try to unstall this with the uninstall script with: ./uninstall.sh, Than I get this error message:
Quote:

Configuring the installer... Searching for JVM on the system... Java SE Development Kit (JDK) was not found on this computer JDK 8 is required for installing the NetBeans IDE. Make sure that the JDK is properly installed and run installer again. You can specify valid JDK location using --javahome installer argument.

I try to find were the JDK is installed or the value of JAVA_HOME. But with echo $JAVA_HOME nothing is returned.
In /usr/lib/jvm I found:
rwxrwxrwx. 1 root root 26 Apr 22 17:44 java -> /etc/alternatives/java_sdk
lrwxrwxrwx. 1 root root 29 Apr 22 17:43 java-14 -> /etc/alternatives/java_sdk_14
lrwxrwxrwx. 1 root root 37 Apr 22 17:43 java-14-openjdk -> /etc/alternatives/java_sdk_14_openjdk
drwxr-xr-x. 7 root root 4096 Apr 22 17:43 java-14-openjdk-14.0.0.36-3.rolling.fc31.x86_64
lrwxrwxrwx. 1 root root 34 Apr 22 17:44 java-openjdk -> /etc/alternatives/java_sdk_openjdk
lrwxrwxrwx. 1 root root 21 Apr 22 17:44 jre -> /etc/alternatives/jre
lrwxrwxrwx. 1 root root 24 Apr 22 17:40 jre-14 -> /etc/alternatives/jre_14
lrwxrwxrwx. 1 root root 32 Apr 22 17:40 jre-14-openjdk -> /etc/alternatives/jre_14_openjdk
lrwxrwxrwx. 1 root root 47 Apr 9 2020 jre-14-openjdk-14.0.0.36-3.rolling.fc31.x86_64 -> java-14-openjdk-14.0.0.36-3.rolling.fc31.x86_64
lrwxrwxrwx. 1 root root 29 Apr 22 17:44 jre-openjdk -> /etc/alternatives/jre_openjdk

How can I find were the right Java is installed?

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Question 3:
I like to work with:

• Netbeans
• Eclipse
• Apache
• PHP
• MySQL/MariadB
• Joomla
• etc...

But what is the 'best' location to install these applications? I mean in windows you have Programm Files or Programm Files(86) or you can define you're own directory at the beginning of the installation process. With windows I have more the feeling that I can more steer the installation. Here with dnf it is installed somewere but I don't know if it is done in the home directory or /usr or /var. So I try to find out some structure.

And if I go through my home directory than I find there also something of Netbeans and other things and I'm asking myself did I or is here the application installed? Can I remove it? Or is it installed at /u01/app or /usr/... or /var/...

So I try to find way in Linux were are 'things' installed? And how can find out were these applications are installed? I have tried the find command but than I get a lot of hits sometimes.

I hope that someone can give me some advise in these.

Nico