Android Studio


Fedora install JDK (OpenJDK) 2

As we were setting up a machine that would be used for software development, we came to the need of installing a Java Development Kit (JDK).
There are two popular choices on the web between the OpenJDK and the Oracle JDK, we decided to go with the OpenJDK option which is a free and open source implementation of the Java Platform and it is part of the official Fedora repositories.

To install the OpenJDK along with all the needed libraries for development we used the following command:

sudo dnf install java-1.8.0-openjdk java-1.8.0-openjdk-devel;

On our GNU/Linux Fedora the installation folder of the JDK was /usr/lib/jvm/java-1.8.0-openjdk.

 


Fedora Configure Hardware Acceleration for the Android Emulator

While setting up Android Studio on a Fedora 27 x64, we got the following message from the Android Studio Setup Wizard:

We have detected that your system can run the Android emulator in an accelerated performance mode.
Linux-based systems support virtual machine acceleration through the KVM (Kernel-mode Virtual Machine) software package.

Search for install instructions for your particular Linux configuration (Android KVM Linux Installation) that KVM is enabled for faster Android emulator performance.

After going through the website mentioned in the message we noticed that there were no instructions for Fedora so we decided to write our own.

Below are the steps we followed to enable hardware acceleration for the Android emulator.

Step 1: Verify that your CPU has virtualization extensions.

Execute the following in a terminal:

egrep '^flags.*(vmx|svm)' /proc/cpuinfo;

if you get ANY output then it would mean that your CPU supports either VMX or SVM which is good.
If it does not print anything then the emulator will fall back to software virtualization, which is extremely slow.

Step 2: Install the virtualization packages

sudo dnf group install --with-optional virtualization;

Step 3: Start the service

sudo systemctl start libvirtd;

Step 4: Automatically start the service on boot:

sudo systemctl enable libvirtd;

Step 5: Verify that the kvm kernel modules were loaded

lsmod | grep kvm

If the above command does not print kvm_intel or kvm_amd, it would mean that KVM is not properly configured.


Android Studio – No space left on device 9

Recently we tried to install some packages from the Android SDK through Android Studio 3.0.1 and we got the error that the PC ran out of space while downloading the necessary packages and could not perform the operation.

Full Error Log:

To install:
- Google APIs Intel x86 Atom System Image (system-images;android-27;google_apis;x86)
Preparing "Install Google APIs Intel x86 Atom System Image (revision: 2)".
Downloading https://dl.google.com/android/repository/sys-img/google_apis/x86-27_r02.zip
An error occurred while preparing SDK package Google APIs Intel x86 Atom System Image: Cannot download 'https://dl.google.com/android/repository/sys-img/google_apis/x86-27_r02.zip': No space left on device
, response: 200 OK.
"Install Google APIs Intel x86 Atom System Image (revision: 2)" failed.
Failed packages:
- Google APIs Intel x86 Atom System Image (system-images;android-27;google_apis;x86)

Although the disk had a lot of free space, we got this error because the /tmp partition on our GNU/Linux Fedora 27 workstation was too small (~4GB).

$ df -h;
Filesystem Size Used Avail Use% Mounted on
devtmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 107M 3.8G 3% /dev/shm
tmpfs 3.9G 1.9M 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/mapper/fedora-root 50G 35G 12G 75% /
tmpfs 3.9G 2.1M 3.9G 1% /tmp
/dev/sdb1 477M 179M 269M 41% /boot
/dev/mapper/fedora-home 178G 37G 132G 22% /home
tmpfs 794M 16K 794M 1% /run/user/42
tmpfs 794M 9.2M 785M 2% /run/user/1000

/tmp was not explicitly set so it was automatically configured to have half of the size of the RAM.
We didn’t not want to change the download path for the Java environment (and hence Android Studio and Android SDK tools) as after leaving the tmpfs folder it could mean that we would have to manually maintain the new path and clean it up. So we ended up in temporarily increasing the size of /tmp partition which did the trick and the virtual device was installed successfully.

Solution – temporarily increase the size of the /tmp partition:

The command we used to increase the size of the /tmp partition on Fedora 27 was the following:

sudo mount -o remount,size=8G,noatime /tmp;

After executing we, it we immediately saw that the results were applied without the need for a restart or any other operation and we could proceed to use the PC as normal.

$ df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 89M 3.8G 3% /dev/shm
tmpfs 3.9G 1.9M 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/mapper/fedora-root 50G 35G 12G 75% /
tmpfs 8.0G 2.0M 8.0G 1% /tmp
/dev/sdb1 477M 179M 269M 41% /boot
/dev/mapper/fedora-home 178G 37G 132G 22% /home
tmpfs 794M 16K 794M 1% /run/user/42
tmpfs 794M 6.9M 787M 1% /run/user/1000

The information for tmpfs we got it from: https://wiki.archlinux.org/index.php/Tmpfs

Full Correct Execution Log:

To install:
- Google APIs Intel x86 Atom System Image (system-images;android-27;google_apis;x86)
Preparing "Install Google APIs Intel x86 Atom System Image (revision: 2)".
Downloading https://dl.google.com/android/repository/sys-img/google_apis/x86-27_r02.zip
"Install Google APIs Intel x86 Atom System Image (revision: 2)" ready.
Installing Google APIs Intel x86 Atom System Image in /home/xeirwn/Android/Sdk/system-images/android-27/google_apis/x86
"Install Google APIs Intel x86 Atom System Image (revision: 2)" complete.
"Install Google APIs Intel x86 Atom System Image (revision: 2)" finished.