Dizwell Informatics

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Atlas – Installing Oracle on Fedora 23+

1.0 Introduction

Fedora is the Linux distro that Linus Torvalds uses (allegedly), so it’s a serious contender for your desktop. It is curated by Red Hat and is used by them as a ‘preview’ of their eventual Enterprise Server releases. It thus tends to be used as a ‘guinea pig platform’ -new technologies are introduced to it several years before they turn up in Red Hat proper. That makes Fedora rather experimental, quite cutting edge -and just a little bit unstable or ‘risky’. It nevertheless runs Oracle 12c perfectly well, for the most part.

Atlas (and Oracle 12c!) runs fine on any Fedora version from 23 upwards -but a specific issue arises in Fedora 25. That release marks the point at which Fedora switched to using Wayland by default (instead of X.org) as its display technology. In VirtualBox virtual machines, this causes display problems which prevent Atlas running. If you explicitly select to use the X.org display server, however, these problems go away. See Section 4 below for more details. A further specific problem arises in Fedora 26, which makes it impossible to create or run a database unless you do some tricksy finagling of the Oracle linking process. See Section 7 below for more details: it basically requires you to perform a software-only install and run a subsequent Atlas-created script to trick the Oracle software into behaving itself.

As is the case with all Atlas/Oracle installs, your server needs to be built with at least 5GB RAM and at least a 40GB hard disk; you must additionally ensure you have installed wmctrl or xdotool before attempting to launch Atlas.

Please watch the generic Atlas videos here, here and here to get an idea of how Atlas works in general. The generic documentation (including those videos) are available from this page. Below are Fedora-specific notes.

2.0 What’s been tested?

  • Fedora 23, 24, 25, 26 and 27

Please note that installation procedures for version 26 and 27 are very different from what happens in any of the other listed versions (see Section 7 below for the specifics).

3.0 Operating System media

Fedora is mainly available in Workstation and Server flavours: Atlas will assume you’re using the Workstation version (because the Server one lacks a GUI).

A 1.3GB Live DVD Installation media is available to download from the Fedora website.

A much smaller ‘net install’ CD is also available, but using it then means a lot of software has to be downloaded from the Internet during the installation, so the whole process is probably much slower than using the full-strength DVD.

Remember that those specific links above were valid as at January 7th 2017. Check the Fedora website to see the latest versions available at any time.

4.0 Operating System installation issues

There are no major deviations from the ‘accept the defaults’ approach when installing the operating system.

One minor one: when I am creating myself as the non-root user, I nevertheless check the Make this user administrator option:

This isn’t essential, but it makes it possible for me to type sudo -i to become root (which merely involves typing my own password), which is a bit safer than the alternative ‘su – root’ approach (which requires you know the root password).

5.0 Running Atlas

The major issue I had in running Atlas on Fedora of any sort simply arises from the fact that when Fedora runs on a VirtualBox virtual machine, it only offers a maximum screen resolution of 1024 x 768, which is not enough to allow Atlas to run. This can be fixed by issuing the following commands (as root):

dnf -y update kernel*

Wait for the PC to come back up, and then as root once more issue these commands:

dnf -y install kernel-devel dkms

Once that lot is installed, click to install the guest additions and either click on the option to auto-run the Additions installer, or (again as root) use these commands to run the installer manually:

sh /run/media/<username>/<VBOXADDITIONS_version>/VBoxLinuxAdditions.run

However, doing things this way causes a lot of new software to be installed, such that you are no longer working on a ‘clean’ distro at the point that you run Atlas. It nevertheless works OK, but if you could avoid installing stuff onto your clean distro, it would be good to do so.

Additionally, note that Fedora 25 uses the Wayland display server by default: it doesn’t work well once you install the VirtualBox guest additions (merely triggering constant requests to login and never actually succeeding in doing so). You can avoid that by specifically selecting to use X.org on the login screen:

Only then does the login succeed. This may obviously change over time as VirtualBox brings out new releases of their software that works better with Wayland, but it’s something to watch out for at the time of writing.

To be honest, I think a simpler approach is simply to switch virtualization platforms entirely: Fedora on VMware Workstation (or Player) runs at 1280 x 768 the moment you log on. It also offers plenty of other hi-res screen resolutions without the need to install anything, all of which are good enough to allow Atlas to run properly.

Note that Atlas’ attempts to automatically resize terminal windows will fail when Wayland is in use, though. Regardless of virtualization platform, therefore, I would strongly recommend that you stick to using X.org at this point: you can always switch back to Wayland once Atlas has run and Oracle has been installed successfully.

Both wmctrl and xdotool are available for Fedora from the standard repositories, and one or other of them should be installed before attempting to run Atlas. The relevant command, run as root, would be:

dnf install wmctrl

Additionally, I would recommend altering the default font size used in the terminal: it starts out at 12-point HUGE! Instead, select Edit > Profile Preferences, switch on the Custom font option and change the font size down to 10 or even 9-point:

Once you have the screen resolution high enough, X.org in use, wmctrl/xdotool installed and the font-size reduced a bit, you’re good to run Atlas, without further drama.

6.0 Installing Oracle 12c on Fedora 23 – 25

Please note the separarate installation instructions for Fedora 26 in Section 7.0 below.

No issues arise during the Oracle installation itself, except that you are told your ‘environment does not meet minimum requirements’. This warning can be ignored.

In consequence of ignoring that warning, you are not subjected to further warnings about missing prerequisites: you go immediately to a summary screen with an [Install] option that kicks off the installation process.

There are no compilation errors raised during the installation’s linking phase.

As a result of there being no linking errors, an atlas-postinstall.sh script is created in the oracle user’s Documents directory. This can be run once the linking phase is complete (or after the entire installation, including database creation, completes), if you would like to do so. Running it is entirely optional.

7.0 Installing Oracle 12c on Fedora 26

Fedora 26 ships with a version of glibc which is incompatible with the software Oracle supplies (and with lots of other software, too!). This means that whilst a default installation of Oracle 12c Release 1 or 2 would appear to compile properly, the database creation stage will fail completely: the progress bar fails to increment beyond about 2%, no matter how long you leave it. Accordingly, it is impossible to do a default Oracle 12c installation on Fedora 26. Instead, Atlas writes a re-compilation step into its atlas-postinstall.sh script, created in the oracle user’s Documents directory. This means that, on Fedora 26 alone, running the atlas-postinstall.sh script is not optional. You can’t get a database running until you run it!

Putting it simply, therefore, on Fedora 26 you uniquely do the following:

  • Run the Oracle installer normally
  • But select to do a ‘Software Only install’ when given the option
  • Click through the rest of the installer option screens, accepting all defaults
  • Run the root scripts when prompted
  • Then run the ~/Documents/atlas-postinstall.sh script

The post-install script does the following four things:

  1. Delete all Oracle-supplied libc* libraries from within the ORACLE_HOME/lib/stubs directory
  2. Recompiles all binaries
  3. Starts a default listener
  4. Creates a database, with SYS and SYSTEM passwords set to “oracle”

Here is a screenshot showing me running the post-install script:

You can see that it first mentions ‘writing relink log to…’ as the re-compilation process gets underway. Then it creates a default listener. After that, the script will output dire-looking warnings about SYS and SYSTEM passwords not being complex enough. These are merely warnings, however, and can be successfully ignored. They mean that your database gets created with admin password of “oracle” …which is, indeed, pathetically insecure, but at least memorable!

After that, the script will spit out a progress indicator, as follows:

Copying database files
1% complete
2% complete
18% complete
33% complete
Creating and starting Oracle instance
35% complete
40% complete
44% complete
49% complete
50% complete
53% complete
55% complete
Completing Database Creation
56% complete
57% complete
58% complete
62% complete
65% complete
66% complete
Executing Post Configuration Actions
100% complete
Look at the log file "/u01/app/oracle/cfgtoollogs/dbca/orcl/orcl.log" for further details.

Be warned that there is a very long wait between the 2% line and anything else! But if you have patience, it will get to the 18% and 33% lines eventually 🙂