Note: Installing Oracle 11gR1 on Ubuntu 8.10 Intrepid Ibex is now published.

After our last post about installing Oracle 11g on Ubuntu 7.10 (November, 6^th), and considering Ubuntu 8.04 LTS was released on April 21^st, I spent some time reviewing and putting together this new HOWTO for the installation.

Please note: I’ve used the x86 server version of Ubuntu 8.04, but the same steps should work without any problems for the Desktop version. Also notice that this whole procedure can easily take over six hours to complete, so don’t complain I didn’t warn you!

So, let’s get started, shall we?

Step One

Get the Ubuntu Linux 8.04 Hardy Heron (x86, 32-bit) image here, burn it, and install on any box you like. The only remark on the installation is that you should ask the installer to install an OpenSSH server at the end of the installation, since we’ll perform all the steps on this procedure remotely.

I’m not sure about the minimum requirements for the server, as, the last time I checked, running Oracle on Ubuntu is not officially supported by Oracle. In case you’re wondering, however, I’m using an x86 Pentium-like machine with 512M of RAM.

Step Two

Download Oracle 11g for Linux (x86, 32-bit).

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I’ve recently moved to Ubuntu Linux, and this post describes my attempt to play around with Oracle ASM on Ubuntu. For this demonstration, I used Oracle 11.1.0.6 on Gutsy Gibbon. I hope it will be useful to somebody out there.

Important Notice: What I describe below is among the worst thing you can ever do with ASM. You can use it to play around but never use it with anything other than test data. If you lose something because of me, you’ll be the only one to blame !

Question #1: How do you simulate a disk from a file?

(See here for more details.)

If you have a free partition or disk to be used as an ASM disk, just skip this step. If you don’t, you can create a file with the dd command and create a device that actually loops to the file with the losetup command.

Let’s assume you’ve created a directory named /asmdisks (and you have write access to it). Run the command below to create a file named disk1 that is 3GB in size:

$ dd if=/dev/zero of=/asmdisks/disk1 bs=1024k count=3072
3072+0 records in
3072+0 records out
3221225472 bytes (3.2 GB) copied, 80.9113 seconds, 39.8 MB/s

Once you’ve created the file, map it to a device named loopN in /dev. You can list the used loop devices with the losetup -a command.

Once you’ve made sure the one you plan to used is free, e.g. /dev/loop1, you can map the device to the file with the following commands (you have to be root) :

# losetup /dev/loop1 /asmdisks/disk1
# losetup -a
/dev/loop1: [0802]:7438407 (/asmdisks/disk1)

Question #2: How do you create an interface to the disk that is usable by ASM?

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I gave this talk at the UKOUG, and I have received a few requests to post the slides online. Instead of just posting the PowerPoint I took some time to give the presentation again (internally here at Pythian) and this time we recorded the session and we’re posting it here in a variety of formats. This is a bit of a departure from the typical Pythian Goodies, in that it is scripted, and there is a lot of content here in the whitepaper, but there hasn’t been a Goodie in a while so why not!

I’d love to hear from you, so please feel free to ask any follow-up questions to this post in the comments.

Abstract

Do I have enough memory? Why is my free memory so low? Am I swapping to disk? Can I increase my SGA (db cache) size? Can I add another instance to this server? Are my system resources used optimally? These are all questions that often haunt DBAs. This presentation is The Answer. It covers in detail the different types of memory, how to monitor memory, and how to optimally use it with Oracle. Multiple examples in the presentation demonstrate how certain actions on the database side cause different memory areas to be allocated and used on the OS side. Key underlying differences in operating systems approaches to managing memory will be highlighted, with special attention given to Linux, Solaris, and Windows. Using Linux as an example throughout, this presentation explains how to effectively use tools such as “top”, “vmstat” and “/proc/meminfo” to look into into a system’s allocation and use of memory.

Below you should see a flash video with me giving the session.

Download this presentation!
Powerpoint
IPod video (right-click and Save As . . .)
MP3 audio only

And below you will find the complete contents of the whitepaper. This is intended to be a good overall reference resource for how memory works in Oracle, using Linux as an example.

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Note: Installing Oracle 11gR1 on Ubuntu 8.10 Intrepid Ibex is now published.

After many requests from readers, I’ve put together new, revised version of the Oracle 11g on Ubuntu recipe. This new version is a little different than the first one published: it’s based on a bare-bones install of Ubuntu 7.10 (Gutsy Gibbon) server version instead of the desktop version. As an improvement, I’ve tried to pare down dependencies to a minimal set.

Your feedback is more than welcome — it’s the main reason why I wrote a new version of this HOWTO. I’ve also tested and repeated this procedure twice. Even so, it might still have problems, so please let me know so we can improve it ¹.

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It looks like the second public platform release for Oracle 11g is (surprise, surprise) Linux x86-64. Downloads are available on OTN.

As with previous Linux releases, 32-bit Oracle with a 32-bit OS and 64-bit Oracle with a 64-bit OS are supported, but 32-bit Oracle with a 64-bit OS is not.

Note also that sqlplus does not play well with SELinux under RHEL5; workarounds are to disable SELinux entirely, or to manually change the context of Oracle libraries to textrel_shlib_t. More details are in MetaLink note 454196.1 (login credentials required).

It seems Oracle 11g introduces a difference between count(*) and count(1). The way this happens is just the opposite of what I was thinking would happen. NB: I ran my test using “11.1.0.6 32bits” on Ubuntu Linux 7.04 (Feisty) which is not officially supported¹, and which has already lead me to some unexpected behaviors. If this difference with count() is really the 11g way and not buggy behavior related to the Ubuntu install, I’m glad to have found it.

Here’s what you can do to observe (or confirm or dispute) this.

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After weeks of not having the time I wanted for this, it’s finally done! Today, I installed RAC on Oracle Enterprise Linux 5 (OEL5), and I can tell you that there’s nothing exceptional about the process.

The only trouble I encountered had nothing directly to do with the installation. In order for the device rights to be assigned when RHEL5 or OEL5 start up, you have to create a file in /etc/udev/rules.d, but I have already spoken about that in my last post on the subject of raw devices.

Besides that, it’s all quite simple once 10g’s prerequisites are met. After an hour and a half, it was all wrapped up, at least for two nodes. I didn’t see anything revolutionary differences, but nonetheless there are some points worth mentioning.

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Note: Installing Oracle 11gR1 on Ubuntu 8.10 Intrepid Ibex is now published.

Note: I have now published “Installing Oracle 11g on Ubuntu Linux 7.10 (Gutsy Gibbon)”

Note: This page focuses on Ubuntu installs. Oracle has published a web page for successfully installing Linux on unsupported platforms that you may find helpful.

I come from a MySQL background, and I have been given the challenge of learning Oracle. I can’t just play around with our customers’ databases, but I remembered that Paul Vallée said that there is nothing wrong with learning on company time. So I decided to install my own Oracle database, which I’ll be free to destroy in every way I can think of… and of course, free to bring it back to life. Recovering from crashes will probably be the most difficult part of my adventures in the Oracle world, but let’s take one step at a time, shall we?

Now, onto Oracle 11g (beta 5) on Ubuntu 7.04 (Feisty Fawn). One little issue is that Ubuntu is unsupported by Oracle. So, through this text, we will trick the Oracle installer into thinking it’s actually running on a Red Hat box.

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