Implementing Linux native multipathing or DM-MPIO together with EMC PowerPath

puzzle

Guest Post

I’m delighted to say that this is another guest post from my good friend Nate Fuzi, who performs the same role as me for Violin but is based in the US instead of EMEA. Because he is American, Nate thinks that scones are called “biscuits”, that chips are called “fries” and that there is nothing – *nothing* – that cannot be improved with the simple addition of bacon. Clearly, something is fundamentally wrong with him (more...)

Using the Oracle Grid Infrastructure Agents for GoldenGate on Oracle restart

I was testing Oracle Goldengate on a non-clustered Oracle 12.1.0.2 database with ASM. With ASM, you need to have the grid infrastructure installed. The cluster ware for the single node install is called ‘oracle restart’.

The most convenient way to have Goldengate running at startup that I could find, was using the Oracle Grid Infrastructure Agents. These agents are not installed by default, you need to download these from the Oracle Technology (more...)

MySQL bind-address

While I try to keep things simple, sometimes eliminating options and explanations comes back to haunt me. After posting how to open a Fedora firewall port for a LAMP stack, somebody got trapped by my instructions for installing MySQL on Fedora. They got stuck because they had the following setting in their my.cnf file:

bind-address=localhost.localdomain

I’d suggested using that bind-address value for a DHCP VMware Fedora installation in Step #7. I was trying (more...)

Open Fedora Port 80

After installing the LAMP stack on Fedora, you need to open port 80 in the Firewall to access the PHP programs on the Fedora instance from external servers. You can open a firewall port by launching the firewall-config application as the root user with the following syntax:

firewall-config

The firewall-config utility opens the following dialog message:

FedoraFirewall1

Click on the Ports tab, and you’ll see the following:

FedoraFirewall2

Click on Add button to add a port (more...)

Fedora Install LAMP

My students wanted an extra credit assignment, so I thought a LAMP configuration and test would be appropriate. The only problem was I hadn’t added it to their course VMware instance. So, here are the instructions to install Apache2, PHP, and MySQLi for a complete LAMP stack.

The post builds on my Fedora Install of MySQL and MySQL Workbench on Fedora posts from last year. It also presumes that you’ve installed a studentdb database but (more...)

Oracle Linux 7.1 Preinstall Packages available for 11gR2 and 12cR1

Every so often I have a nose around the contents of the Oracle Linux public yum repositories and guess what I found in the OL7.1 base and OL7 latest repositories.

Yeeeeeaaaaahhhhhh!

The datestamps suggest they’ve been around since the 5th February, but I think these only became available with the release of OL7.1.

(more...)

Oracle system V shared memory indicated deleted

This article is written with examples taken from an (virtualised) Oracle Linux 6u6 X86_64 operating system, and Oracle database version 12.1.0.2.1. However, I think the same behaviour is true for Oracle 11 and 10 and earlier versions.

Probably most readers of this blog are aware that a “map” of mapped memory for a process exists for every process in /proc, in a pseudo file called “maps”. If I want to look (more...)

Docker – Take Two – Starting From Windows with Linux VM as Docker Host

My first attempt with Docker was from my Windows host machine using boot2docker, as described in this article: https://technology.amis.nl/2015/03/15/my-first-steps-with-docker-starting-from-windows-as-the-host/. Boot2docker is a great tool for being able to work with Docker on a Windows machine. However, I ran into limitations – such as not being able to create containers with the GUI applications running in them. Besides, Linux seems to be – for now at least – the more natural environment for Docker. (more...)

My First Steps with Docker – starting from Windows as the Host

After reading quite a bit about Docker – especially the great write up by Mark Nelson (Getting to know Docker – a better way to do virtualization?) I believe it is more than about time for me to delve a little further into Docker. Following Edwin Biemond’s lead, I have dabbled quite a bit in Vagrant and Puppet and had quite satisfying results. The attraction of Docker – the even leaner way of (more...)

Darwin-IT 2015-03-13 11:50:00

I have several Virtual Machines for our Virtual Course Environments. From time to time, I do an upgrade of the Oracle Linux version. But with every upgrade, Oracle Linux leaves the old kernel files. And in time the root disk is cluttered up. So I want to remove the old kernels. With a little googling, I came up with a discussion thread in Oracle Communities: Oracle Linux Remove Old Kernels (Archived by now).

To me (more...)

enabling hardware acceleration for Android SDK emulator on Linux

When using the Android SDK for testing mobile applications (for instance, created with MAF, Mobile Application Framework), you can utilize the GPU for hardware acceleration on the Windows platform. This will greatly improve the performance of the emulator. To be able to use the acceleration, you’ll need to install a separate package called Intel x86 Emulator Accelerator (HAXM installer).

Android SDK Manager Android SDK Manager

If you’re on the Linux platform, you notice that the Status is  “Not (more...)

Understanding enhancements to block cleanouts in Exadata part 2

In part 1 of the series I tried to explain (probably a bit too verbose when it came to session statistics) what the effect is of delayed block cleanout and buffered I/O. In the final example the “dirty” blocks on disk have been cleaned out in the buffer cache, greatly reducing the amount of work to be done when reading them.

Catching up with now, and direct path reads. You probably noticed that the migration (more...)

Understanding enhancements to block cleanouts in Exadata part 1

Travel time is writing time and I have the perfect setting for a techie post. Actually I got quite excited about the subject causing the article to get a bit longer than initially anticipated. In this part you can read about block cleanouts when using buffered I/O. The next part will show how this works using direct path reads and Smart Scans.

The article ultimately aims at describing the enhancements Exadata brings to the table (more...)

What happens in ASM if usable_file_mb is negative and you lose a failgroup

Having read the excellent post “Demystifying ASM REQUIRED_MIRROR_FREE_MB and USABLE_FILE_MB” again by Harald von Breederode I wanted to see what happens if you create a setup where your usable_file_mb is negative and you actually have to rebalance after a fatal failgroup error. I am using 12.1.0.2.0 on Oracle Linux 6.6/UEK3 in a KVM in case anyone is interested. I/O times aren’t stellar on that environment. It’s Oracle Restart, (more...)

Diagnostic-Code: SMTP; 550 host unknown

When we’re trying to send mail to localdomain through mailx from linux box. It says “Diagnostic-Code: SMTP; 550 host unknown”  and mail not sent.

Solution :

Edit sendmail.cf

# “Smart” relay host (may be null)
DS[10.x.x.xx]

restart the sendmail service and send the mail is successful

10.x.x.xx — mailbox server

 

 

 

 


Quick diff for two pieces of text in vim

Sometimes you need to see the difference between two pieces of console output. When I research, this can be two stacktraces, but also /proc//maps and smaps output; really anything. Of course, there’s diff, but the diff output is not very visual. Also, diff doesn’t do diffing between more than two files.

This can be done reasonably simple in vim. Here’s how to do that:
1. start vi; vi
2. do a vertical split using a (more...)

RHEL6 udev and EMC PowerPath

I’m working on Oracle database migration project where customer have chosen commodity x86 hardware with RHEL6 and EMC storage.

I’ve done many similar installations in the past and I always used the native MPIO in Linux (DM-Multipath) to load balance and failover I/O paths. This time however I’ve got EMC PowerPath doing the load balance and failover and got the native MPIO disabled. From my point of view it’s the same, whether I’ll be using (more...)

runInstaller fails at CreateOUIProcess with permission denied

Just a short post on a problem I encountered recently.

I had to install 11.2 GI and right after running the installer I got a message saying permission denied. Below is the exact error:

[oracle@testdb grid]$ ./runInstaller -silent -showProgress -waitforcompletion -responseFile /u01/software/grid/response/grid_install_20140114.rsp
Starting Oracle Universal Installer...

Checking Temp space: must be greater than 120 MB.   Actual 7507 MB    Passed
Checking swap space: must be greater than 150 MB.   Actual 8191 MB     (more...)

Installing Oracle 12.1.0.2 RAC on Oracle Linux 7-part 2

In the first part of the article series you could read how a kickstart file made the installation of Oracle Linux 7 a lot more bearable. In this part of the series it’s all about configuring the operating system. The installation of Grid Infrastructure and the Oracle database is for another set of posts.

There are quite some differences between Oracle Linux 6 and 7

To me the transition from Oracle Linux 6 to 7 (more...)

Installing Oracle 12.1.0.2 RAC on Oracle Linux 7-part 1

Now that 12.1.0.2 is certified on RedHat Linux 7 and spin-off environments it’s time to test the installation of RAC on such a system.

The installation of the OS is different from Oracle Linux 5 and 6-with these distributions was very straight forward how to install the operating system the method has changed significantly in release 7. I won’t cover the complete installation here, as always Tim Hall was quicker than me, (more...)