Oracle RAC SIG presentation tips

Yesterday I proudly presented a one hour training class about upgrading to Oracle 11.2 RAC at oracleracsig.org. This was the first time I presented using this facility and thought it might be useful for others to learn about the procedures and hopefully encourage other speakers to follow suit. It’s really straight forward and there is nothing to worry about! Especially if you are already familiar with webex, presenting should be a piece of cake. But I’m getting ahead of myself.

So how do you get to present?

So you don’t see any disks when trying to install ASM?

This is a post that highlights the difference between operating systems, but also the fact that sometime it is hard to break out of a habit once you got used to it. My background is that of a Linux enthusiast, even though I equally like Solaris and AIX but I have a little less exposure to those.

Background

I have recently been asked to look at RAC on SPARC, which I gladly did. The system I was given had the usual software stack for RAC at this customer’s site. It comprised of:

• Solaris 10 Update 9 64bit on SPARC
• EMC Power Path 5.1
• EMC VMAX storage – 10x10G LUNs for a specific performance test

The Power Path configuration has already been in place when I got the machine, and I was allocated /dev/emcpower2[0-9] for my ASM testing. For the experienced Linux user who relies on device-mapper-multipath, the Power Path naming convention can be a bit confusing at first. For reference, the pseudo devices we are interested in for ASM are created under /dev/rdsk/-the “raw” device directory for “character” based access rather than the block device in /dev/dsk/.  By default, the Power Path devices are called “emcpower”, followed by a number and a letter (in SPARC). An example would be /dev/rdsk/emcpower20c.

Compiling iozone for Solaris 10 on SPARC

I have started working with ZFS and its various ways of protecting disks from failure. It’s a low end setup at best, where a JBOD is used as an extension to a M-series server. Many JBODs come with SAS connectivity only, and no on-board intelligence so a host based solution has to be chosen to protect the lot from disk failures.

For Solaris, you can use ZFS amongst other solutions. Alternatively, ASM is a possibility. I couldn’t reproduce the exact setup, so I had to improvise. Still I wanted to find out how ZFS performs compared to ASM. For this purpose I used an EMC VMX and a Sun 5410 server which had 10 multipathed 10G LUNs presented to it via EMC Power Path 5.3.

To test the file system performance I decided to use both IOZone and Bonnie++. Bonnie++ is no problem, you can get it from Sun Freeware. Note that Oracle no longer produce the Companion CD, which leaves SunFreeware the only source for alternative packages.

Using Connection Manager to protect a database

I have known about Oracle’s connection manager for quite a while but never managed to use it in anger. In short there was no need to do so. Now however I have been asked to help in finding a solution to an interesting problem.

In summary, my customer is running DR and UAT in the same data centre. Now for technical reasons they rely on RMAN to refresh UAT, no array mirror splits on the SAN (which would be way faster!) possible. The requirement is to prevent an RMAN session with target=UAT and auxiliary=DR from overwriting the DR databases, all of which are RAC databases on 11.2.