OOW 2015: my presentation

I don’t have an official OOW presentation in the conference this year. However, I am presenting a session at the Oak Table World 2015 event behind held concurrently with OOW 2015. My topic is “Exadata Database Machine Security” and I plan to review some of the newest updates to security for the Exadata Database Machine engineered system.

As the website indicates, the event is completely free and there is no pre-registration or enrollment required–just show up and come on in to hear some great speakers present on great topics. Hope to see you there on Monday, October 26, 2015!

unplumb (or unbinding) NICs on Linux

I’ve been quiet for a long time now, but this entry hopefully will shake the cobwebs off and get me back into the habit.

I recently had a need to “unplumb” (from Solaris fame) or make interfaces on Linux “disappear” from the ifconfig list. It could be that I don’t know how to completely deconfigure an interface, but I didn’t find any methods to unassign an IP address from a Linux Ethernet interface after it was assigned. You can take interfaces down (ifconfig eth3 down) and reconfigure them to assign different addresses, but not remove the address completely.

After many searches and finding nothing that matched my need, I turned to my fellow Oakies (thanks, Mark!) who turned up this post from 2 years ago that hinted at a solution. It is driver-specific which is not ideal, but that makes sense given what I’m trying to do.

Here’s the generic version of the solution:

echo "<interface_name>" > /sys/bus/pci/drivers/<driver_name>/unbind

Determining the driver_name is pretty simple: check the /etc/modprobe.conf file (on OEL/RHEL 5.x). In that file, you’ll find things like this:

...
alias eth0 igb
alias eth1 igb
alias eth2 igb
alias eth3 igb
...

These lines indicate that the Ethernet driver used on this system by eth[0-3] is the igb driver. Now that you know the driver name, the tricky part is figuring out what the driver wants you to use as the interface name. I’ll give a few examples (and I haven’t figured out the scientific way to determine what the driver expects short of reading source code).

For the bnx2 driver, you can use the relatively simple ethernet interface name, like this:

echo "eth2" > /sys/bus/pci/drivers/bnx2/unbind

For my test system, the igb driver doesn’t use the “simple” Ethernet interface name like the bnx2 driver does. Instead, when trying that, it gives an error that the interface doesn’t exist. Time to dig in a little deeper.

On this system, the igb directory looks like this:

# ls -l /sys/bus/pci/drivers/igb/


So, knowing that I have 4 interfaces on the system, I made the correlation to the 4 addresses that appear as symlinks in the driver’s directory and expect that they indicate the interface name. Checking a couple of those (each symlink references a directory), I see this:

# ls -Ll /sys/bus/pci/drivers/igb/0000:01:00.0


You can see the directory with name “net:<interface_name>” as a subdirectory in each listing above. This tells us which interface from /sys/bus/pci/drivers/igb/0000* corresponds with which of the Linux Ethernet interface names. From this, we can see that eth2 is really 0000:07:00.0. So, in order to unbind this interface such that it no longer appears in the “ifconfig -a” output, we run this command:

echo "0000:07:00.0" > /sys/bus/pci/drivers/igb/unbind

and then it no longer appears in the “ifconfig -a” output. If you wanted to make this permanent, you should comment out the corresponding line from /etc/modprobe.conf so that it won’t be configured at boot time. Using the echo command above takes effect immediately, but won’t persist through a reboot (after reboot, the interface will return) unless the /etc/modprobe.conf changes are made.

Now, hopefully the next blog post after this one won’t require 14 more months of preparation!

Collaborate 09: Don’t miss these sessions

Collaborate 09 starts on Sunday, May 3 (a few days from now!) in Orlando. I’ve been offline for several weeks (more on that later), but will be returning to the world of computers and technology in full force in Orlando. I’ve had a few inquiries about whether or not I’ll be at Collaborate, so I thought I’d resurrect my blog with a post about where I’ll be and some of the highlights I see at Collaborate 09.

First, where I’ll be presenting:

  • Monday, 10:45-11:45am, #301, “Avoiding Common RAC Problems”
  • Tuesday, 9:45am-12pm, #332, “Installing RAC From The Ground Up”
  • Wednesday, 9:45-10:45am, #121, “Troubleshooting Oracle Clusterware”

I’m also currently the President of the Oracle RAC Special Interest Group (RAC SIG). The RAC SIG is hosting several great sessions (I’m moderating a couple of these panels) at Collaborate 09 as well:

  • Sunday, 6-7:30pm, IOUG/SIG Welcome Reception (each SIG will have representatives there–this is open to all IOUG attendees)
  • Monday, 8-9am, RAC SIG Orientation
  • Tuesday, 12:15-1:15pm, RAC SIG Birds of a Feather
  • Tuesday, 4:30-5:30pm, RAC SIG Expert Panel
  • Wednesday, 4:30-5:30pm, RAC SIG Customer Panel (not in online scheduler at the moment, check again later)
  • Thursday, 8:30am-12pm, RAC Attack (University Session – Additional fee required)

The RAC SIG has also assembled this list of RAC-related sessions at Collaborate 09 to help you plan your conference agenda.

Be sure to set up your personal agenda using the agenda builder and add these sessions to your agenda. I think that if you have these in your agenda and details (like date or room assignments) change, you’ll be notified via email (not sure, but I think that’s how it works).

Also, you can follow @IOUG on Twitter (follow me too if you’d like) and that will help you find where the action is during the event next week. It’s going to be a great event and I look forward to seeing you there!

Exadata front and center

Just in case you were like me and did not tune in for Oracle’s quarterly earnings concall, there were some interesting highlights. As many of you (well, there aren’t that many of you that read this, but…) know, I’ve been very interested in Exadata since its announcement at Oracle OpenWorld 2008 in October. While some observed that Larry’s introduction keynote was rather brief, I didn’t take it as a sign of disinterest at all. According to the concall earlier this week, quite the opposite.

Here are some choice excerpts from the transcript that I find telling about the future of Exadata:

Larry Ellison:

“So, that’s looking back. Now looking forward, I think the most exciting product we’ve had in many, many years is our Exadata Database Server.”

“Exadata is 100% innovation on top of our very large and very strong database business. And the early results have been remarkable. Charles Phillips will go into a lot of detail but I’ll just throw a couple of numbers out there.

One of our customers, and Charles will describe this customer, one of our customers saw a 28x performance improvement over an existing Oracle database. Another customer saw a monthly aggregation drop from 4.5 hours just to 3 minutes.

When compared to Teradata, a competitive database machine that’s been in the market for a very, very long time, another customer saw that we were 6x faster than their existing Teradata application, when using Exadata versus Teradata.

Another customer saw a batch process fall from 8 hours to 30 minutes. Charles will go into more detail on all this, he will repeat those numbers, because I think they’re worth mentioning twice.”

Charles Phillips:

“So now just a few comments by area. On databases, Larry mentioned, we’re very excited about how the HP Oracle database machine is performing. The increases have just been stunning and so we are getting great feedback from our customers and the pipeline is the largest build I’ve ever seen in terms of a new product.

And as he mentioned, the numbers are just stunning. The major European retailer who reduced the batch processing time from 8 hours to 30 minutes did not believe the process had completed. We had to convince him that’s actually how it’s done.

And so, as Larry mentioned, this is the reminder that this is an internally developed technology in the midst of all the discussion of acquisitions. People forget that we’re actually spending $3.0 billion a year on research and development and this is why we do it.”

From these snippets, you can see that the top executives at Oracle are excited about Exadata. If you’re a techie (if you’re not, how’d you get to this blog?), you’ll probably already know about Kevin Closson’s popular blog on all things related to Oracle and storage. Kevin is giving a webcast next week on Exadata where we expect he’ll discuss some of the technical workings of the product–deeper than the overview information many of us have heard before. If you’re interested, I strongly encourage you to sign up for the event and attend. There is no better authority on Exadata than Kevin and this is a great opportunity!

Start Database Services automatically after instance startup

Those of us that have dealt with RAC environments for a while are familiar with the behavior of Oracle Services in an Oracle Cluster. Services are an essential component for managing workload in a RAC environment. If you’re not defining any non-default services in your RAC database, you’re making a mistake. To learn more about services, I strongly recommend reading the definitive whitepaper by Jeremy Schneider on the topic.

In an Oracle RAC cluster, services can be started, stopped, and relocated from one instance to another. However, if you have multiple services for your database, then it becomes difficult to start them at a cold start. Due to dependencies in Oracle Clusterware, Continue reading “Start Database Services automatically after instance startup”

Install to go-live, 3 days

This has been an interesting week, but not really that surprising.

I was called back to a previous client site where I had previously helped with some Oracle Application Server (10.1.2.2) post-install configuration. In that previous visit, I got oriented to the environment they use and the packaged application they were deploying. The packaged application uses JSP, Oracle Forms, and Oracle Reports (possibly also Discoverer). The deployment environment is all Microsoft Windows servers with two Oracle Application Server homes per application server since the vendor’s deployment requires that JSPs be deployed in a separate O_H from the Oracle Forms and Oracle Reports environment (that’s the first eyebrow-raise I did, but whatever). Continue reading “Install to go-live, 3 days”

RMOUG, Day 1, +1

RMOUG Day 2 has started, but there was so much great content yesterday, I don’t know if I’ll remember it all unless I write a few notes here on my learning.

My first session of the day was Graham Wood’s session on adaptive thresholds for monitoring in 11g. I didn’t know very much about these new methods for setting alerts, but they are certain to be useful. Some of the methods for adaptive thresholds were available in 10g, but many enhancements were made in 11g. Most importantly, the cyclic nature of workload has periods that can be automatically determined in 11g whereas in 10g, they had to be specified manually. Graham talked briefly about using DB Time and Average Active Sessions as important metrics for tuning, but for alerting, adaptive thresholds make the most sense. Setting a hard limit means that you will likely miss many issues. If your system is normally 10% utilized overnight, but spends all night at 60% utilization, you would like to know about it. However, during the daytime, if the system normally operates at 75% utilization, a hard alert limit at 80% would have miss the 6x utilization increase from the overnight hours. Adaptive thresholds wouldn’t miss the aberration and would alert you of the 60% utilization in the overnight period. That would allow you time to attempt to resolve the problem before daytime hours start.

Continue reading “RMOUG, Day 1, +1”

I bought my own server for $1.02 (USD!)

I’ve got a (always-growing) list of product, features or configurations that I’d like to experiment with, but sometimes they aren’t practical to test on my local virtual machines. So, I planned to roll a new virtual machine on the development ESX server that we had at my office. All was going along fine with the Linux installation (OEL5U2) screens until I got to the end where it starts actually installing. For whatever reason, our little server was sick (likely a storage problem) and it hung for hours.

Rather than debug the storage issue, I wanted to get on with my testing. I consulted my usual list of experts, and my friend Matt suggested that I spin up a machine in the Amazon EC2 cloud. I checked out the costs and it seemed fairly reasonable. VERY reasonable, actually. Since it was based on time (cost per hour the machine is running), I waited for a day or two until I could dedicate enough time to it and complete the testing in one sitting. Continue reading “I bought my own server for $1.02 (USD!)”

My Open World 2008 slides posted

I’ve been enjoying reading everyone’s OOW08 summaries and thoughts lately, which reminded me that I hadn’t posted the slides that I promised to put up. Unlike some presentations, my slides aren’t usually of too much use without the narrative that I spew in the session. That’s mostly because I try to make slides that have just enough information on them to remind me what to say–not to say it for me.

At any rate, I posted the slides for my three sessions. I’m not cool enough yet to use SlideShare–I’ll try that out in the future. Overall, I was pleased with how each of them went and was especially happy that I had more than 80 people at my Thursday at noon session.

If you attended one of my sessions or review the slides for one of them, please let me know your feedback either in comments below or send me a mail.

MSAD/OID/EUS/DB integration session room change, Weds at noon

My session scheduled for Wednesday at noon titled “Integrating Microsoft Active Directory and Oracle Internet Directory with Database Logins: Enterprise User Security” (S300044) has been moved to a larger room. It will now be in Marriott Salon 8, so if you were on the waiting list (there were quite a few of you!), you shouldn’t have any trouble finding a seat now as the room holds almost 900 people.

See you there–it should be a fun and informative session!