Oracloid Blog

Some time ago (yeah… shame on me) I mentioned having troubles running CRS on virtual machines using VMware Server. I found a solution a while ago and, since I promised to share if I find anything, now is the time.

First of all, I’m happy to admit that my observations regarding Windows hosted VM’s running better compare to Linux hosted were wrong. Indeed, how can Windows run faster than Linux?!

I used VMware Server 1.0.3. As host OS I used 64 bit Ubuntu or 32 bit Windows. Guest OS was 32 bit Oracle Enterprise Linux 4 (a la Larry Hat 4). As you could see later, I tried VMware Workstation 6.0 as well without any visible improvements. For shared storage I use either NFS exports from host OS (when using Ubuntu) or Openfiler when using Windows (even more CPU saturation).

To recall the problem… Virtual machine started to eat CPU like crazy when I start CRS inside virtual machine. Even without Oracle database - just starting CRS is enough. I could see that vmware-vmx process was consuming about 60% on one CPU core (AMD Athlon64 3800 X2). Inside virtual machine I could only see from time to time init.cssd in top and average CPU consumption jumping from 10% to 90% without any process in top that I could see. I tried strace on vmware-vmx processes in my host OS - could only see that most of the time is spent in poll system call.
Read more…

If you haven’t added Mary Ann Davidson’s blog to your RSS reader, you should at least check it out. It’s relatively low traffic but every post is quite long and full of interesting thoughts. Give it a shot.

Today, I’ve got a reminder about disclosing your bias and professional ethics. Not that it’s something completely new but after reading this post, you tend to re-evaluate some information sources and events.

PS: Hm… does this blog come back to life?

Just saw this this blog post and even spent 10 minutes watching the video demo.
In under one hour and could be as low as 30 minutes!?
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You have probably read it already on my Pythain group blog but I would like to repeat it here to make sure you, my dear reader, don’t get a chance to miss it.

I would like to announce that last weekend the BAAG party was born. I have finally managed to introduce Joing BAAG Form and the list of BAAG members which is tiny so far. I’m very excited about it and looking forward to this project.

If you are tired of observing troubleshooting by guessing day by day, by day, by day, by … — join the forces of BAAG party. We can make a difference together! See you there.

Guesswork - just say no!

You probably wouldn’t expect a technical Oracle post here. But I can’t call it Oracle blog without relevant content so here it goes. Let’s call it a late birthday present — my first post came on the 2nd of May, 2006 so it’s now one year, one month and one week old.

Today, purely by accident, I came across Metalink Note 413098.1 Extremely Poor RMAN Backup Performance to NFS After Upgrade to 10.2 on Solaris. It seems that it also affects HP-UX at least.

What I love the best from that note is the workaround for RAC environments:

Do not write backups to NFS at 10.2. Backup to tape using Oracle Secure Backup or an alternative Media Manager or backup to a local disk drive.

Oracle Secure Backup?!?! Does it mean mean it has fewer bugs? Nice ad.

I.e. if my backup infrastructure is based on NFS - I’m screwed. The advice basically turns into “do not backup your databases - it’s slow”. Where are the other workarounds like stay on 10.1 or 9i? “Don’t use big databases” would be just as appropriate.

If I have time, I’m going to test it on Linux but if someone has interest - benchmark backups from 10.1. and 10.2 on NFS and let us know. Better yet, run it through strace and check the system calls.

I have already blogged about it in the Pythian blog but I can’t refrain from mentioning it here in case you, my dear reader, didn’t get the message.

The names of the speakers (except maybe one whose last name starts with “G”) will tell you everything about quality of the content. However, you should not miss another part (and arguably the best) of this gathering. Hint - it has something to do with consumption of fine quality liquids.

Ta-da-a-a-a:
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If you are like me and somehow missed it at that time…
Must see.
Click on Bajillio screen-cast.
Oh… make sure your browser is AJAX-y enough!
I can’t stop… I can’t stop…

sqlplus /nolog @oracloid_web_site.sql

I.e. like SQL Server, for example. Set SERIALIZABLE parameter to TRUE and you get readers blocking writers. Dream of any Oracle DBA.

It seems that this parameter was documented in Oracle 7 documentation. Oracle 8i and 9i migration manuals say that it should not be used anymore and setting it to true is not supported. However, the parameter is still there in 9i and should still work.

10g has finally moved it to underscore parameter _serializable.

Interesting results from Google.

The first one references 42. Well, nothing surprising.

Next comes UKOUG event “Applications Unlimited Tour”. Unfortunately, it’s not really my area. I will have to change my profile it seems.

Oracle-L comes third. Again no surprise here.

Later we can see Doug’s flying Guinness story (not that you believe it, right?) as well as its replicas through feed aggregators.

So I find those results somewhat poor. I will have to make sure that more relevant contents is delivered.

UKOUG 2006 is over and I was planning to finally provide a bit more details about it especially now when wireless internet is usable - during the conference there were way too many people connected and it was difficult to get in. It’s really nice that they left a Wi-Fi access point working after conference closing.

While sitting around “Oak” Table (or how it’s called this year - Bloak table), I got a reminder that today is the last day to send IOUG abstracts. Since I planned to submit an abstract there - I rushed in and filled out two proposals based on responses I’ve got from my UKOUG presentations.

One abstract is about block change tracking internals. I saw that people were interested and Jonathan Lewis even mentioned it on his blog. So I thought that if this sir enjoyed it then others must be interested as well. I will probably redesign it a bit and remove some details but cover few more things that are unknown so far. Thanks to Tanel’s presentation on advanced research techniques, I have few ideas where to look now.

The second presentation will be (if accepted) on Extensibility of Grid Control. I saw that there was interest but I packed way too much in the presentation and rushed through it. So my plan is to cut some bits from it and organize a demo instead. I learned quite a bit from my first presenting experience so next time I should be even better. ;-)

Now the most important message of this post… I know the story behind this picture taken by the Hubble telescope. :-) Do you?
I’ll give you a hint - it’s a member of the OakTable Network on this picture - nothing to do with Uranus. By the way, Anjo Kolk is a very nice and entertaining guy as well as bunch of others I’ve met here at UKOUG. If you really want to know the secret of that picture - ask Anjo. I’m sure he’ll be happy to provide some insightful details.

By the way, he had quite interesting presentation “CPU Stories” and showed how to decide between faster CPU’s or more CPU’s. Actually, I’m really impressed that he was able to deliver it so well after such a long night (again!).

Since I started to speak about the last night, I can tell you that it was very entertaining and lots of fun. I collected quite a few nice photos and should post soon. Interesting fact is that this morning everyone (except me) knew that I went to bed at 5:20. How come? I’ll go and check if there is a hidden camera in my room. To get you guys jealous - I’m going to a nice Indian restaurant today. :-P

Here is another detail from the evening. The name of this beautiful detail is Hana.

Hana, you promised to read my blog. The picture of you that we have is really poor in quality. Please send us a good one! Me and Anjo are looking forward to it!

PS: Hm… is my darling reading this blog?