Sunday Jul 23, 2006

Does Wikipedia Suck?

Here is an interesting podcast or you can read a related article the author Jaron Lanier doesn't think much of wikipedia - his bio is on wikipedia.

To put it in a nutshell this colourful podcast raises some really good reasons why a collection of differing points of view can be far more useful than a single source. I found this more interesting than the recent wikipedia vs britannica debate.

[ T: ]

Friday Feb 17, 2006

Linux port to sun4v booted

It only been 8 days since the project was announced Now Dave has a machine booting.

[ T: ]

Thursday Feb 16, 2006

Economics of PC Storage part 2 - Hard Disks

I mentioned on the OpenSolaris site that commercial NAS devices charge between $1.60 to $3.00 per GigaByte without redundancy. That is 0.33 to 0.62 GigaBytes per dollar. From two web sites I got prices in January 2006 for 30 hard drives.


A more interesting way to measure Hard Disk value is GigaBytes per Dollar


Assuming that the GB per $ performance of hard drives can be represented as a quadratic we get
the red dotted line.

lm(formula = Size/Price ~ Size + I(Size\^2), data = mytable)

     Min       1Q   Median       3Q      Max
-0.36294 -0.14051  0.02323  0.13648  0.38674

              Estimate Std. Error t value Pr(>|t|)
(Intercept)  6.514e-01  1.517e-01   4.295 0.000202 \*\*\*
Size         1.173e-02  1.169e-03  10.030 1.33e-10 \*\*\*
I(Size\^2)   -2.052e-05  2.030e-06 -10.107 1.13e-10 \*\*\*
Signif. codes:  0 '\*\*\*' 0.001 '\*\*' 0.01 '\*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 0.1907 on 27 degrees of freedom
Multiple R-Squared: 0.7923,     Adjusted R-squared: 0.7769
F-statistic:  51.5 on 2 and 27 DF,  p-value: 6.093e-10

Solving the quadratic we get the best price performing hard drive would  be 286GB, sadly nobody makes such a drive but by eyeballing the graph the sweet spot is between 250GB to 320GB with a price performance above 2GB per dollar. Giving us a reasonable margin to build our OpenSolaris Appliance and still beat the comercial products 0.33 to 0.62 GigaBytes per dollar.

[ T: ]

Tuesday Feb 14, 2006

The Economics of PC Storage part 1

Talking to folks about building a new home computer after the initial tricky but quickly resolved problem of which CPU do you want to use. Comes storage, I'm talking internal hard drives. There is so much choice in the marketplace at the moment. Do you choose PATA (new name for ATA) or SATA? What about MTBF, power consumption, noise etc. What size is best 80GB up to 500GB all seem plausible sizes but where is the sweet spot?

So my goal is have fun putting together an OpenSolaris  high performance low cost NAS appliance and finding way to measure to see if it really is high performance and low cost.

Economics of PC Storage part 2 - Hard Disks

[ T: ]

Friday Feb 10, 2006

"Putting a large number of these medium-sized cores on a chip is not optimal." - FUD

This comment came from a blog I'm not sure if it was deliberate FUD or the author was just not aware that in today's world the old rules of thumb are no longer relevant.

Today almost all business applications are either multi-threaded or multi-process [firefox, apache, oracle, mysql, postgress, java, ...] So you are more interested in the performance of many threads than a single thread. The old thinking is cache misses are bad do anything to reduce cache misses build a bigger cache, keep other cores away from this cache because when we have a cache miss the processor will stall and that will reduce performance. The real problem is not cache misses but processor stalls. The T1 has 4 hardware threads per core so when we have a cache miss it can work on another thread, the processor doesn't stall. So does the T1 have more cache misses than other processors – maybe, does it reduce the performance of the T1 – No. More theory here more practice here.

[ T: NiagaraCMT CoolThreads CPU ]

Wednesday Feb 08, 2006

Secret Linux port to sun4v

David Miller tells all here.

[ T: ]

Free WiFi

A new piece of hardware appeared on a local street light pole.
internet on a stick
It looks to be part of google's plan to setup free WiFi. I went looking for a google wifi faq but couldn't find one, but I did find this blog. The first questions that come to mind is will it be better than DSL or cable, what bandwidth is available both up and down. What are the economics of this for google and for the city. Will people throw away their mobile phones and use skype devices while in silicon valley?

[ T: ]

Tuesday Feb 07, 2006

Outstanding Questions for Sun, Intel, AMD and others...

Well I don't speak for AMD, Intel or Sun for that matter but I have some comments regarding the questions here.

I'm sure it possible to make a lower electrical power Ultrasparc with less cores or slower clock or make a higher compute power version with even more cores  or faster clock, If you wanted to model or make one yourself the chip design tools and specs to do it are here.

While The  UltraSparc T1 has 8 cores and 4 threads per core giving 32 hardware threads  and no other commercially available chip comes close to it. It is more important to think of the whole system it will used in like I blogged before here, So once you see the final product you can see the reasons why the other choices were made.

If your interested in the AMD space we've used the same design criteria, and as Marc Andreessen discussed here (the numbers are here) its the most cost efficient solution.

[ T: ]

Wednesday Jan 25, 2006

OpenSolaris Appliances

Well the OpenSolaris Appliances community is beginning to take shape. Now the fun part is deciding what it is :) A few wish lists are starting to appear in blogs and on the discussion pages. We have ideas around Qube or Media PC replacement. To Me the media PC is not that interesting without first creating the “Qube” with 2005 technology.

My requirements for OpenSolaris Appliances 1.0

  • NAS server SMB and NFS

  • High performance and low cost

My requirements for OpenSolaris Appliances 2.0

  • NAS server SMB, CIFS, NFS

  • DHCP Server

  • Firewall

  • Name Server DNS and LDAP

  • Print Server

Nice to have in OpenSolaris Appliances 2.0

  • Web Server

  • Mail server

  • Simple & easy management

  • Easy interoperability with other home network devices

So for Me the problem I want to solve first is sharing and securing of several hundred GB of data, this is the key area where I think OpenSolaris can outperform all other appliances. Once We have that done then all the other features should just be software upgrades.

[ T: ]

Tuesday Jan 10, 2006

Sun/Oracle Town Hall - "What does this mean for DBAs?"

I've just been googling news about Oracle and Sun after today's Sun/Oracle Town Hall meeting at Oracle Headquarters, a mini Oracle World keynote was my first impression - lights/music - If you've been to an Oracle World keynote you know what I mean. Then  Scott and Larry on stage for an hour, 10 minutes of jokes mostly around acquisitions, a 40 minute presentation, 10 minutes of questions.

Its interesting to see how a one hour event gets compressed into a paragraph or two by different news organizations and the points that they decide to focus on. If you read 5 or 6 articles you'll get a good overview of what when on.

Most of the news articles picked up on the Oracle preferred Sun, then Oracle preferred Linux, now Oracle prefers Sun again theme. You could just as easily interpret history as Oracle has always preferred Sun except for the time when the only easy way to use cheap x86/x64 machines was with Linux, when given the choice between cheap x64 boxes running Solaris or Linux Oracle choose Solaris.

There was one phone question   "So what does this mean for DBAs?" which didn't get the follow up deserved

We could follow this train of thought - going forward you will be able to purchase a Sun server with Oracle pre-installed. This gives us an opportunity to do some configuration of the server while at the factory so you don't have to. There are some easy setup decisions since we know you are going to be running oracle you will need a dba group and an oracle user. We don't have to modify /etc/system since in Solaris 10 we can configure shared memory, semaphores on the fly in /etc/project we could put oracle in the FX scheduling class, use the fair share scheduler, configure a zone(s) for oracle etc, all of these things will improve performance or ease of use, we can do more but where do we stop?

I suppose what I really want to know is what setup would most System Administrations and DBAs agree on so we can make them the default. Less  customization means less configuration issues.

[ T: ]

Monday Jan 02, 2006

High CPU usage on Oracle RAC investigation with statspack - followup

I just saw this here
- Many DBAs feel that if the data is already contained within the buffer cache the query should be efficient. This could not be further from the truth. Retrieving more data than needed, even from the buffer cache, requires CPU cycles and interprocess IO. Generally speaking, the cost of physical IO is not 10,000 times more expensive. It actually is in the neighborhood of 67 times and actually almost zero if the data is stored in the UNIX buffer cache.

One must always be careful when using the UNIX buffer cache with Oracle
The default Unix behavior is to comply with the POSIX standard for reading and writing files

Read-Write Locks and Attributes

Read-write locks (also known as readers-writer locks) allow a thread to exclusively lock some shared data while updating that data, or allow any number of threads to have simultaneous read-only access to the data.

So the default file system behavior is not optimal for oracle, since oracle can manage its' file accesses e.g. not reading a block while that same block is being written. The extra layer of protection that POSIX gives is not needed. You can improve your IO concurrency in Solaris by adding the directio mount option to the database partitions in /etc/vfstab, or you could set the Oracle Parameter FILESYTEMIO_OPTIONS to SETALL

You may now want to increase the size of the buffer cache since oracle is now bypassing the buffer cache and some of that memory can now allocated directly for oracle buffers.

[ T: ]

Tuesday Dec 20, 2005

Oracle license for UltraSparc T1 the same as Dual Xeon

It's finally official you can read about it here, page 8 has Oracle's description of a processor for licensing calculations. So to summarize Oracle Enterprise license is $40000 or ($60000 with RAC) per processor.

When a chip has multiple cores the rules change
  • UltraSparc T1 core factor .25
  • AMD or Intel core factor .5
  • Everthing else core factor .75
So an 8 core UltraSparc T1  8 \* .25  = 2 oracle licenses = $80000
A dual Xeon server 2 \* 1 = 2 oracle licenses = $80000

[ T: ]

Monday Dec 19, 2005


NOP for technorati <script type="text/javascript" src=""></script>

Friday Dec 16, 2005

Dr Dobb's Thoughts on Language Design

I just got a Dr Dobbs Update email, The first article that caught my eye was Thoughts on Language Design by Guy Steele. In a nutshell a programming language dictate how we think about problems and how we solve them. Most programming today is built around the single thread of control with binary choices if-then-else etc.  The article raises some good ideas around rethinking this programming model.

My vote for a completely different model would be this.

Thursday Dec 15, 2005

Ruby on Rails and OpenSolaris

I've been meaning to look at Ruby / Ruby on Rails for some time now, well ever since I heard there was a DTrace provider for it. After seeing that RoR version 1.0 had been released that made now a good time to take a look.

What is RoR 1.0
  • Ruby 1.8.2 an interpreted language - a 3.6M tarball  compile yourself
  • RubyGems 0.8.11 - ruby package manager (written in Ruby) - 160K tarball
  • Rails - web application development framework  (written in Ruby picked up from and installed on your machine)
The default behavior of ruby and gem is to install the binaries, libs and man pages in /usr/local so you will need to have write permission there.

I followed the install instructions it all went very smoothly all the gnu tools required ship with Solaris 10 and OpenSolaris in /usr/sfw/bin (make sure it's in your PATH)

Now it's time to see what RoR can do!

[ T: ]



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