Today on this ol' server

Remember Ada Lovelace

"[W]e may say most aptly that the analytical engine weaves algebraical patterns just as the Jacquard loom weaves flowers and leaves." Ada Lovelace around the 1840s. It was a woman that took the concept of the analytical engine the precursor to the modern computer and refined the concept of programming the analytical engine. The blogosphere celebrates Ada Lovelace day by remembering her and looks forward to cheer women already in technical disciplines and welcome newcomers to all technical disciplines. Yes we, you and I can. We can compute, abstract, record, test and examine. With those basic elements anyone can participate in Science and Technology.

Posted at 11:36PM Mar 24, 2009 by saf in Sun  |  Comments[0]

Is that a hybrid in your pocket?

In the reduce your carbon footprint front, I've gone without a car for about 9 months now. I bid my beloved nineteen seventy-two 2002 BMW farewell last year in some drastic it's-not-my-fault bad luck.
When the time came to replace my car or go without, I decided to take the plunge and not buy another car. In the Bay Area this is possible. Work is supportive, they have shuttles between campuses and near by train stations and telecommute options. [Read More]

Posted at 12:00AM Mar 13, 2009 by saf in eco  |  Comments[2]

No need to sync a mirrored swap volume

Today's quick tip, is how to get SVM to not sync a mirrored swap volume.

Per best practices on hosts running Solaris versions incapable of root mirroring with zfs, use Solaris Volume Manager. For those of you out there that are still running legacy versions of Solaris or older versions of S10 you can set up SVM to not sync a mirrored swap volume with metaparam(1m).

root@thumper # metaparam -p 0 d20
root@thumper # metastat -p | grep d20 
d20 -m d21 d22 0

At boot time before I made the change there was about 30 seconds spent waiting for the disks to sync. And right now after the change there aren't any writes being written to d2*

thumper% iostat -xnz 2
                    extended device statistics              
    r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device
    0.3    0.5    1.0    1.1  0.0  0.0    0.1    1.9   0   0 md/d10
    0.1    0.5    0.5    1.1  0.0  0.0    0.0    1.5   0   0 md/d11
    0.1    0.5    0.5    1.1  0.0  0.0    0.0    1.3   0   0 md/d12
    0.0    0.0    0.1    0.1  0.0  0.0    0.0   30.5   0   0 md/d20
    0.0    0.0    0.1    0.1  0.0  0.0    0.0   33.6   0   0 md/d21
    0.0    0.0    0.1    0.1  0.0  0.0    0.0   24.7   0   0 md/d22

Posted at 04:34PM Jan 07, 2009 by saf in Sun  |  Comments[0]

Importing zfs pools

How to import disks recovered after a reinstall or upgrade. Run zpool import -d against the directory that holds your disk devices.

root@thumper #  zpool import -d /dev/dsk/
  pool: compilers
    id: 12162905211102209752
 state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:

        compilers    ONLINE
          raidz1     ONLINE
            /c0t0d0  ONLINE
            /c1t0d0  ONLINE
            /c4t0d0  ONLINE
            /c6t0d0  ONLINE
            /c7t0d0  ONLINE

Each zpool device will have a unique id. Run zpool import -d $DEVICE_DIRECTORY -f $ID where ID is either the name or the numeric id. I used the numeric id when I did the import. First try without the -f option. If the disks were exported then you won't need the -f. If you're recovering from a system crash or hardware failure it's likely the pool was not exported prior to the crash. -f forces zfs to import the pool even if it thinks it's active.

root@thumper # zpool import -d /dev/dsk -f 12162905211102209752 

If the import was successful zfs won't return any state message. Check that the pool was imported correctly by zpool status.

root@thumper # zpool status
  pool: compilers
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        compilers   ONLINE       0     0     0
          raidz1    ONLINE       0     0     0
            c0t0d0  ONLINE       0     0     0
            c1t0d0  ONLINE       0     0     0
            c4t0d0  ONLINE       0     0     0
            c6t0d0  ONLINE       0     0     0
            c7t0d0  ONLINE       0     0     0

Posted at 07:14PM Dec 04, 2008 by saf in Sun  |  Comments[0]

BayLISA usergroup to feature DTrace talk

Happening tonight, Jonathan Adams is going to speak on DTrace at the regular BayLISA usergroup meeting. If your around Sunnyvale, come and stop by.

If you're brining your laptop, download OpenSolaris then VirtualBox and try out DTrace or follow along with the presentation.

To learn more about DTrace visit these links:

Getting Started

DTrace Wiki

DTrace How To guide

Resources

DTrace Bigadmin Hub

DTrace community at opensolaris.org

Use DTrace

DTrace toolkit

Solaris Internals DTrace Repository

Presentations

Javaone Technical Sessions 07

Techdays DTraceToolkit Presentation

Posted at 06:03PM Jul 17, 2008 by saf in events  |  Comments[0]

mechanicrawl

The long now foundation is having a mechanicrawl in San Francisco tomorrow afternoon lasting till 8pm.

Posted at 06:00PM Jul 11, 2008 by saf in events  |  Comments[0]

Please sir, could I have more Solaris?

With the latest release of opensolaris you now get a snazzy LiveCD image that conveniently fits on a cdrom, dvd or usb drive. With that you can then try out all those Solaris only features like the new package manager, Service Management Framework, Fault Management, DTrace, zfs, zones and containers and the Solaris older kernel profiling tools without wipeing out your existing OS. So go ahead, get some more Solaris and while you're at it, benchtest some DTrace with this hands on lab.

Posted at 12:11AM Jun 11, 2008 by saf in Sun  |  Comments[1]

Ask a Scientist monthly lecture

Ask a Scientist is having it's monthly event tomorrow in the city, by Craig Reynolds on Boids and other computer simulated swarming and flocking behavior.
It's at the Axis Cafe, 1201 8th Street (btw. 16th & Irwin), San Francisco, CA

Posted at 06:08PM Jun 10, 2008 by saf in events  |  Comments[0]

Station X

I was surprised at how heavy the keys were. I was at Station X in Brittan, or better know as Bletchley park. It was 2001 and I was hitting the keys on an old WWII German enigma machine. Think of the keys on an old ibm selectra, but heavier. The plug board lit up when I hit a key. There was a buzzing sound as the light was lit. Next I tumbled the rotors. Latch, catch, tick, tick . . .

One of the rare finds in computing history lore and legend is Bletchley Park. This is where Alan Turing worked after writing "On computable numbers, with an application to the Entscheidungsproblem" which introduced the Turing machine. During WWII all communications required deciphering were processed at Bletchley Park. They needed speed, lives were at stake. They needed accuracy. The perfect job for a machine, only there wasn't one. Yet.
The very man who had conceived entirely original rigorous way to determine if it was possible that any type of logical statement (that can be broken up in to mathematical grammar) would complete, needed an automated way to decrypt non-trival codes. He worked on a team to devise ways to automate the cracking. After building the Bombe the team realized a need for the machine to be able to be reprogrammed, akin to how a modern computer operating system can run more than one program. The Colossus is considered one of the worlds first programmable computers. Similar to a modern computer program the Colossus was a reprogrammable machine that would do use algorithms to decipher the messages.

The Park recently finished building a replica of the Colossus. Last year the Park had a contest to see if a developer could beat the newly rebuild Colossus. (All the machines and plans were destroyed shortly after WWII ended. Except that our NSA kept a copy of one of the plans for the Bombe and Colossus. That story is a great vignette in and of itself.)

Now we have computers in phones, cars, vacuum cleaners, in addition to the tradition servers living in datacenters. We even have self-healing features where software will recover from a set of defined hardware and software errors.

On a more somber note, last Saturday marked the 54th anniversary of Turing's death. I think if Turing were a live to day I'd like to think he'd be proud at how far we come. I'd like to think that if he visited our time he'd see amazing cities, vibrant communities, as well as places and attitudes that have far transcended his 50s Brittan. I'd hope he'd be pleased with our efforts to continually push the envelope. I'd hope we'd understand that we need to move past just tolerating people that are different to acceptance. The world lost a great mind for the pettiness of not be able to accept one different from ourselves over some superficial trait.

Posted at 12:41AM Jun 09, 2008 by saf in musing  |  Comments[0]