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Most recent entry: 2014-07-08 00:00:00 -- Generated on 2014-07-22 16:57:48 by Rig3 0.4-440




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2014/07/08 Simraceway/Sears Point Formula 3 - Stage 2
π 2014-07-08 00:00 in Cars
After doing stage 1 some months back, I went back to learn stage 2. I definitely got better with downshifting the 2nd day once I figured out that my foot was too wide and I was pushing brake and gas a the same time, preventing downshifts from happening. This was fixed by turning the brake pedal two turns towards me.





Here are some of notes of what I learned those 2 days:

  • faster upshift (barely get off throttle)
  • faster and harder transition from gas to brakes (same end pressure, faster transition)
  • Do not brake and gas, this prevent shifting
  • passing: When you are side to side but not quite for a turn, you must release the brake to win the corner since you cannot stop any more. If someone is trying to pass on the outside, you brake even more to leave them room to be side by side with you. The inside guy gets the apex no matter what, even if not wheel to wheel


  • And notes relative to actual turns:

  • carry speed into 2, do not brake so much and gas back up, just keep speed going up
  • lift before turning 3a, start turn and put a bit of gas more gradually (do not remove gas)
  • 4 brake early enough not to understeer
  • 5 flat out
  • 6 good brake on top but not so hard, light brake, coast, and early gas half way down
  • 7 brake 3rd cone, good brake pressure
  • 8 go faster and turn later so that I can connect 8a
  • 9a get on the brakes faster, be a bit faster turning the wheel from 9a to 9b, scandinavian flick
  • 10 flat out, shift before turn in 10 so that I'm not as sluggish in the turn
  • The 2nd day in the morning, I got a flat on one of my tires without knowing, which made the car very oversteery and before I knew it, I spun in the ss'es and got to see why:


    This time we were running the full course and had slicks on the cars, so it was a good difference from level 1.
    We only had 4 people in our group, and one was close to a professional racer, so I didn't get too close to him. As a result our end times on the 2nd day were the following: our teacher Nico had a benchmark time of 1:38, our next best driver was at 1:41, I got down to 1:43, and the 2 other students with less experience were around 1:48.

    After driving, we compared our data acquisition to see what we were doing wrong or could improve:


    My last 2 sessions the 2nd day in the afternoon, my times were reasonably stable and in the down direction :)

    One before last session: 1:48, 1:48, 1:47, 1:48, 1:45, 1:48, 1:46, 1:46, 1:46, 1:46, 1:47, 1:46, 1:48

    Last session (with video offset): 1:45 ( 0:37), 1:45 ( 2:22), 1:46 ( 4:08), 1:45 ( 5:53), 1:45 ( 7:38), 1:44 ( 9:22), 1:48 (11:06), 1:44 (12:50), 1:44 (14:34), 1:44 (16:18), 1:44 (18:01), 1:43 (19:44), 1:44 (21:28), 1:44 (23:12),

    Here is a vid of my last session

    And for novelty purposes, a shaky video from google glass of an ealier session:

    2014/06/26 5 Miles of Thunderhill in an Elise with Golden Gate Lotus Club
    π 2014-06-26 00:00 in Cars
    Since my track car won't be available for another couple of months, when I heard that GGLC was going to get one of the first 5 mile track days at Thunderhill, I figured I'd look into renting and was told about Dietsch Werks.

    As a result, I ended up renting a track prepared lotus from them (lightened, a few extra HPs over stock, and upgraded brakes). I did however select street tires over slicks since I figured I didn't need to learn slicks when I was already learning a new car and a new track.

    I ended up flying early that morning just around IFR weather and got to Willows airport where Rob picked me up.



    By 09:00, we started our first session, one of 7 30mn sessions :)



    there were other bug cars :)
    there were other bug cars :)

    It took me a little bit to get used to the lotus and learn that it was tail happy under braking. As a result, I had to brake and be back on gas before turning for stability in some places.
    Learning thunderhill west also took a bit of time, but I worked my way down from 4:10 to 3:44 by the end of the day, so I'm happy enough with that :)

    Here is my last session of the day (just to 20:22):

    Thanks to GGLC for setting up the event and Rob and Jenni for getting me the car all prepped.

    100_20140626_Thunderhill_5mile_Elise_GGLC 101_20140626_Thunderhill_5mile_Elise_GGLC 102_20140626_Thunderhill_5mile_Elise_GGLC 103_20140626_Thunderhill_5mile_Elise_GGLC 104_20140626_Thunderhill_5mile_Elise_GGLC 105_20140626_Thunderhill_5mile_Elise_GGLC
    2014/06/23 Another Visit of Midway Aircraft Carrier in San Diego
    π 2014-06-23 00:00 in Flying
    I had spent over 3 hours in 2012 and didn't get to finish the top last time, so I went back with Arturo and we spent another 3-4H to do the top. Clearly doing the whole thing carefully takes a whole day from open to close.

    This time though we started with the top deck which usually is a 1H line and we saw right away, and then we worked through the flight deck:



    Captain's view
    Captain's view







    From there we saw the captain's quarters and surroundings, ops and comm rooms:








    From there, we went to the flight deck and dispatch rooms:









    landing signals
    landing signals














    There was a lot more to see in the aircraft carrier, but we had done a good amount for the day (and this mostly completed my prior visit where I had seen all the bottom floors in details).

    2014/06/21 Diving San Diego: Kelp, Ruby and Yukon wrecks
    π 2014-06-21 00:00 in Diving
    Arturo, Regis, and Bill invited me to their diving trip in San Diego, and having forgotten how cold it was last time, I foolishly accepted :)

    I brought a semi dry 7mm wetsuit, a full hood, and as a backup a 2nd shortie with hood that was 5.5mm (or a total of 12.5mm of neoprene). That was a wise decision, the semi-dry 7mm wasn't much warmer than a 7mm, and after my first dive, I was very cold, so I put the 2nd wetsuit on top.
    This turned out to be barely enough, and I was still cold on most of the dives, but it turns out the temperature got as low as 13C (55F). It was sad when I saw my computer say 16C (60F) and that felt warm, but the 2 wet suits, tight hood, and 28lbs of lead just weren't comfortable or fun.

    All that said, we had above average vis (which means somewhat poor instead of very poor ;) ), and no current, so we got lucky with the conditions actually being as good as they could have been for there (except the temps).

    On the first day, we did a couple of kelp dives first, and the Yukon and Ruby in the afternoon. On the second morning, double dive of the Yukon on nitrox, and finished up with the Ruby again, where I took a crap on the toilet :)

    Unfortunately most of my pictures are crap because my real camera lens kept fogging up. I used my gopro as a backup, and the nicer pictures are from Arturo.





    there we so many lobsters, it wasn't even funny:








    Some pictures from the wrecks:






    2014/05/21 My Btrfs Talk at Linuxcon JP 2014
    π 2014-05-21 00:00 in Btrfs, Linux
    This all started with my trying Btrfs after Avi Miller's talk at Linux.conf.au. I started asking some questions on the mailing list, and since the wiki wasn't up to date on them, I ddi the obvious thing to start updating the Main Btrfs Wiki here and there.

    After I had learned a fair amount about Btrfs already I felt others would benefit from a introduction to it, as well as best practises and what features it offers that would make you want to switch, I ended up submitting a talk to Linuxcon. In the process of writing the talk, I learned even more about Btrfs, and wrote some of them on my Btrfs blog while linking or putting the other relevant ones on the Main Btrfs Wiki.



    The fancy talk description is here:

    The presentation will give you everything you know to get up to speed with btfrs, why you should want to trust your data to btrfs, how it offers a lot of what ZFS offers without the licensing problems, as well as best practices for using it.

    I will go into:

  • the basics of administration of a btrfs filesystem
  • How btrfs, swraid, dmcrypt, and lvm fit or don't fit together
  • how to work with a single storage pool and create all your partitions from it without having to ever resize them, or require LVM as a slow and somewhat unreliable block layer.
  • how to have virtually as many snapshots as you want and why you really want this
  • how to do very efficient block level backups of changes only and much faster than rsync ever will
  • how those block backups can be used to deploy OS upgrades at the file level like I explained in my talk on how Google maintains its many servers last year.
  • The video:

    The quality isn't great due to poor lighting, sorry about this, but you get the talk slides here or view them inline below.
    For easier to click on links, you may prefer the pdf version or the libreoffice version.


    > To click on URLs in the presentation, click on 'with contents' in the upper left, and use those links (open to a new tab)

    See more images for My Btrfs Talk at Linuxcon JP 2014
    2014/05/20 Historical Snapshots With Btrfs
    π 2014-05-20 00:00 in Btrfs, Linux

    How to manage historical snapshots of backups with Btrfs

    I have a setup where I backup a certain number of machines to a central server. There are multiple ways to do hierarchical backups with btrfs.

    snapshots and rsync on top

    http://marc.merlins.org/linux/talks/Btrfs-LC2014-JP/html/img33.html
  • not great because of COW relationship lost to unix tools,
  • not great because backing up server on another one requires a lot more snapshots of snapshots for btrfs send of old things that never change
  • works for deduping data that partially changes or changes owners
  • cp -a --link + rsync

    http://marc.merlins.org/linux/talks/Btrfs-LC2014-JP/html/img34.html
  • newer btrfs should be ok with many hardlinks
  • du can figure out the data saved
  • you can use hardlinks.py instead of bedup
  • can be transferred via cp/rsync without losing links
  • but hardlinks will not work across subvolumes
  • cp -a --reflink + rsync

    http://marc.merlins.org/linux/talks/Btrfs-LC2014-JP/html/img35.html
  • very nice, does not require hardlinks which you can't do across subvolumes
  • works for deduping data that partially changes or changes owners
  • but totally lost as soon as you copy it anywhere else (unless you use btrfs send)
  • 2014/05/20 Linuxcon Japan 2014 in Tokyo
    π 2014-05-20 00:00 in Linux
    I was thankful to be invited to Linuxcon Japan to speak again this year, and I did a talk about the usage for btrfs.


    A few pictures from the event:

    Keynotes:





    A few talk slides:




    A very interesting talk for Japanese people on how they can better interact with the linux community and what pitfalls they should avoid:




    And gatherings/people:



    it had been ages since I had last seen Daniel Veillard from RH, a containerization expert. Made for good talks.
    it had been ages since I had last seen Daniel Veillard from RH, a containerization expert. Made for good talks.



    my buddy Horms
    my buddy Horms

    the French connection :)
    the French connection :)


    See more images for Linuxcon Japan 2014 in Tokyo

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