Kilala.nl - Personal website of Thomas Sluyter

Unimportant background
Login
  RSS feed

About me

Blog archives

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

> Weblog

> Sysadmin articles

> Maths teaching

<< 7 / 2013 9 / 2013 >>

Start of the new kendo season

2013-08-28 06:12:00

Last week saw the start of the 2013/14 kendo season at Renshinjuku dojo. I'm very happy that Heeren-sensei is joining us again after his prolonged absence. On the other hand, I still haven't seen any of the other teachers including Tsuyuguchi-sensei. As per yesterday we moved to our new training hall at Jane Addamslaan, now that the Westend hall is getting decomissioned. 

The first two classes of the season were spent on rebuilding our physical condition after a few weeks of slacking off* and on improving tenouchi (手の内, lit. "the inside of your hand"). Tenouchi is the term used to describe a specific kind of grip or movement, made using your hands and wrists at the moment when a strike connects. Geoff Salmon-sensei has written a lot about it

Heeren-sensei reminded us of the importance of training at home. Once or twice a week in the dojo isn't enough if you want to make real progress! Doing suburi will keep you agile and will help with tenouchi. And making a striking dummy will even let you do basic kihon practice! You can even do suburi inside, but making a suburito from old shinai parts.

After the usual warmup routing, we proceeded to bogu-less exercises. Motodachi receives and counts men strikes on his shinai, which is held in front of his face. Each person needs to do fifty strikes, totaled up to 150 by rotating three times. Last week we also included two times fifty hayai suburi. Heeren-sensei asked us to do these exercises with three things in mind:

  1. The upswing reaches all the way back, tapping your rear.
  2. The upswing has your left hand passing right over your head, almost combing through your hair.
  3. The strike should be made strongly, focusing on the left hand.

These three factors combined help you train tenouchi.

For similar reason we then proceed to interval training, with each couple doing kirikaeshi all 'round the perimeter of the dojo floor. Each person needs to make a minimum of four rounds. Heeren-sensei pointed out the following:

Class is finished with 10-15 minutes of free jigeiko and kirikaeshi.

*: In my case that's three months due to my knee injury. After visiting my GP I stopped kendo a month early. Despite the doctor's expectations it took more than two weeks to get rid of all the pains. More like six to eight. After that the pain was gone, but reappeared after last week's class. I've now bought a knee brace, which appears to be helping a lot. I still need to have a checkup by a physio-therapist.


kilala.nl tags: , ,

View or add comments (curr. 0)

Installing CentOS Linux as default OS on a Macbook

2013-08-12 16:46:00

While preparing for my RHCSA exams, I was in dire need of a Linux playground. At first I could make do with virtual machines running inside Parallels Workstation on my Macbook. But in order to use Michael Jang's practice exams I really needed to run Linux as the main OS (the tests require KVM virtualization). I tried and I tried and I tried but CentOS refused to boot, mostly ending up on the grey Tux / penguin screen of rEFIt

On my final attempt I managed to get it running. I started off with this set of instructions, which got me most of the way. After resyncing the partition table using rEFIt's menu, using the rEFIt boot menu would still send me to the grey penguin screen. But then I found this page! It turns out that rEFIt is only needed in order to tell EFI about the Linux boot partition! Booting is then done using the normal Apple boot loader!

Just hold down the ALT button after powerin up and then choose the disk labeled "Windows". And presto! It works, CentOS boots up just fine. You can simply set it to the default boot disk, provided that you left OS X on there as well (by using the Boot Disk Selector).


kilala.nl tags: , , , ,

View or add comments (curr. 0)

RHCSA achieved

2013-08-12 16:23:00

Huzzah! As I'd hoped, I passed my RHCSA examination this morning. Not only is this a sign that I'm learning good things about Linux, but it also puts me 100% in the green for my continued CISSP-hood: 101 points in domain A and 62 in domain B: 163/120 required points.

I can't be very specific about the examination due to the NDAs, but I can tell a little bit about my personal experience. 

The testing center in Utrecht was pleasant. It's close to the highway and easily accessible because it's not in the middle of town. The amenities are modern and customer-friendly. The testing room itself is decent and the kiosk setup is exactly as shown in Red Hat videos. Personally, I am very happy that RH started with the kiosk exams because of the flexibility it offers. With this new method, you can sit for RHCSA/RHCE/etc almost every day, instead of being bound to a specifc date. 

The kiosk exam comes with continuous, online proctoring meaning that you're not stuck of something goes wrong. In a normal exam situation you'd be able to flag down a proctor and in this case you can simply type in the chatbox to get help. And I did need it on two occasions because something was broken on the RH-side. The online support crew was very helpful and quick to react! They helped me out wonderfully!

I prepared for the test by using two of Michael Jang's books: the RHCSA/RHCE study guide and the RHCSA/RHCE practice exams. If you decide to get those books, I suggest you do NOT go for the e-books because the physical books include DVDs with practice materials. Without going into details of the exams, I found that Jang's books provided me ample preparation for the test. However, it certainly helps to do further investigation on your own, for those subjects that you're not yet familiar with. 


kilala.nl tags: , ,

View or add comments (curr. 0)

Security measures all of us can take - part 3

2013-08-10 22:53:00

Here's another follow-up with regards to security matters I believe everybody should know. It's a short one: Email is not safe.

It has been said that you "don't put anything in an email that you wouldn't want to see on the evening news." It's not even a matter of the NSA/FBI/KGB/superspies. Email really is akin to writing something on a postcard: it's legible to anyone who can get his hands on it. And like with the postal service, many people can get their hands on your email. 

Here is an excelent and long read on the many issues with email. But to sum it up:

  1. In general, emails are transfered and stored unencrypted. Anyone on the same network as you can read them in passing. Anyone managing an email server can read the mails stored on them.
  2. Source/sender information is easily spoofed. There is no way to guarantee that an email actually came from whoever's name is at the top. 

These two problems can be worked around in a few rather technical manners, most of which are not very user friendly. The most important one is to use GPG/PGP, which allows you to encrypt (problem 1) and to digitally sign (problem 2) the emails that you send. It certainly helps, but it introduces a new problem: key exchange. You now need to swap encryption keys with all people with whom you'll want to swap emails. But at least it's something. 

In the mean time:

Want to send me an encrypted email? Here's my public key :)


kilala.nl tags: , ,

View or add comments (curr. 0)

An update on certifications

2013-08-07 22:09:00

Here's a follow-up post to last year's "Confessions of a CISSP slacker".

By the end of last year I was woefully behind on my CPE (continued professional education) requirements, which are needed to retain my CISSP certification. Not only is CISSP a darn hard exam to take, but ISC2 also need you to garner a minimum of 120 study points each three years. In my first two years, I didn't put in much effort meaning I had a trickle of 51 points out of 120. Thus my emergency plan for making it to 120+ points in the span of a year.

All the calculations were made in the linked article and then I set things into motion. My resolve being strengthened by my personal coach I put together a planning for 2013 that would ensure my success. And my hard work has been paying off, because as of tonight I have now achieved the first milestone: the minimum of 80 points in "domain A" (screenshot above). 

The heaviest hitters in obtaining these 29 points are:

The remaining points were garnered by attending online seminars and by perusing a number of issues of InfoSecurity Professional magazine

Next monday I'm scheduled to be taking my RHCSA (Red Hat Certified System Administrator) exam. I've been working hard the past three months and I'm confident that I'll pass the practical exam on my first go. If I do, that's a HUGE load of CPE because all the study time counts towards my CISSP. That would be roughly 20 hours in domain A (security-related) and 60 hours in domain B (generic professional education). And that, my friend, would put me squarely over my minimal requirements! And I haven't even finished all the items on my wishlist :)


kilala.nl tags: , ,

View or add comments (curr. 0)

<< 7 / 2013 9 / 2013 >>