Thursday, June 16, 2016

How to make you passengers angry- Thank you spicejet

I was booked on spice jet flight SG613 from BOM to MAA with a scheduled departure time of 2215. The inbound flight was SG 418 from BLR that took-off 40 minutes behind schedule at BLR.

I arrive at the check-in counter at 2100 and after waiting for about 15 minutes, I get my boarding pass. The time was around 2120, the inbound flight was 40 minutes into it 1h40minute filght, spice jet by now knows that the fight is delayed at least 40 minutes late, They could have informed the passengers that the fight is late pro-actively, It was my fault to assume that they would tell the passengers of the day, I should have asked.

Once I have my boarding pass, I pass security very swiftly and arrive at the gate.

The FIDS shows that the flight is on time even though spice jet knows that the fight is delayed at BLR.[1]

The inbound aircraft arrives at around 2210 and is deplaned.

I don't remember when boarding started so I will not speculate on the time.

I board the 737-800 only to find the air conditioner not being switched on inside the plane. The air-hostesses provide water to the passengers which was a welcome move considering that I was sweating profusely on the plane. The plane felt like a MTC bus less like a state of the art aircraft.Boarding get done around 2257.

The cabin lights are dimmed and we push-back to taxi to the runway. A lot of passengers are unhappy that the A/C was not powered up. I felt bad for the air-hostesses working on the plane. It was finally switched on just before or after take off.

The plane finally takes off at 2317 [2] which is a full hour behind the scheduled time and the cabin cools down.

I dosed off some time just after the plane took off. just to be woken up in a few minutes with the lights fully switched on for dinner service. Dinner at 2330, that very very late for dinner and very aggravating for the passengers that are sleeping.

I don't remember much of what happened in till the flight lands.

The flight finally landed at 0052 [3]. I have never been more relieved to find myself entering MAA.

So what did I learn from this?
I'm never flying spicejet again.
I might be a small fish for spice jet in the giant ocean but I'm never flying spice jet ever again.



Monday, June 6, 2016

A laymans guide to buying a thinkpad

Thinkpads are great laptops. originally sold by IBM, now they are sold by lenevo

Why should you buy a Thinkpad over other laptops?

  1. They are built like tanks
  2. function over form
  3. Cheap (when you buy used)
  4. Spilling water on the keyboard does not ruin the laptop
  5. The service manuals are available online
  6. The can be used with docking stations
  7. Trackpoint - much much better than a trackpad
  8. Great linux support

There are several Thinkpad ranges

W series - work station's( desktop replacements, think big bulky monstrosities )

T series - Everyday business laptops

X series - ultra-portables before ultrabooks became popular

P series - replaces the W series

And several others branded thinkpad, The other ranges in my opinion are thinkpads in name only, They are not built to the same quality as the above ranges.

Naming of Thinkpads

A modern  Thinkpad name is four characters long, a letter that denotes the model and three digits following it



W- series

5 - size ( 2=12" , 3=13" ,4=14", 5=15" )

3 - Generation of laptop and it corresponds to which generation intel core i processor is in it ( 0= 1st gen, 2 = 2nd gen , 3= 3rd gen and so on)

0 - just a place holder

What Thinkpad to buy?

1.Just need a Thinkpad for browsing/face-booking/media consumption

  • The T series- Great over all laptops, choose between 14" and 15"
  • My favorites- TX20 and TX30 
2. Something small and powerful

  • The X series
  • X220 X230, X250 and X260
3. You want a laptop that can be used as a room heater

  • W530 with the i7
  • P50 , P70
one small warning , there are Thinkpads with an s or an i suffix to the name
eg - t420s or a x220i - they are equipped with slower processes so I would avoid them.

What to look for when buying a Used Thinkpad

1. Look at the physical condition for the machine, A little wear is acceptable any thing more than that points to abuse.

2. Make sure that there is not BIOS supervisior password. A bios password points to a laptop that might have been stolen

3. Make sure that there are not dead pixels on the screen.

4. Test the hinde, Open the screen and move it to about five centimeters above the keyboard. The screen should hold it self up, lack of this might point to a loose hinge

5. Make sure that you are getting the original power adapter with the laptop.

Friday, April 4, 2014

Lessons learnt after setting up Wifi for Abacus Hackathon

Abacus is a Computer Science symposium conducted by the students of CEG.

The Hacakathon for this year was sponsored by Freshdesk and was called Save The Hacker

Here are some of the lessons that I learnt

Lesson 1:
Have an access point per 10 attendees

Turns out that people at a Hackathon have more that two devices that connect to the wifi network per person.

We had three access points for ~60 people while the wifi worked fine for most of the time, it fell to pieces when people started to torrent(will get to that later)

Lesson 2
Have both channels with access points that have band steering

I used ubiquiti nano stations as my access points,these are single channel 2.4 GHz radios, while the three access points were in different channels, there are only three non overlapping 2.4Ghz channels.

I wish, I had dual channel radios in my access points that would allow me to steer the clients to the less congested 5Ghz band where there are over ten non over lapping channels to use

Lesson 3
Have a local transparent proxy and a local DNS cache
I think that the INTERNET would have felt faster if there was a local transparent proxy on the network

The Internet also felt slow as the DNS server that was on the university network was taking in the order of 2000ms for a DNS request, this caused the network to seem super slow, even though the available bandwidth was over 100 megabits per second 

Lesson 4
Have monitoring  on the network(relegated to no 5)
The ubituiti gear is not supported my NAGIOS properly, I made a mistake by not having any kind of monitoring on the network except for inbound/outbound bandwidth. This ended up being a huge mistake because the network becaume very slow at one point through the hackathon and I could not figure out what was wrong .

Lesson 5
Throttle/ enforce qos on P2P downloads like torrents
All the ports were open on the network, this caused the participants to start downloading torrents over the network. This causes the network to slow down to a complete crawl and at one point causing wifi clients to deauth( could also be due to no 6)

Lesson 6
Discourage use of personal hotspots like connectifi
A lot of the participants were using personal hotspots that were causing the spectrum to be fully utilized, this can also be mitigated by moving to 5 GHz radios on the access points

Lesson 7
Have RF monitoring tools
I recommend any one attempting to have a large wifi network to have a rf monitoring tool, that allows you see spectrum utilization and take action based on that

I will put up another blog post on all the gear used for the hackathon

Wednesday, March 20, 2013

Linux is amazing

I got up this morning and woke up laptop from sleep, everything appeared normal, all my browser windows and the respective tabs opened up and I started browsing from where I left off last night.

About three hours after I woke my computer I tried to launch KeepassX my password manager, Thats when I noticed something odd happening, It wouldn't launch. I switched to a terminal I had running and tried to find out what was happening. I couldn't use any binaries. I was confused on what was happening. Thats when ubnutu told that my computer was operating outside normal parameters which was caused due to something being wrong with my hard drive. Thats when I figured out that my hard drive was dead.

This meant that linux was completely ruining from memory, I sit here writing this blog from a machine with a dead hard drive running everything in memory from the last time it was loaded.

I'm amazed the OS did not just crash.

I'm impressed linux, good job :D

Sunday, September 16, 2012

Will we see OSX running on the IPAD?

I think that it is possible to imagine that apple will release a version of osx for the iPad and call the resulting device iPad plus or something like that

Devices with Windows 8 RT are going to priced directly against the iPad. While the Windows 8 RT devices have Windows on them, The iPad is still stuck with IOS, This alone make so much business sense for apple to port OSX to the iPad.

One of the primary complaints of the iPad is that it does not have multiple account support , This is solved with OSX

With the rumours that there is going to be  a IPad mini, Apple might decide to have the iPad mini run on IOS and the iPad 10" run OSX

Apple brought PA Semi in 2008, PA Semi is a semiconductor company that specializes in energy efficient processors. It is possible that Apple might use a specially made SOC core to run OSX on the iPad.

Over the last few versions for OSX there have been many touch friendly features that have been introduced into OSX this could hit at an tablet running OSX

Sunday, May 13, 2012

Installing a new OS on a Compaq Presario B1800 with a dead CDROM

I had to install Xubuntu for a Compaq Presario B1800 that had a broken CDROM drive, I first tried to get it to PXE boot an ISO, That did not work as there is only 512MB of ram in it.

The next thing I tried was to connect  a external DVD drive and then tried to boot it, The external drive was not being detected.

The way to rectify this problem is to enable Floppy Disk boot form the BIOS and give it higher priority than the HDD. I have no idea why this works but it does work.

Wednesday, April 11, 2012

Prepping a new laptop for use

Today, A relative of mine got an brand new HP dm1 with windows 7 starter installed

This is what I did
1.Remove all the Crap that comes pre installed.
Stuff like
Norton Antivirus
HP Games Suite

2. Add new  stuff
Windows Security Essentials
Foxit PDF reader

3. Run windows update