Simplifying Active Directory password on Samba

Written on Wed, 27 July 2016

I often find the password security for simple usage a little overkill. Of course, the security is deliberately set high for our protection, and is highly discouraged to be lowered. I'm not endorsing lower password security. But if you need to simplify your Active Directory password for your user accounts, use these commands:

sudo samba-tool domain passwordsettings set --complexity=off
sudo samba-tool domain passwordsettings set --history-length=0
sudo samba-tool domain passwordsettings set --min-pwd-age=0
sudo samba-tool domain passwordsettings set --max-pwd-age=0

By this, password complexity won't be required, you can reuse old passwords, and you never have to change password due to expiry. Much less administration, if you ask me.

Have an encounter with the Ark

Written on Mon, 18 July 2016

The Ark, subject of many controversy, finally has a life-sized version exhibition located America. It's a grand museum highlighting Noah and his family aboard the Ark during the global flood, along with all the animals. The team sure has built a fantastic exhibition.

But why?

Why go through such lengths to built such a grand exhibition for just 1 story? Isn't the story of Jesus far more important than any other story mentioned in the Bible? It would seem like a great waste of resources to feature a life-size Ark when you can depict a story in pictures easily, and the message will still get across. It's a bedtime story about an event that happened too long ago.

To understand the lengths the team behind ArkEncounter go through, it is important to know that no part of the bible is less important than any other. The bible is important from the first word, to the last "Amen". To better organise the Bible, we have segmented the bible into chapters and verses, like how we segment our textbooks in school. The segmentation is not a division of importance, merely organisational purpose.

Genesis Challenged

In the recent century, the first book of the bible has been heavily intellectually challenged, and rightfully so. After all, we have been taught that all living creatures roaming Earth today can be traced to a single-cell organism. Through many millions of years of mutation and natural selection, we have all the variety of species today. This is in contrast with the idea that God created the Earth and everything in it in 6 days.

Genesis is the foundation of the bible. Remove the book of Genesis and the purpose of Jesus on the cross is lost.

Thus the team behind ArkEncounter has gone through great lengths to defend the book of Genesis. The ArkEncounter is merely 1 of the many things they've done to defend the word of God.

Frequently challenged ideas of the Ark

How do you fit 8 million species into the small Ark?

We are taught during science class that there are many species of creatures. When we look at our common household pet dog, we have chihuahua, golden retriever, rottweiler, boxer, husky, and many others. It does seem indeed that Noah would have to figure out how to keep that many dogs in the Ark, on top of so many other animals.

But the bible says that Noah has to gather every kind. Gen 6:20 It is important to know what "kind" refers to. God isn't commanding Noah to bring every different variety of dogs onboard the Ark, but instead bring 1 kind of dog. Strictly speaking, it's actually a wolf, because dogs descended from wolf species. When it comes to elephant, not the many varieties of elephant, but 1 kind of elephant. And so on and so forth.

God also didn't common Noah to bring every kind of living thing on Earth into the Ark, only living creatures. (Genesis 6:19–20; 7:2–3) That excludes plants, bacteria, and fungi. The only plants Noah brought onboard were mostly for food for his family and the living creatures he brought along. The rest are presumbly left outside. Fishes are not brought along as Noah was not commanded to build an aquarium. Logically speaking, fishes wouldn't have any problem surviving a flood. Insects are quite possibly onboard the Ark, and they probably don't need so much space. The spider just need to make its home at the corner of the room.

All in, there is probably only about 1000 kinds of animals that need to bring in. The rest of the variety of species we have today are derived from the genetic mutation and natural selection over the years after the flood.

How did Noah keep that many massive animals on the Ark?

Noah didn't have to. He can bring in only younglings of every kind of animal, which in most cases, are significantly smaller than their adult. Remember that the Ark's goal is to allow Earth to be repopulated after the flood. The choice of taking younglings would be logical, as they have better reproductive value than their aging adult.

Were there dinosaurs on the Ark?

Yes. About 1000 years have passed since creation. A few kinds of dinosaurs would likely still survive and they would be brought into the Ark. They don't exist anymore, likely due to the condition of the Earth after the flood. The climate has gone through a massive change that many animals, including the dinosuars, would have died out due to the inability to adapt. As humans, we are also likely to kill an animal that would harm us as form of protection. That would have withered the population of dangerous animals.

It's also worth noting that after the flood, humans finally have permission to eat meat. (Genesis 9:3) Therefore, animal killings for food could also wither certain animal populations to extinction.

Did Noah bring 2 animals of each kind or 7 animals of each kind?

A shallow reading of the 2 chapters would seem like there is a contradiction in the bible.

you shall bring two of every sort...male and female Genesis 6:19

You shall take with you seven each of every clean animal, a male and his female; two each of animals that are unclean, a male and his female; also seven each of birds of the air, male and female, to keep the species alive on the face of all the earth. (Genesis 7:2-3)

Noah did both. In Chapter six, God is commanding Noah something very logical, you can't properly repopulate earth with only 1 gender. You need 2 gender, male and female.

Biologically speaking, all it takes is 1 male to impregnate many females of its kind. So when God commanded Noah to bring a male and his female, it would mean 1 male and 6 other females of every kind of clean animal. That makes better sense to quickly repopulate Earth.

Bill Nye visited Ark Encounter

It's really good to see a brilliant scientist such as Bill Nye in the Ark Encounter Exhibition. I would imagine that the conversation would be intense at some points, given that Ken and Bill have very different worldviews.

I would certainly want to visit this exhibition one day.

Juno uncovers creation secrets

Written on Wed, 13 July 2016

On 5th August 2011, NASA launched Juno, a spacecraft containing 9 scientific instruments, to Jupiter. After a 5 year journey, it has arrived and entering its orbit to begin mapping Jupiter.

Now, to understand why Juno mission, one must understand the importance of Jupiter in our solar system. From our human perspective, Jupiter is the second most important planet in our solar system. It is the largest planet, so large that all the other planets masses combined and Jupiter is still larger by 2.5 times. Our gas giant has the mass of 1/1000 of our sun, so massive that its barycenter with the Sun lies above the Sun's surface at 1.068 solar radii from the Sun's center. Jupiter affects a lot of things in our solar system.

The mission is the find out how the the solar system was created. Now, it is important to remember that we do not have a clue as to how the solar system is formed. Many scientist have come up with various hypothesis to explain the creation of Jupiter, and thus everything else in our solar system. Here's 2 popular hypothesis:

• Grand Tack Hypothesis
• Nice Model

These hypothesis didn't take into account of creation in Genesis. In the bible, we know that God spoke, and everything came to be. Honestly, I speak many things, but I've never observe me creating anything other than sound waves and some personal motivation! Regardless, we don't really have a clue as to how God create our solar system, and literally, everything else in the observable universe. I'm not going to come up with any hypothesis to suggest anything.

Juno's mission is scheduled to last for 20 months. Let's hope we can get answers to understand our solar system, and perhaps have a better clue about our past.
Follow Juno's mission @ NASA

Favicon Online

Written on Tue, 5 July 2016

There we go. Favicon is now online. It's my logo. Maybe I might change it a bit, but for now, that's my logo.

Adsense just rejected my site again. I don't understand. Why are they so picky? Fine! If they don't like my site, I don't need them to like my site. I'll just like them myself!

Strange memory hog in Ubuntu 16.04

Written on Sun, 3 July 2016

Ever since I booted up my Ubuntu 16.04 on AWS EC2 T2.nano to host this site, I often have a problem with kswapd0. It's a very strange occurance. I've been investigating this issue for many weeks. Each time, I come back to not much information to resolve this permanently.

Whenever I check my memory with this command

top

I see kswapd0 utilising almost fully all of the CPU cycle. As you know, t2.nano is given limited amount of CPU credits to use. This CPU cycle spike that doesn't resolve will consume all of it within a few minutes.

If you're experiencing this issue too, the recommended solution is of course to migrate to a better instance. But if you're like me, already bought down a reserve instance and refuse to be defeated by some strange programming logic in Linux, here's some of the things you can do.

Clear the cache every interval

*/5 * * * * echo 3 > /proc/sys/vm/drop_caches

Use this piece of code in your cronjobs. This will force the cache to clear every 5 minutes. This is the number 1 thing that you need to do. It's not 100% solution but it will almost immediate bring down the occurance of this CPU spike to once a month or so.

When the CPU cycle spikes, do the next step.

Check which application is consuming a chunk of memory

top

This command won't help to identify which application is using memory. Use this instead:

htop

You might need to install it:

apt-get install htop

In the interface, you need to sort out the application using the most memory. In my case, it was mysql that was consuming a lot of memory. What I needed to do was just restart mysql and the CPU cycle goes back to normal. In some cases, you might need to terminate the application. Do so with caution.

Update your linux installation

This isn't exactly a solution. Since I don't know the exact cause of this problem, perhaps let's keep Ubuntu and the relevant applications constantly updated with the latest bug fixes. Who knows the makers of the application spotted this problem and issued a fix.

apt-get update
apt-get dist-upgrade
apt-get autoremove

Usually I would do a reboot after this installation, just to be extra sure that the newest codes are running. Given that we have no clue why this problem occurs, being on the safe side pays.

Reboot the computer

You have been clearing the cache. You tried to identify the offending application and resolve it. kswapd0 is still eating away all your precious CPU cycle.

You are not alone. This is your last resort. Reboot the computer with:

reboot

Then you make sure all your services are back up and running.

Permanent solution needed

If there is anybody who has a clue what causes this strange CPU spike, please do share.