Hotplugging SATA Drives

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The SATA specification allows for SATA drives to be hotpluggable.

This usually allows manufacturers to create external drives that can be hot-swapped (via USB) more easily than with IDE drives. However, this usually also works for internal drives.

If you have an internal SATA drive (hard-drive, DVD drive, etc.) which is not connected to the motherboard and boot up Windows, not surprisingly, it will not show up in the Device Manager. If you then connect the drive’s data cable to the motherboard (and perhaps optionally) do a re-scan in Device Manager, the drive will then show up because the SATA controller detected the drive and made it visible to Windows.

This is great. If you accidentally forget to connect a SATA drive to the system and don’t want to shut down or want to create your own sort of external drive, this feature is very helpful.

Unfortunately, like most things, the pros come with cons. In this case, while the newly connected drive becomes visible to Windows and is usable, it will likely have poor performance. Windows loads the drivers for the drive on boot, so if you connect the drive after booting, instead of loading the tuned, high-performance drivers for it, it will end up using simple, low-speed access to (i.e., it will not use UDMA). You can see this as extremely slow transfers to/from the drive. If you do this with a DVD burner for example, it will be limited to ~2x even if you set it burn at 8x or whatever). You can also see this effect in the Task Manager’s Performance tab; the CPU load will jump when you use the drive, but no processes will spike because the load is coming from the kernel. This may or may not also occur in Linux or Mac.

So while SATA allows hotplugging drives, it doesn’t mean it will work well. Manufacturers will still need to provide a shim to allow for maximum performance and OS developers will need to better detect newly attached SATA drives and load the drivers at runtime.

Why (Evil) Ghosts Can’t Exist

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I like scary movies at least as much as the next person, and like most people, I too get a little creeped out and unsettled when going to bed in the dark after watching a horror movie. One fly in the ointment of horror however is the logical fact that evil spirits simply cannot exist.

There are two basic, low-level scenarios:

  • Ghosts do not exist at all (i.e., there is no after-life)
  • Ghosts can/do exist (i.e., there is indeed an after-life)

If the first scenario is correct, then there is no reason to fear ghosts because they just don’t exist under any circumstances, period.

What if the second scenario is correct and ghosts can or do exist? If ghosts can or do in fact exist, then there is indeed an after-life. If there is an after-life, then we have to examine the kind of ghost in question.

If the ghost (or the person who died) is/was good, then either they have already already ascended to Heaven, or they are only sticking around to take care of some unfinished business like getting their killer caught or looking after their loved ones. Either way, there is no reason to fear them (unless you killed them).

If the ghost (or the person who died) is/was bad, then why would they be allowed to stick around Earth and harass people? Shouldn’t they be forcibly pulled into Hell? Why would reporting to Hell for punishment be optional? Go straight to Hell, do not pass Go, do not haunt people or collect $200.

The only scenario that lets evil ghosts work is if you believe that there is an after-life and ghosts, but not believe in Heaven or Hell. There are not many cultures that believe in an after-life that does not include some sort of Heaven/Hell concept, but if you are one of those kinds of people, then you can still fear evil ghosts haunting you; otherwise, there’s no need to fear them.

You’re Not Dead Until You’re Dead

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Sometimes people have near-death experiences where they “die” for a while before being resuscitation. They are in some sort of accident or incident and are pronounced clinically dead, but come back after a few minutes.

Some of these people report seeing white lights, tunnels, gardens, dead loved ones, etc. while others report nothing. The ones who see something often end up becoming more spiritual and hopeful after their experience while the ones who saw nothing often end up becoming depressed and pessimistic, even if they had previously been spiritual.

The problem is that the people who see nothing decide that because they saw nothing when they “died”, it means that there is no after-life or Heaven or reunion with lost loved ones. This is absolutely specious reasoning.

These people are missing the point that they did not die. Why in the world would they be greeted with the post-life welcome basket if they are not dying and going to be resuscitated? Does it not occur to them that God would be smart enough to know if they are actually staying dead or not or do they think that they were supposed to die, but the doctors defeated fate/God and snatched them back?

Of course this raises the question of why some people do see things when they have a near-death experience. This is likely caused by differences in the nature of the near-death experience. Some people who are pronounced clinically dead have no brain activity while others do. The people who see things are probably not actually seeing post-life imagery, but rather hallucinations caused by a mix of their spiritual beliefs and their brain suffering anoxia.

The fact is that near-death experiences prove nothing about the existence or lack thereof of an after-life. Whether or not there is an after-life (at this point) is only knowable for sure by those who actually die, and stay dead, not by anyone who comes back, which of course, means that the living continue to have no definitive way of knowing either way.

Bigger Hard-drive = More Fragile

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In one of his podcasts, Steve Gibson of GRC discussed how his program SpinRite works to attempt to recover data from defective hard-drives. He mentioned that modern drives are more susceptible to failures now due to higher data density and smaller bit sizes. This is correct, but some people don’t know what that means, so as always, an analogy is helpful.

Hard-drives store data as magnetic binary bits. As a simplification, lets say that when the drive head writes a 0, it aligns the magnetic bit to positive and to write a 1, it aligns it to negative. However, the magnetic bit isn’t a single atom. Like everything else, it is made up of lots and lots of atoms. Just like how a fridge magnet is made up of millions of tiny atoms, drive bits are made up of lots of atoms that align together to give it a specific magnetic polarity that the drive head can read and interpret as a 0 or a 1.

Now for simplicity, imagine we have an old hard-drive in which each bit on the drive platters is made up of 100 atoms. When you write data to it, the write head tries to align the 100 atoms in the bit to the same polarity (positive or negative). However, this will not always work correctly and some of the atoms may not get aligned correctly (or at all). That is, the bits are either positive or negative which correspond to either a 0 or a 1 (this is a simplification.

In our old, 100–atom/bit drive, if eight atoms are corrupt and incorrectly written, then 8% is bad and 92% is good, so when the head reads the magnetic polarity, it gets a nice, solid, clear reading.

Some time goes by and data sizes go up, so hard-drive manufacturers have to make the drives bigger, but they cannot increase the physical size of the drive. Packing in more bits into the same size means using smaller bits (i.e., higher data density).

Lets say we now have a fancy new drive that is 5x the size of the old one. Instead of using 100 atoms per bit, our new drive has only 20 atoms per bit. As a result, if eight atoms are incorrectly written, then instead of only 8% of the bit being corrupt, it is up to 40%. We still get more correct than incorrect at that rate, but the margin is much smaller (even worse if there are more than eight bad atoms).

Some more time goes by and we get a drive with 10x the size of the first drive (2x the previous one). Instead of 100, or even 20 atoms per bit, it is down to 10. Now when eight atoms are incorrect, it is 80% bad and only 20% good! That means the drive used to be very stable with eight bad atoms per bit, but is now completely unreadable.

The reliability of the drive went down as the data density went up because while there is more data per drive, there is less data per bit which makes it bigger, but less reliable and more prone to corruption and data loss.

Monsters are People Too… Literally!

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Most of the classic monsters are not actually separate species but humans that have been damaged or changed somehow.

  • Vampires are just humans that have been infected with a virus
  • Werewolves are also humans that have been infected with a virus
  • Zombies are likewise virus-infected humans
  • Mummies are dead humans that have somehow come back (usually through magic)
  • Skeletons are the same as zombies/mummies, but without their flesh
  • Witches are humans who use magic (usually for evil)
  • Ghosts are dead humans

Even more contemporary monsters like Jason Voorhees, Freddy Kruger, Michael Myers, Pinhead, Chucky, creepy Japanese girls, etc. are just humans that have been changed in some manner.

Of course, there are some monsters that are not human whatsoever, for example the Creature from the Black Lagoon, Godzilla, demons, and such.

It is interesting however to realize that most monsters tend to be human. If one were to analyse that fact from a psychological viewpoint some interesting/obvious reasons would likely be found.

Ratings and Reviews are Essentially Worthless

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Reviews and ratings are common and can be seen everywhere. Reviews for movies, TV shows, music, video games, plays, books, cars, restaurants, you name it. However what most people don’t seem to realize is that most of the time, reviews are actually meaningless; at least free ones.

When it comes to reviewing or ratings things, there are two groups of reviewers: professionals and everybody else.

Professional reviewers get paid by magazines, websites, etc. to review things. Their reviews are generally useful because it is their job to write a review on the product/service whether they like it or not because they are being paid to do so. As such, their reviews usually do indeed reflect the quality of the thing in question. On the other hand, professional reviews are (as they have always been) susceptible to bias due to bribery.

Unfortunately, professional reviewers are few and getting rarer since thanks to the Internet, everybody and their dog can rate and review things.

There are two problems with reviews by amateurs (i.e., people who are not being paid to write it):

  • The quality of reviews by amateurs tends to be quite low. Most amateurs simply type up their general opinion instead of an objective, in-depth review (and this is assuming even a modicum of literacy on the part of the amateur which is increasingly elusive).

    Moreover, most amateurs seem not to even understand what a review is. Instead of typing up their opinion on the quality of the product/service, will simply describe it, basically just reiterating the spec-sheet/synopsis/etc. For example the vast majority of reviews on TV.com will just be an episode recap instead of describing whether the episode was good or not, likewise, on IMDB, many reviews will just describe what the movie is about. Useless—for some reason—they are giving a detailed scene-by-scene analysis, then these are completely useless and redundant.

  • Amateurs are not being paid to write reviews, so most will only bother to write a review if they either really loved it or really hated it. Most people don’t bother to write reviews for things that they liked unless they loved it so much they just have to gush about it. Likewise, people who did not like it don’t want to waste any more time on it than they already have, so they won’t bother writing a review for it unless they hated it so much that they need to vent and tell the world how horrible it was. People who thought it was so-so obviously don’t care.

    This results in a one of two kinds of reviews/ratings patterns:

    • Skewed in favor of it (you can see this in action on IMDB, TV.com, etc. where it looks like every show is great even though that is clearly not the case.

    • A polarized, bi-modal distribution where most of the curve is relatively flat with a sharp spike at the high and low ends, which may indicate the general attitude about the item, but not the actual usage. For example, a television show may have a bi-modal ratings graph, and people could on average feel that way about it, but it says nothing about how many people are actually watching, or likely to continue to watch, the show.

Professional reviews and ratings are—usually—reliable, but amateur ratings and reviews are generally completely pointless.

Quick, Easy, Cheap, and Safe Flea Removal

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If your pet picks up fleas, don’t bother with expensive chemicals and poisons, let alone needles. There is a much safer and cheaper way to get rid of them.

Simply get a lice-comb (like the kind that you use when children get lice at school). They are at the drug-store for one or two dollars. Comb the pet thoroughly a couple of times a day with the lice-comb to remove the fleas and their eggs.

In addition, wash your pet a few times a week (yes, even cats). Get a plastic box like a Rubbermaid storage container. Put it in the tub, fill it with warm, soapy water and soak your pet in it for a few minutes, massaging the (gentle) soap into their fur. Make sure to thoroughly soak them, but of course be careful of their face.

Finally, thoroughly vacuum all areas that they go to or use (blankets, beds, chairs, holes, etc.) a few times per week to prevent re-infestation.

To summarize:

  1. Comb with lice-comb a couple of times per day
  2. Soak and wash a couple of times per week
  3. Vacuum a few times per week

It may seem like a lot of work (certainly more than simply spraying them with poison or wrapping poison around their neck or shooting them full of chemicals with a needle), but it’s safer and cheaper and more reliable. Besides, if you stick to it, it does not take long and can be over in as little as two weeks.

Fight or Flight vs. Recognition

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I had an interesting experience with my cat. I turned around and saw her standing there, and because I was not expecting her to be there, I was surprised and jumped. It has probably happened plenty of times in different ways for most people, but the long and short of it is that sometimes we get shocked and react to something that is completely innocuous.

Why?

The brain has different parts that are responsible for recognizing things (especially faces) and for reacting to danger. One part is responsible for “fight or flight” whereby the body almost entirely automatically reacts to perceived threats. Another part is responsible for analyzing visual input and determining what is being looked at.

This scared-by-the-familiar response is very revealing and to be honest, not surprising. It shows that the part of the brain that detects and reacts to danger functions at a “lower-level”, a more base instinct and thus faster and at a higher priority than the part that recognizes objects which is a somewhat higher-level function (though obviously not exclusive to humans). This is not a surprise because fight-or-flight is a survival instinct and more important (at least more immediate) than object/person recognition.

Firmware Upgrade Safety

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Updating firmware is still often a somewhat risky task. The firmware is the software built into a chip in the hardware that provides the low-level functionality (drivers are the higher-level software that provides more advanced functionality).

The problem with updating firmware is that if the update does not go perfectly, this can leave the device in an indeterminate state without the ability to even try again since the low-level functionality is needed to upload firmware to the device in the first place.

In the old days, flashing a new BIOS or CD drive firmware was quite risky and resulting in much “bricking” (rendering a device useless). (Technically, there are usually ways to restore a working copy of the firmware like the manufacturer did in the first place, by cracking the device open and connecting to special ports on the motherboard (e.g., JTAG). Not surprisingly, manufacturers have tried coming up with better, safer solutions. Yet, updating firmware, especially with untested or third-party firmware remains risky to this day.

This is silly because there are numerous ways to prevent bricking devices.

One method that some manufacturers have implemented (usually on motherboards) is to use two BIOSes on the board. That way, if the main one fails, then the user can hold a special key combination or short a specific jumper or some such to restore a copy of the non-writable ROM backup to the erasable one.

This method is effective and can even be adapted in another way. Instead of having two copies of the firmware, simply have two flash drives. That way, when you upload a firmware, instead of being written to the main chip, it is saved to the storage chip, then if and only if it was successfully uploaded, it is quickly written (“flashed” if you will) to the main one. This way, the device can easily detect if the upload failed and provides an all-or-nothing flashing experience (an atomic transaction/operation in database parlance).