Tech

You are currently browsing the archive for the Tech category.

VPS hosting is available, affordable, and just a little bit scary.  In order to alleviate some of risk that is taken when moving to a VPS that is not under our benevolent control, we need to set up a reliable data backup solution.  The setup that I incorporated involves a server in the cloud backing up to my box.com account.  To accomplish this on CentOS 6, you can just use the following commands in a script that is executed periodically:

 

#!/bin/bash
HOME=/root
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
echo “Files backup to cloud”
eval $(gpg-agent –daemon)
export SIGN_PASSPHRASE=””
export PASSPHRASE=””
export FTP_PASSWORD=”your password”
echo “Files backup to cloud”
duplicity –use-agent –encrypt-key YOUR_ENCRYPTION_KEY –full-if-older-than 4M /var/spool/duplicity/ webdavs://YOUR_BOX_COM_ACCOUNT@dav.box.com/dav/lynetSky/duplicity && duplicity –use-agent –encrypt-key YOUR_ENCRYPTION_KEY remove-all-but-n-full 4 –force webdavs://YOUR_BOX_COM_ACCOUNT@dav.box.com/dav/lynetSky/duplicity && duplicity –use-agent –encrypt-key YOUR_ENCRYPTION_KEY remove-all-inc-of-but-n-full 2 –force webdavs://YOUR_BOX_COM_ACCOUNT@dav.box.com/dav/lynetSky/duplicity
echo “Database backup to cloud”
duplicity –use-agent –encrypt-key YOUR_ENCRYPTION_KEY –full-if-older-than 4M /var/spool/holland/ webdavs://YOUR_BOX_COM_ACCOUNT@dav.box.com/dav/lynetSky/holland && duplicity –use-agent –encrypt-key YOUR_ENCRYPTION_KEY remove-all-but-n-full 4 –force webdavs://YOUR_BOX_COM_ACCOUNT@dav.box.com/dav/lynetSky/holland && duplicity –use-agent –encrypt-key YOUR_ENCRYPTION_KEY remove-all-inc-of-but-n-full 2 –force webdavs://YOUR_BOX_COM_ACCOUNT@dav.box.com/dav/lynetSky/holland

 

These commands will instruct duplicity to make a full backup every four months (–full-if-older-than 4M).  When this script runs in the in-between times (say 2 months after the last full backup), it will create an incremental backup.  Duplicity will keep four full backups.  This is specified by the remove-all-but-n-full 4 directive in the command.  Specifying remove-all-inc-of-but-n-full 1 tells duplicity to remove all incremental updates except in the case of the last two backup set.  A backup set includes the last full backup and its incremental backups.  Yes, this is a bit complicated.  Yes, it is worth it.

The end result is this: in sixteen months, there will be four full backups (a new full backup is created every four months).  The newest two of these will have the incremental backups as well as the full backups.  This way, file history will be completely preserved for the most recent eight month period.  If we are really desperate, we can recover a file that twelve months old or sixteen months old.

We need to consider what happens at month seventeen.  We will have four full backups, the oldest full backup will be seventeen months old.  We should not expect to be able to recover files that are over sixteen months old.  When we continue on to our twentieth month  the oldest full backup will be removed and we will be back to only having sixteen months of recoverable data.  Always think of your maximum time to recover a file as (–full-if-older-than 4M * remove-all-but-n-full 4 == 4 months * 4 full backups = 16 months of full backups).

Storing four full copies of the data on a backup is (most likely) overkill for what I am doing.  These options were added when I decided that a full backup on another server lacked one thing: files that were deleted on the server were never deleted in the backup location.  Then, of course, my mind wondered into using rsync instead of duplicity.  It’s true, if all we need is a single backup of the files, rsync can provide a better solution (I do this with my personal photos and videos at home).  However, the point in time snapshot duplicity provides can be used for forensics and change tracking.  This solution as scripted above isn’t one size fits all.  Use the tools and settings that work the best for you.

This setup absolutely saved this site and the other sites I run.  The SAN that this VPS (at the time of this writing) is running on became corrupted and all of the data would’ve been lost had I not used an external site for backups.  If you are someone who is worried about the security of your backups, remember that duplicity has an automatic encryption algorithm built in.  Security of your data is there, just make sure to backup your keys so you can read the files.

To conclude: backups can save you important information; the cloud is a great place to store your backups; duplicity is a great tool that can automate this process.

Tags: , ,

Ah yes, time to get back to technology.  Today, I will try to persuade you to only buy a Chromebook if you are in a very select group of individuals.  This group is smaller than I had thought before.  In fact, I would say that the OS on these devices are crippled.

A Chromebook will work if you use all Google products and that is all you would like to use.  All others should look elsewhere.  Yes, there is a convenience factor as well.  The niceties fade quickly though.

My first though was that the device would make a good media player.  It is a good media player — if and only if you only watch videos from the Internet.  If you have your own media files you would like to play, they may or may not work.  The only video player you get is the one provided with the device.  It is limited in its capabilities.  It would play some of my home movies with video and no audio.

One of the biggest disappointments with Chrome OS is that it is strictly an Internet OS.  Note that it is not an Intranet OS.  You cannot share files through common methods with computers on your local network.  Please keep that in mind.  It is one of the biggest differentiators between Chrome OS and a typical OS.  For me, it is a deal-breaker.

The other flaw of the device is hardware related.  There should not be a fan in any Chromebook.  We are used to not expecting fans in these cheap devices.  We have the expectation of silence.  Some Chromebooks deliver on this, others don’t.

Chromebooks are cheap and provide good hardware for the money.  At the end of the day, it comes down to the question, “Can I be productive with this device?”.  My recommendation would be to go with a device based on Android instead.  An Android device is far more capable and will, most likely, enable you to be more productive.

Tags: ,

Not much to this post.  I stuck with the MSI card because it stressed quietness and coolness.  Some people have found out that the MSI card is too big for their case.  It isn’t really that much bigger than the EVGA card.

Why on earth is the vendor of a table to crucial?  That is a great question.  One that I hope to shed some light on in this post.

The vendor determines which features your tablet will include.  If the vendor provides storage in the cloud, they are more likely to not include a slot to put an additional storage device in.  If they have their own application store, they are more likely to include it and act like a competitor’s application store simply doesn’t exist.

Vendors are crucially important.  When they stop supporting a device, you must depend on someone else to provide updates, or throw the device away.

Tablet makers vary greatly in how long they provide support and what type of support is provided.  The cheapest tablet I have purchased had zero updates.  That is not a typo.  What you bought was what you bought and it was never updated.  This was worse then expected.  However, it makes a statement about what the vendor thought about the device; to them, it was disposable.

I am convinced that vendor support is directly related to a companies’ business model.  I have purchase a table from a vendor whose only way of making money was by selling hardware.  They don’t make money off of music, video, or application sales.  What do they care their device brakes?  A company like Amazon or Apple is more likely to give you support simply because they want to maximize their profit earning opportunities.

To wrap this over-thinking post up in a sentence: “Be sure to trust the vendor you purchase from”.  Read about their reputation for providing support.  Don’t be surprised that they leave out features.  All vendors I have come across do.

Tags:

It is a little known secret that a tablet without applications is like a television with no channels.  It really doesn’t serve a purpose.  This is a lesson I had to learn the hard way.  Don’t make the same errors I did.  Know which application store comes with your android tablet.

The most common application store for android tables is the Google Play Store.  If your tablet comes with this installed, you are all set.  Unfortunately, a lot of tablets do not include the Google Play Store.  This occurs for various reasons.  It also leaves the tablet at a huge disadvantage.  This was the case on my first and second tablet purchases.

Thankfully, there are other application stores out there.  The first that I would recommend is Amazon’s app store.  Just browse to http://amazon.com/getappstore and install.  Amazon is great for their free app of the day.  A paid application for free every day.  Sometimes, this is a really useful application and other days, well, it’s essentially a scam.  Be sure to read the reviews before installing.  Amazon is also well known for the restrictions they put on running the applications.  If you are not logged into Amazon, the application may not run.

Another application store that I use is http://1mobile.com/ .  1Mobile is great if you need the Google Applications such as the Maps and Music applications, but do not have the Google Play store.  I have used it to install Google’s Music player on my MID7042 tablet and it works well.  They have tons of applications in their store.  If it is in Google’s Play Store, it most likely will also be in the 1mobile market.  The only reason I have the Amazon store listed first is that I trust them more.  A great tutorial on installing the 1mobile market can be found here.

Your tablet is naked without applications.  Use one of the following application stores and you will be up and productive even if your tablet didn’t come preloaded with a sufficient application store.

Tags:

There are a lot of choices when buying a tablet.  Manufactures are pumping them out in all different shapes and sizes.  Are you going to buy a tablet that you later regret?  Read on and I will guide you through a few considerations to help you on your journey.

1. Screen

The screen of a tablet is important for a number of reasons.  Like laptops, a smaller screen means more portability and better battery life.  A larger screen means that you can actually read what is on the screen.  Make sure you are comfortable with the way the screen looks.  It is something that you cannot change after purchase.

One more thing of note, a screen with a lot of pixels on it (aka. HD, Retina)  will have to have the video card in the device to push that screen.  In human terms it means the better screen is an indication that the other parts of the table are high quality.

2. Speakers

This is a huge problem with current generation tablets.  If you want to watch a movie in comfort, you hold the screen in landscape format (like a TV).   The problem with this is that most tablets will only have sound coming out of one side of the screen.  This is the case, even when they advertise stereo sound.  Tablet makers expect you to use earphones and neglect the speakers.  This is true even in the more expensive versions.  Don’t be caught off guard by this.

3. Outputs and Inputs (HDMI and Expandable Memory)

Do you want to plug your new Nook tablet into the television?  You can’t!  Not without an adaptor that sticks out about an inch and will cost you some money. HDMI out is not an option, it is a necessity for most people.

One way tablet makers (like Google) try to push their cloud storage subscriptions (and raise profits) is by not providing expansion through memory cards.  Make sure you know how much storage you need.  Again, don’t get caught by this scheme.

As always, do your research.  Reading this post is a good start.  If you have any questions, please ask.  Happy buying!

Tags:

If you are like me, you are wondering why, after massive advances in almost every realm of technology, does your wifi range disappoint. This has been an issue for quite some time. Even top of the line equipment is not immune from poor range issues. There is seemingly no way to improve things.

The issue of wireless range is incredibly complex, but not unsolvable. There already exists several sites that cover the steps one can take to gain the best signal possible.  The route I chose to take was to add an external antenna.

Here are some pictures of the project.  I purchased a WNDR-3800 and used the antenna mounts to add the external antenna. The antenna is a TerraWave – 2.4-2.5/5.1-5.85GHz 2.5/4.5dBi MIMO Omni Antenna (part #M6025045MO13602).  I needed an antenna that did both 2.4Ghz and 5Ghz frequencies and MIMO to match the wireless router. To tie them together, I purchased four IPX / u.fl to RP-TNC female(male pin) bulkhead pigtail cables (Yes, all of that describes one cable.  Determining the correct one was tedious work).

 

IMG_1490

IMG_1491

IMG_1497

IMG_1501

IMG_1500

The result of the mod has been the elimination of all dead spots in the house.

The project itself wasn’t too hard to complete.  What is hard is understanding all of the math involved in determining wifi signal.  There are so many factors involved.  Even the length of the cables that run to your antenna may effect the signal.  If I have taken away anything from this project, it is that it is much easier to just go out an purchase a different wifi router then to mod an existing one.

Along those lines, here are two huge recommendations when purchasing a wifi router:

1.  Buy something that scored well in small net builder’s charts and don’t worry about anything else.  As of today, the RT-N66U is what I would recommend.

2.  Buy a wifi router with removable antennas.  You may be able to use antennas that throw the signal in a way that is better suited for your needs.

Tags:

Lots of great stuff going on.  The one that I’m writing about today is my desktop system upgrade.  There is a stark reality when buying computer hardware now-a-days.  “You are not fast enough to keep up with your computer.”  It’s true.  There is nothing I can do to keep up with the speed of my computers.  If you are not into gaming or some other really resource intensive activity, I really cannot recommend that you go out and buy a $200+ processor.

Being that I am not the normal computer user, I don’t abide by the previous stated rule.  My main system has been running an Intel Q6700 for some time.  What a great processor it was! But, the time to change was now.

There comes a time when computer equipment gets old.  Old is, of course, relative.  In this case, old meant that it did everything fine, but after 5 years, something better has come along.

The operating system I run is built from scratch.  Everything that is installed is run through a compilation process that can take quite a while to complete.  This allows me to gain insights into how my computer runs that is useful for someone in my field.  The problem is that this process takes a significant amount of time.  A rebuild from scratch can easily take over a day.  That process needed to be faster.

To measure the speed difference on the new setup, I timed the building of one of the most important components of the system:

gcc build on old Q6700

real    28m7.051s
user    62m49.460s
sys    5m35.580s

gcc build on new FX-8120
real    18m57.720s
user    72m16.450s
sys    4m44.720s

It’s a single measure, so don’t take it as authoritative.  What I took away from this simple test is that my system is roughly 33% faster on this task.

So why choose Bulldozer CPU when all of the reviews say it is a disappointment?

Two of the reasons are already listed.  It’s faster for my uses, so it didn’t matter that it wasn’t the fastest.  The kicker was the price.  Sometimes, when you find a good deal, you get tilted in a specific direction.  This is especially true when I can’t max out the capability of either of the options anyway.

$333.33 went to the purchase of the FX-8120 CPU, ASUS Sabertooth Motherboard, and 8GB of ram (purchased in May of this year. Yeah, it took a while to get this post out of my head)

$179.99 was gained through the sale of old equipment

After subtracting some fees involved, I have about $175 invested in the upgrade.

Knowing that AMD is going to keep the same CPU socket for a few years and also knowing that the Sabertooth motherboard is still one of the best out there.  I am happy with the future prospects of this setup.

Tags:

Sometimes things don’t turn out the way I thought they would.  When the infamous $100 laptop project was going on (has it really been) 5 years ago, I thought that $100 laptops were the future.  Tablets were, so we thought back then, unusable devices that would never catch on due to clunky input and the fact they ran operating systems that were designed for laptops.

The iPad changed everything.  It turned out that when a operating system that was designed for a tablet combined with 1000’s of applications that were designed for use with a tablet made a pretty useful device.  Pretty useful as in it does about 75% of the things that can be done with a laptop and then adds its own capabilities such as a touch screen and accelerometer.

This was all well and good, but if you are like me, you were still clinging on to your laptop and saying, “It still doesn’t do X”.  Times have changed, a touch screen combined with applications that work well with a touch screen has left me thinking, “My laptop doesn’t do Y”.

Then the tipping point came.  The team I am on was assigned to the development of a mobile application.  It was time for me to get with the times and try out a tablet.

You may be familiar with the ~$200 tablets such as the Kindle Fire and the Nexus 7.  They each have their strengths and weaknesses.  If you are like me, you want the best deal possible.  By looking around on the Internet, I was astounded to find out that the $200 price mark was beatable.

My first purchase was a $92 Coby MID7042.  My second was a $95 Viewsonic G-Tablet off of ebay.  I have found it!  The sub $100 computer. Both of these devices are great in their own ways.  Disclaimer: Please search the Internet for reviews before you make any purchasing decisions.

It seems unbelievable, but the time has come.  Even with the dollar’s purchasing power going down over the last 5 years, you can get a great piece of computing power for under $100.  Just look in the tablet section.

Tags:

Update 6/4/2013

A lot of people have had issues with this keyboard.  Mine is typing duplicate letters randomly.  I can not longer recommend that anyone purchases this keyboard.  The form factor is great. The execution, not so great.

Original Review

Keyboards have been boring.  Did you know that there are mice out there that you can put weights in so it weighs the exact amount you want it to weigh? I have such a mouse.  It frequently turns to my keyboard and has a good chuckle.  Thanks to the AZiO Levetron Mech4, that chuckle has been silenced.

The number pad is one of the least used things on everyone’s desktop.  Why does it exist?  Why is it not optional?  Why does everyone have to tilt slightly to the left all day so they can type?  Typically, the mouse is on the right side of the keyboard.  All the more reason to get rid of 4 inches of unused number pad. The mech4 makes the number pad optional.  What a great idea! It seems so profound when you buy a keyboard that actually has had this done.  This was the #1 thing that I was looking for in a keyboard.

The #2 thing I was looking for was anti-masking.  Most people would not care about anti-masking enough to even know what it is.  Let me explain it simply.  Hold down the ‘J’, ‘K’, ‘L’, and ‘;’ keys with your right hand, then hit any other key with your left hand.  Did the key you hit with your left hand actually type?  If not, you are experiencing masking.  This doesn’t usually matter.  Who hits 5 keys at the same time anyway?  The people who care are typically gamers.  I want to move to the upper left (2 keys), while walking (1 key), and casting a spell (1 key), and taunting the guy I am casting the spell on (1 key).   This was also an issue when I rewired an old keyboard to make two player arcade controls.  All of the sudden, one player couldn’t move.  It was because their movements were getting masked.  It seems like a feature that should just be there in a premium keyboard, but like the number pad, often overlooked.

With a keyboard that is going to cost over $100, you expect quality.  The #3 thing that I was expecting was quality.  With the Mech4, I knew going in that it was a mechanical keyboard with Cherry black keys.  That means that the keystokes were going to take a consistent amount of pressure to register.  There are a lot of keyboards out there that have keys that are not consistent with the pressure you need to press a key.  Test out your keyboard (I apologize if I have now made typing annoying for you :)).  Cherry black keys are also somewhat loud.  You need to know that going in.  It doesn’t bother me, and my cat is currently lying with her left-rear foot about 1/2 inch from the keyboard, so it’s not too much of an issue for us.  A co-worker may not be so happy about the noise though.

Those were the three major criteria for me.  There are a few keyboards that meet this.  And, as you already know, I purchased the AZiO Levetron Mech4.  It not only meets my three criteria, but it adds a few interesting changes from your normal keyboard.  There are programmable buttons on the left of the keyboard, a button to turn on and off the ‘windows’ key, a volume knob, and a neat little contraption that sits on the top of the keyboard and provides six additional programmable buttons.  The keyboard is a rock, the skid pads are huge so it doesn’t move around on my desk, and it has a built-in palm rest.

On the negative side, there are a few things they could improve.  The keyboard takes two USB connections and does not have any option for using a PS/2 connection.  The sides of the keyboard, where the number pad would plug in if I used it, take up about 2 inches of space on the sides of the keyboard that I consider wasted.  Back-lighting on the keys was not a show-stopper to me, but may be for some other users.  Unlike some people, I usually have the lights on when I am working or playing.

Finally, someone is paying attention to keyboards!  AZiO has made a product that should make other vendors take notice.  Perhaps, more innovation will come in the near future and we all can benefit from the creative thinking that has made its way into products like the AZiO Levetron Mech4 Keyboard.

There are other reviews on this product on-line.  Please check those out as well before making a decision with your money.  As you can tell my this review, I am quite pleased with the purchase.

Tags:

« Older entries