If your computer got stolen, how much data would you lose? Wedding photos, baby photos, important documents, photos of your recently deceased grandparents?
It’s vitally important that you have a backup solution ready for when disaster strikes, and one backup isn’t enough.
3-2-1 Backup
The basic principle of 3-2-1 Backup, is you have 3 copies of your data, stored on 2 different types of media and 1 of them is off site.
A good example of this is having one backup on an external hard drive at your house (local backup) and an online backup (offsite backup).
If your computer got stolen, how much data would you lose? Wedding photos, baby photos, important documents, photos of your recently deceased grandparents?
It’s vitally important that you have a backup solution ready for when disaster strikes, and one backup isn’t enough.
3-2-1 Backup
The basic principle of 3-2-1 Backup, is you have 3 copies of your data, stored on 2 different types of media and 1 of them is off site.
A good example of this is having one backup on an external hard drive at your house and an online backup.
Read more to find out about how to setup both a local and a cloud backup on a Mac!
So, my FreeNAS Server started randomly spewing my log file with this:
Dec 24 16:16:10 zoe kernel: arp: 43:05:43:05:00:00 is multicast
Dec 24 16:16:10 zoe kernel: arp: 43:05:43:05:00:00 is multicast
Dec 24 16:16:10 zoe kernel: arp: 43:05:43:05:00:00 is multicast
It was going at a rate of about 1 a second (in bursts of 5 every 10 seconds or so).
I fired up Wireshark to work out what it was, turns out it was my OpenMesh Wifi Access points sending these packets out.
My school got loaned a 3D Printer to borrow for a few weeks, now we’ve got a minecraft club. I figured I could combine the two!
The cool thing with being able to export Minecraft to a 3D Printer is that children can do it really easily without having to learn a 3D Design program.
I’ve done a bit with 3D Printing before, I bought myself a PrintrBot Plus when the Kickstarter for it was on, however I could never get my prints to work very well. I ended up giving the printer to some friends and decided that 3D Printing wasn’t for me. That was until my school got loaned an UP Mini 3D Printer. I did a test print and it just worked. Glorious.
The version of Minecraft we’re using at school here is called MinecraftEdu. It’s built for schools and gives you greater control over students (and cheaper licences). Continue reading →
A few years ago I bought a barcode reader for use in a school Library. It was a Cino 780BT, Bluetooth, nice base station, glorious battery. It was a really nice unit.
One slight issue: The trigger switch on them sucks. The first one we warrantied and got a replacement, the second one developed the same fault after a year or so of use too. The first time it happened the switch had come loose from the board, so I resoldered it back on (it’s a SMD switch, so there wasn’t much holding it on).
I contacted the company, they wanted me to send it back to them to fix (and charge me for it), the switch would be $20 + labour to fit it. I figured since it was out of warranty I’d give it a shot and see if I could replace it.
I couldn’t find a decent switch to fit (I tried to repurpose a switch from a mouse, but I couldn’t get it to fit right), so I used a switch from my Mechanical Keyboard sampler kit (it has 4 different types of switches to try out to see which one you like).
So: Little bit of soldering and some hot glue later, I have a working barcode reader again!
UPDATES! 21/6/14: Use a different interface that does just WAN traffic and made the cron thing actually work. Scroll down for the green bits (padavans firmware only though).
I’ve spent the last few days fiddling around with network traffic monitoring on my modem so I can track downloads for each different computer on my network. This article is a how to guide and a set of notes about getting it working.
If you want to follow this guide, you will need an Asus RT-N56U or one of the similar models. You can also mostly follow this guide using any OpenWRT routers (but you will need to adjust as you go to suit your router). I initially set it up using the stock firmware on the RT-N56U, however I ran into issues where it was reporting the wrong amount of traffic. After I installed the Padavan’s Firmware, I still had the same problem (I later solved it by disabling hardware NAT below). In theory this technique should work with the stock firmware and I’ll detail it below as well as how to get Padavan’s Firmware up and running too.
The final result of this is to be able to see a screen like this:
I recently got myself a MacBook Pro 15″ Retina and noticed that in Mavericks they have removed the option to have separate timers for display sleep and computer sleep. You can turn off sleep mode when you’re running on AC power, but not when you’re running on the battery.
The problem with this is that I want the display to turn off to save battery power, but I want all my background processes (eg. Adium/Colloquy) to continue running and for it to stay connected to wifi, but when the display goes blank, it goes straight to sleep and disconnects everything!
The fix for this is to manually set the options via pmset in the terminal. To do this, you’ll need to do the following:
1. Open Terminal (it’s in the Utilities folder under Applications)
2. Enter the command: sudo pmset -b sleep 0
3. Enter the command: sudo pmset -b standby 0
I’ve done this as both a Mac and PC guide, the PC way of doing it is actually a little easier (but I use a paid program for it).
I’m on a 100mbit connection with a 720p iSight camera on my MacBook, so it uses about 500KiB/s of uploads (+ whatever the person I’m talking to is sending me back) which turns out to be something like 2gb an hour. This being said, Skype runs just fine on 50-100KiB/s.
When you turn on the speed cap thing, give it a minute or so and Skype will automatically adjust the video quality to suit the bandwidth available to it, so set your limit, then chill for a bit and see if you’re getting the quality you want
Mac
You’ll need a program called Entonnoir (it’s a free one).
Download it, and pop it in your Applications folder.
In Skype, go to Preferences and check the port number under the advanced tab.
Now, in Entonnoir, hit the + button, set the port number to the same as the one in your Skype Prefs and set your limits.
PC
I use a program called NetLimiter. It is glorious and I use it a lot for scheduling downloads (like game downloads through Origin/Steam where there’s no scheduling function built in) to run during off-peak download times.
Simply open up NetLimiter, tick the button next to Skype and enter a limit in.
If you know of a free equivalent for NetLimiter, post it in the comments!
To download a torrent you need a client (ie. uTorrent) and a tracker (ie. thepiratebay.org). The tracker is simply a website that contains links to .torrent files (or the newer magnet links), these are very small files that tell your torrent client where to get the pieces of the file from.
Torrents are known as Peer to Peer (P2P), this means that you are downloading the files off other users (and not off one big server). The tracker serves to link all the users together and doesn’t actually contain any of the files.
Something to note: If a movie has only just hit the cinemas, you won’t always be able to find a good quality version of it (it will probably be mainly CAM/TS rips which aren’t worth downloading).
When searching for a torrent to download, you need to keep in mind a number of things such as how many seeders/leechers there are, comments about the torrent, whether the torrent has been uploaded by a VIP or Trusted Uploader and also the name of the torrent will give you a lot of clues as to what is in it.
VIP/Trusted Uploaders
This differs depending on what tracker you’re using, some torrent sites only allow Trusted Users to upload (these are generally private ones) and other sites can have a lot of untrusted users uploading things like viruses and fakes. If a file has been uploaded by a Trusted User, you can safely assume that the torrent is a good one (though you should still check the other things as well such as the name of the torrent).
To see if a torrent has been uploaded by a trusted user, you will see a marker on the torrent, for example with thepiratebay.org, you will see a little skull icon.
Torrent Naming
Torrent names are made up the name of the thing you’re downloading as well as a bunch of words to indicate the quality and the group that released it.
These examples are for movies or TV shows, but most other downloads will be similar.
They start with the name of the show, followed by the Season or Episode if it’s a TV show, or the Year if it’s a movie. The season is usually in the format S01E02 (aka. Season 1, Episode 2).
After this they will have the Source of the video, here are a few common ones: HDTV/PDTV = Ripped straight from the TV, you may notice a TV logo in the corner and sometimes the silly popover ads that you get when you’re normally watching TV. DVDRip = Ripped straight off a DVD, generally average to good quality. BDRip = Ripped off a BluRay, very good quality. WebRip = Ripped off a website, ie. Downloaded from iTunes or another video streaming service. CAM/TS = Recorded in the Cinema with a camera, avoid these, they’re usually really horrible. R5/R6 = These are DVD’s obtained by the movie company converting the film from the source onto a DVD, it is generally before any sort of processing is put on it, so quality is comparable to a Screener and a bit less than a DVDRip.
After the source is the format it is in here some of the common ones: 720p/1080p = These are high definition, usually the size of these will be greater and normally only comes from a BDRip or a WebRip. x264 = A video codec, this is usually used for high definition footage. XVid = An older video codec, a lot of non-high definition footage uses this.
At the end of the file name will be the release group. For the most case this doesn’t matter, though if you’re getting a series, it’s usually good to get the whole series by the same release group so the quality is the same throughout the whole lot (but really, it doesn’t matter).
Here are a few examples:
Packed To The Rafters S06E07 PDTV x264-FUtV
So you can see that this is Packed to the Rafters, Season 6, Episode 7. It has been ripped off PDTV (Pure Digital TV, aka it’s a rip straight off the TV), it is in x264 format and the group that released it is FUtV (for most people, this doesn’t matter, however some release groups you may see around often and know that they’re a good copy).
Kath And Kimderella 2012 1080p BluRay x264-PFa
Kath and Kimderella, the movie was released in 2012, it is a 1080p high definition copy taken from a BluRay and it is in x264 format. It was released by the group PFa.
Seeds
When downloading a file from BitTorrent, you connect yourself to a swarm of people who either have the file you want, or are currently downloading the file you want. The people who have the file downloaded 100% are called Seeds, and people who are still downloading the file are called Leechers. For torrents to work properly, you need seeders.
The torrent download is split into chunks, as you download chunks that make up the file, you will also seed (upload) them to the other Leechers. Even when you have finished downloading the file, it will continue to do this (so you become a Seeder instead of a Leecher). Common curtesy says you should seed the files you download to a ratio of 1 (this means you have uploaded as much as you have downloaded). Some torrent trackers (websites) will enforce a minimum ratio for your downloads, so you must seed them to a particular ratio or risk being banned from the site.
File Size
You should keep in mind how big the file is before you download it, a full 1-2 hour movie can be anywhere from 300mb (really poor quality) to 10-20gb (really high quality). Typically an xvid/DVD Rip will be 700mb to 1.2gb, a 720p will will be 3-8gb and a 1080p rip will be 7-20gb.
Comments
Still not sure about a torrent? Go have a look at the comments with it, if it’s a fake, there *should* be a bunch of comments stating this.
Nuked/Repack Torrents
If a torrent has been nuked, it means that there was something wrong with it. The problem can vary from major problems like missing footage or audio out of sync to simple things like being named incorrectly, glitching out for 1/2 second or so. Usually when a torrent gets nuked, there’s what’s called a repack or a proper. A repack is a fixed version of the torrent and will usually have REPACK or PROPER in the title.
Here’s a quick guide I wrote on how to use Photoshop to easily measure an area on a Map using Photoshop.
In this guide I’m using Photoshop CS5 for Mac, most of the concepts will be similar for the other versions.
First up: Scan your map and get it into Photoshop
Working out the Scale
1. If you’ve got a scale marker on your map, use that, otherwise you’ll need to measure a distance that you know, in this case I used a basketball court (marked as 20mx33m).
2. Use the Ruler Tool in Photoshop (hidden under the eyedropper tool) and select the distance for your scale.
3. In the ruler tool options (top of the screen usually), make sure “Use Measurement Scale” is unticked. Then look at the L1 value. Write this number down!
4. In my example I got the value 246.88px. So from this we can work out that there’s 246.88 pixels in 20 meters.
This gives us 12.344 pixels per meter and if we square it we get 152.374px per square meter.
Highlighting the Area
1. Make a new layer, and using a wonderful bright colour, paint over the area you want to calculate the size of. Make sure you set the brush to have a hardness of 100%.
2. Use the Magic Wand Selection Tool to select the area you just painted. Set the tolerance to 1 and untick Antialias and Contiguous (it should select everything you’ve painted).
3. Go to the Window Menu and bring up the Histogram. If it doesn’t have the numbers underneath it, click the drop down box in the top right hand corner of it and go to Expanded View.
4. Change the “Source” dropdown box in the Histogram window to Selected Layer and write down the number under Pixels. I got 157,529px.
Doing the math
So we know that one square meter is 152.374px and our selected area is 157,529px.
So we do some quick division: 157529/152.374 and we get 1033.83meters^2
If you used this or have any corrections, please leave a comment 🙂
