Raspberry Pi – Low Cost HD CCTV Camera

Raspberry Pi as Low-Cost HD Surveillance Camera

By Christoph Buenger, DaSpors, 11 Oct 2013

Introduction

This article describes how to build a surveillance cam based on a Raspberry Pi micro-computer which records HD video when something moves in the monitored area. Live picture can be viewed from any web browser, even from your mobile while you're on the road.

What you will get:

· See live stream in any web browser from anywhere

· Record any motion into video file 

Usually, such a cam will cost you around US$2.000, but with the result from this article, you will get such a cam for only about US$100.

Background

Have you ever heard of Raspberry Pi? It's a low-cost micro-computer that is able to run Linux and has endless extension possibilities. It cost only about US$35 and opens up endless possibilities of what you can build with it. The official website can be found at http://www.raspberrypi.org/

Hardware components 

We need some hardware for this project. This is a list of the major things we need: 

· Raspberry Pi Model B:  This is the larger model of the Raspberry computer system with 700MHz and 512MB Ram. It supports HD video. Start here to see where you can order it in your country: http://www.rs-components.com/raspberrypi. Cost: about US$35

· Raspberry Pi Camera Module: This module was specially build for the Raspberry micro-computer. It has a connector to be plugged directly into the Raspberry board and supports HD video up to 1080p. The website http://www.rs-components.com/raspberrypi will show you where you could order it from your country. I.e. http://www.alliedelec.com/lp/130513rasocameramodule/ ships this camera in the US for only US$29

·  A housing for the camera:  you don't need to buy a high-price-housing for your Raspberry. There are loads of very cheap fake security cameras available which perfectly fit our needs here. Search the web for "surveillance camera dummy" and you will find loads of housings for your new camera for only a few dollars. I.e. this one will do the job: http://amzn.to/15XLaAj for only US$9. We have ordered this camera housing for about 20€ in Germany that had enough space for all the components: http://amzn.to/19CTEaN. You can use any camera housing, but only be careful about the size of the housing so that the Rasperry board will fit in there. The dimensions of the Raspberry board are 85.6 x 53.98 x 17 mm (approx 3.37 x 2.13 x 0.67 in). 

· Power supply: The Raspberry computer does not come with any power supply, you have to get one on our own. Any power supply with a micro-USB plug can do the job as long as it supplies 1A of power. We have ordered such a power supply plus a USB-to-micro-USB cable for about US$15: http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=70232557

· SD card: as the Raspberry Pi does not have any storage on board, you need to add some so that you can install and run the operating system for this device. Any SD or microSDHC should do the job, but we recommend using a Class 10 SD card. It's only around US$7

· To connect this cam to your network, you also need some kind of network connection. One possibility is to use a LAN connection, but you would need to put LAN cable to the point where you want to mount the camera. A better alternative is such a wifi USB adapter for only about US$10:

That's all: for about US$105 we have all the hardware we need to build this HD surveillance cam. 

Install Raspbian 

At first, you should install the OS and software to the Raspberry Pi before mounting it all together. An OS is the basic operating system software that tells the Raspberry hardware what to do. Linux is perfect for this. We have chosen Raspbian, as it's one of the most advanced OS for the Raspberry with loads of help and tutorials on the internet.

You need to prepare the SD card to be able to run Raspbian on the Raspberry: this excellent tutorial from Adafruit will explain the necessary steps.

Now temporarily connect your Raspberry Pi board to LAN cable, a monitor (HDMI TV works out of the box, but a HDMI-to-DVI cable like this will do the job as well) and a USB keyboard for the basic setup.

Insert the prepared SD card with the Raspbian installer on it and attach the power supply.

The Raspberry should boot up and guide you through the setup process as explained in this Adafruit tutorial. After this, you should have a basic Raspbian OS running.

Be sure to enable SSH in Raspbian so that you are able to control the Raspberry device also when there is no monitor and keyboard attached. 

Connect via SSH 

Now that the basic setup is done, you should connect to your Raspberry device from your computer. You can connect to Linux console from any computer in your local network and control it like you where sitting directly in front of it. This is very important as once mounted far away from your desktop, you need to be able to make updates and change the configuration of this camera any time later without the need to detaching it from the wall and bringing it back to your desk.

Remember that this cam is not just a dump cam device but a very powerful computer with Linux OS running on it. It's not limited to what we explain in this article now; it will follow any development in software so that you will be able to install updated software and more modules any time later.

First, you need a software to connect to the Linux console on the Raspberry. For Windows, you will need the extra (free) software PuTTY. Download it from the PuTTY website, install it and connect to your Raspberry Pi device:

From now on, you don't need any monitor and keyboard attached to the Raspberry anymore. 

Enable wifi 

If you want to run this camera with a wifi USB dongle (like we've suggested above), you will need to do some quick additional steps to make wifi work on the Raspberry: 

From the console (PuTTY window), edit the network properties of the Raspberry:

sudo nano /etc/network/interfaces

Now add these lines at the end of the file (or change existing lines to match these):

allow-hotplug wlan0

iface wlan0 inet dhcp

wpa-ssid "YOUR NETWORK SSID"

wpa-psk "WIFI PASSWORD"

(Fill in the SSID and password for your wifi network)

Reboot the Raspberry with this command and see if it correctly connects to your wifi network:

sudo reboot

Put the hardware together 

Now it's time to assemble all the hardware components together into the housing. Depending on the housing, this should not be a too complicated job:

As our housing had a very large glass window at the front, we have closed it with a black paper with a hole in it:

This also has the advantage that the red recording light of the Raspberry Pi camera module is not visible anymore. If you like the camera recording led to be visible, don't cover it. Whenever the camera is detecting any motion or is recording, the led light will glow in a very bright red.  

Installing the motion detection software 

A very good (and free) motion detection/surveillance software with many configuration options is motion. As the current version of this software does not support the Raspberry camera module yet, we've followed this special instructions to download and install a special build with support for this camera module. We're pretty sure that the official build of motion will shortly also support the Raspberry camera module as well.

A very important command to edit the motion configuration file is

sudo nano /etc/motion.conf

We've made some changes to the motion.conf file to fit our needs. Our current motion.conf file can be downloaded here: raspberry_surveillance_cam_scavix.zip

Some of the main changes are:

Make sure that motion is always running as a daemon in the background:

daemon on

As we want to use a high quality surveillance video, we've set the resolution to 1280x720:

width 1280

height 720

We don't need real-time video, 2 pictures per second are totally ok for our needs:

framerate 2

This is a very handy feature of the motion software: record some (2 in our configuration) frames before and after the motion in the image was detected:

pre_capture 2

post_capture 2

We don't want endless movies. Instead, we want to have max. 10 minutes slices of the motion videos:

max_movie_time 600

Enable access to the live stream from anywhere. Otherwise only localhost (= the Raspberry device) would be allowed to access the live stream:

stream_localhost off

If you want to protect the live stream with a username and password, you should enable this:

stream_auth_method 2

stream_authentication SOMEUSERNAME:SOMEPASSWORD

All configuration parameters are explained in detail in the motion config documentation.

Save videos on Windows shared folder

As the SD card of the Raspberry Pi is a pretty limited resource, we've decided to let the Raspberry cam store the videos on one of our Windows Servers. This is pretty easy:

First share a folder from some Windows machine. Just follow some guides on the internet if you've never shared a folder from a Windows machine before.

Then open the fstab configuration on your Raspberry from a PuTTY console or directly from the device:

sudo nano /etc/fstab

Now add an extra line with the configuration of your Windows network shared folder: 

//YOURSERVERNAME/YOURSHAREDFOLDERNAME /mnt/camshare cifs username=YOURSHAREDFOLDERUSERNAME,password=YOURSHAREDFOLDERPASSWORD,iocharset=utf8,file_mode=0777,dir_mode=0777 0 0

After a reboot, the Raspberry should have an extra folder /mnt/camshare mounted to the Windows shared folder. You should now set in your motion.conf

target_dir /mnt/camshare

so that motion saves all movies to the shared folder on the Windows machine.

Fix motion autostart 

We had some trouble that motion was not automatically started on a reboot of the Raspberry. We've found out that this was because the mounted folder of the Windows machine was not yet ready when motion tried to access it.

A very quick fix solved our problem:

Just edit the motion file with

sudo nano /etc/init.d/motion

and add the line

sleep 30

to the start-sequence:

Our changed /etc/init.d/motion script can be found in the attached raspberry_surveillance_cam_scavix.zip

Mounting the camera 

After all these steps, you can finally mount the surveillance camera to the destination point.

Some helpful hints: 

· Be sure to place the power supply in a dry and safe place

· Keep an eye on the wifi signal: if you mount the camera out of range of the wifi, it won't be able to send any video and motion videos  

Accessing the live stream

Now you can access the live stream from the camera from any browser via the url http://IPADDRESSOFRASPBERRY:8080 

Where 8080 is the port that we've configured for our stream in the motion.conf file. See your own configuration setting "stream_port" in motion.conf for the port.

We've found out that Google Chrome 30 (not even on iOS) was not able to play this stream directly due to a bug in the underlying Chromium project. But any other browser like Internet Explorer, FireFox, Safari and even VLC media player was able to show the live stream of the camera.
A workaround for this is to create a simple html file that contains one large image with the stream-url of the camera. See the file cam.html from raspberry_surveillance_cam_scavix.zip. This way, Chrome can show the live stream as well. Let's hope that Chrome will fix this issue in their browser. 

Access live stream from anywhere 

To make the live stream accessible from anywhere, you will need to enable some kind of dynamic domain services to your local network. This will enable you to always be able to connect to your local IP address from the outside even if your local IP address changes (over here in Germany, every private DSL ip address changes every 24 hours). 

Such a (free) service enables you to access your Raspberry from anywhere even if your ip address changes. A very good service we're using for some years now is dyn.com. They have some free services and are integrated in many routers. 

Once you have set up the dynamic ip url, you can access the camera stream from anywhere in your browser (i.e. http://YOURDYNAMICDOMAIN:8080):

And this also works from the browser on your mobile device:

Advanced steps 

There are a thousand things you can do with such a surveillance cam basic setup now. How about sending Growl notifications when some motion was detected? This guide explains how to add this functionality easily. 

Or you could easily add a temperature-sensor to the cam. It's only a few bucks and can be integrated very easily. 

We're currently working on integrating the live stream into MediaPortal server so that we can switch to a TV channel to see the live stream from the cam in our office.

If you want extra security, you could also add a battery pack to the camera. Be sure to buy one that is able to charge simultaneously while powering the Raspberry. This would enable you to detect if some bad guy cuts the power strips of your camera and send some alert messages to you (i.e. SMS or email) including the video of the disturber.

What are you going to add? Let us know!

History 

10/10/2013: Initial release of article

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Authors

Christoph Buenger

CEO Scavix Software Ltd. & Co. KG
Germany

Scavix Software offers high quality software development and consulting. That's what customers like Intel, AMD, eBay and Sage Software trusted in the last 6 years. Be it on the desktop, in the web browser, on a mobile phone, on a tablet or on the TV: we can make your software visions come true.
Are you our next customer? Don't hesitate to contact us.

Taken From: http://www.codeproject.com/Articles/665518/Raspberry-Pi-as-low-cost-HD-surveillance-camera

Expand Android Internal Memory with link2SD

In most of the Android phones internal memory remains low which is between 200-400MB. And in most of the cases generally the apps get installed in the internal memory so it take spaces and finally when internal memory becomes full your phone get slow or hanged. Though there is chance to install the apps in SD card but in most of the cases they get installed in the internal memory in default. So to get release from this problem the best solution is to use link2SD which let you install the apps in a separate partition of your SD card.

Let me show the way to expand internal memory with link2SD.

Requirements:

1. Your phone must be rooted. Rooting of your phone varies on your phone model.

2. There should have two partitions and you should backup files from the SD card.

3. Remove your micro SD card from the phone and using a SD card adapter, connect it to you computer, either directly our using an SD card reader (normaly USB)

Step 1: Create partition on SD card:

There are two ways to create partition. I recommend you to use Mini Partition Wizard Home Edition, it’s free. Linux fans use GParted.

I’m going to use Mini Partition Wizard Home Edition, but if you ruin your SD card and windows / Mini Partition, does not recognize it, use the GParted Live CD (miracle worker), if you don’t have linux installed.

Using the Mini Partition Wizard create the following partitions:

• Primary Fat32 Partition – Your normal SD card partition (with most of the sd cards space)

• Primary Ext2 Partition – The partition that will hold the Apps that you move from the phone’s internal memory. Mine was 1.5 GB, but it all depends on you needs and you sd card size.

• Primary Linux Swap – Used by linux for ram extension (something like windows pagefile), it should be at least as big as you phone’s RAM, mine is 512 MB.

Note: I used primary partitions but it’s possible that extended partitions migth work (didn’t test).

Now that we have completed creating partition now its time to configure link2SD.

Step 2 - Configuring link2SD:

· At first download link2SD

· Now install the app and launch it.

· When you launch the app it will ask to get superuser access.

· Allow the request

· Now it will as you to select the file system of your SD card’s second partition, select ext2 and tap OK.

· Now it will ask you to restart the phone, just tap OK to restart.

· After restarting your phone launch the link2SD app again.

· It will show you a dialogue, tap OK

· Now tap on the icon which you see in the screenshot and choose multi-select to select all.

· In this step go to Actions menu and select Create link then tick all the 3 options and tap OK

· Now configure the settings to create auto link in future.

· To do this go to Menu>Setting and Auto link and tick all the 3 options.

· Now exit the apps and forget about internal memory.

· To check memory status, launch link2SD and go to Storage Info.

Read more: http://www.androidever.com/expand-android-internal-memory-with-link2sd/#ixzz2gtFe3TfL

 

Based On: http://www.androidever.com/expand-android-internal-memory-with-link2sd/

Arduino PIR Motion Sensor / Detector

Make your own Arduino motion sensor / detector.  Maybe you want something to happen when you walk into a room, like have the lights turn on, or have your theme song play whenever you enter. This tutorial will show you how to get your to Arduino sense motion around it. Hardware used in this tutorial: · Motion Sensor for Arduino, with wire jumpers · Arduino board (Uno, Mega, Duemilanove, etc.) Instructions: If this is your first Arduino project, first go through our “Arduino: Getting Started” tutorial. Connections: Use the supplied male to female jumpers to make these connections: Motion Detector Pin Arduino Pin "-" GND "Out" Arduino Pin 2 "+" +5v Like this: Here is the front view of the module: Software: Download the example motion sensor for Arduino software here, and unzip the file /*      Motion sensor for Arduino, example code     Tutorial:  http://www.hacktronics.com/Tutorials/arduino-motion-sensor.html     Copyright: Mark McComb, hacktronics LLC     License: http://www.opensource.org/licenses/mit-license.php (Go crazy) */ const byte ledPin =  13;    // LED pin const byte motionPin = 2;   // motion detector input pin byte senseMotion = 0;       // variable to hold current state of motion detector void setup() {   // set the digital pin directions   pinMode(ledPin, OUTPUT);        pinMode(motionPin, INPUT); } void loop() {     // Now watch for burglers     senseMotion = digitalRead(motionPin);     if (senseMotion == HIGH) {    // burgler found!       digitalWrite(ledPin, HIGH);     } else {                      // no burgler, yet...       digitalWrite(ledPin, LOW);     } } or copy the blue text above to motion_sensor_for_arduino.pde file. You will now have a folder called “motion_sensor_for_arduino” Start the Arduino software and load the Arduino Motion Sensor example program by clicking File->Sketchbook->Open Navigate to the motion_sensor_for_arduino folder and select the “motion_sensor_for_arduino.pde” file. Transfer the Arduino Motion Sensor program to your Arduino board by clicking the “Upload to I/O board” button. After uploading, you should see the LED on the Arduino board light up whenever there is motion detected. It is that simple to add motion detection to your Arduino project. Remember, it takes about 60 seconds after you first power up the motion sensor before it stars to detect motion. You can adjust the amount of time that the motion detector lights the Arduino LED by adjusting the potentiometer screw on the back of the motion sensor module: Happy Hacking!

Based On: http://www.hacktronics.com/Tutorials/arduino-motion-sensor.html

Cisco to Huawei – Essential Command Mapping

CISCO	HUAWEI
ping	ping
traceroute	tracert
show	display
show interfaces	display interface
Show ip route	display routing-table
Show ip interface	Display ip interface
Show version	Display version
Show ip bgp	Display bgp routing-table
Show clock	Display clock
Show port	Display port-mapping
Show flash	dir flash: (on user view mode)
Show logging	Display logbuffer
Show snmp	Display snmp-agent statistics
Show frame-relay pvc	Display fr pvc-info
Show users	Display users
Show terminal length	screen-length disable
	undo screen-length disable
enable	Super
disable	Super 0 (number is privilege level from 0 to 3, where 3 is default and equivalent to “enable” on Cisco)
Conf t	System-view
exit	quit
end	return
Show policy-map interface	Display qos policy interface
send	send (on user view mode)
write terminal (sh run)	display current-configuration
Sh startup	Display saved-configuration
[no equivalent: shows the files  used for startup]	Display startup
Write erase	Reset saved-configuration
Write mem (or wr or copy run  start)	save
clear counters	reset (on user view mode)
	Reset counters interface
?	?
telnet	telnet
Enable secret (conf mode)	Super pass cipher (system mode)
Term mon	term debu
clock	clock
no	undo
debug / no debug	debugging / undo debugging
copy running-config	Save safely
terminal monitor	terminal monitor
terminal length	screen-length disable
	undo screen-length disable
terminal no monitor	undo terminal monitor
clear counters	reset counters interface
clear interface	reset counters interface
clear crypto	ipsec sa
	ike sa
clear access-list counters	reset acl counter all
reload	reboot
shutdown	shutdown
boot	boot bootrom
Aaa	hwtacacs scheme
terminal no monitor	undo terminal monitor
tacacs-server	hwtacacs scheme (in conf  command)
snmp-server	tftp-server (in conf command)
router bgp	bgp
Router rip	rip
ip tacacs	hwtacacs nas-ip (this  command doesn’t exist !!!)
mtu	Mtu (this command doesn’t exist !!!)
clear ip cef	reset ip fast-forwarding
clear ip route *	reset ip routing-table statistics protocol all
Clear ip bgp	Reset bgp all
Show tech	display diagnostic-information
Sh ip nat translation	Display nat session
Show Controller	display controller (but not relevant for non-modular chassis)
show dsl int atm 0	display dsl status interface Atm 2/0
sho atm pvc	Display atm pvc-info
debug pvc nego	Debug atm all (very dangerous – might crash router)
sho crypto isakmp sa	Display ike sa
sho crypto isakmp key	Display ike peer
sho crypto isakmp police	Display ike proposal

Taken From : http://lifeoflogs.blogspot.pt/2011/04/cisco-vs-huawei-essential-command.html

Step 2 - Sony Xperia Arc S - Howto Install Clockworkmod

So you have rooted your Sony Xperia Arc S and now want to flash a custom ROM? It’s definitely possible. But in order to do that, you’re gonna need a custom recovery, preferably ClockworkMod Recovery to allow installation of such ROMs and Mods. While the recovery provides options to flash new ROMs, it also lets you make backups of your current ROM to share with your friends or maybe use it to restore your device to the working condition if you’ve messed up with it. This guide shows how you can install ClockworkMod Recovery on your Xperia Arc S device and enjoy a whole new world of custom ROMs!

I. Before You Begin:

1. You must have rooetd your device before doing this procedure. Check out our procedure on Step 1 - Sony Xperia Arc S - Howto Root to root your device.

2. This works on Windows based PCs only.

II. Downloading Required Files:

1. RecoverX (Download link’s given in the first post)

RecoverX Mirror

III. Installing ClockworkMod Recovery on the Sony Xperia Arc S:

1. Place the RecoverX Tool archive onto your Desktop.

2. Unzip files from the archive over to your Desktop.

3. Enable USB debugging on your device by going to Menu>>Settings>>Developer options>>USB debugging.

4. Connect your device to your PC using the USB cable.

5. Double-click on the RecoverX’s executable file and it’ll launch.

6. Select Sony Ericsson from Brand dropdown menu in the tool.

7. Select Xperia Arc S from the Device dropdown menu.

8. Now hit the Next button and it’ll start flashing the recovery on your device.

9. Follow any prompts you see on your screen.

10. Once it’s done, reboot your device.

11. You’re all set! Excellent! Your Xperia Arc S has been successfully equipped with CWM Recovery and you now have endless possibilities to customize your device!

12. To access the clockworkmod menu, reboot you phone and while it’s booting, press “volume down” many times until you get the clockworkmod menu.

Based On: http://theunlockr.com/2013/03/31/how-to-install-clockworkmod-recovery-on-the-sony-xperia-arc-s/

 

Alternative Method (On Your Phone)

1. 1.Enable “USB Debugging” (Menu>>Settings>>Developer options>>USB debugging)
2. On you phone go to “Google Play”
3. 2. Search for “X-parts”
4. 3. Install “X-Parts”
5. 4. Run “X-Parts”
6. 5. On “X-Parts” go to tab “Installs”
7. 6. “X-Parts” will check te internet for a clockworkmod for your, if it finds the option “Install CWM” will appear
8. 7. Select the option “Install CWM”
9. 8. Wait, and it should be done
10. 9. To access the clockworkmod menu, reboot you phone and while it’s booting, press “volume down” many times until you get the clockworkmod menu.

 

How Root and Install Custom Roms on Xperia Arc S

• Step 1 - Sony Xperia Arc S - Howto Root
• Step 2 - Sony Xperia Arc S - Howto Install Clockworkmod
• Step 3 - Sony Xperia Arc S - Howto Install a Custom Rom (clockworkmod)

Step 1 - Sony Xperia Arc S - Howto Root

Root the Sony Ericsson Arc S (LT18i) with Android 4.0.4 ICS (Official Firmware)

This tutorial is intended for Sony Ericsson Arc S smartphones with Locked Bootloader .

Follow the steps that are on this page to check if the Bootloader is locked or not .

http://unlockbootloader.sonymobile.com/instructions

First check if you have the the Sony PC Companion (USB Drivers) installed so that you can the smartphone the PC , if they are not download here

Now let´s begin the process :

1 - The USB debugging option must be Enabled ( Settings / Developer Options / USB debugging ).

2 - The smartphone battery should be at least 80 % -85 % .

3 - Backup the data you have on your smartphone, just in case something goes wrong .

4 - Download FlashTool for Xperia Arc S and install on your PC here

5 - Download DooMLoRD_v1_Xperia-2011-ICS-ROOT-emu-busybox-su to your PC and extract with Winrar for example here

6 - Now download the kernel Android 4.0.3 (LT18i_4.0.3_kernel.ftf) here and Android 4.0.4 (Lt18i_4.1.b.0.587_kernel) here

7 - Connect your smartphone to your computer

8 - Drag the Android kernel 4.0.3 into the folder " firmware " which is located inside the Flashtool folder (C :/ Flashtool / firmwares ), open the FlashTool and follow the steps as in the images below:

In the image below is the list of firmwares that are in the Flashtool , select LT18i_4.0.3_kernel what it says and then just push “Flash” and wait for it to be installed on the smartphone .

The smartphone will restarting during this process .

9 - The USB debugging option must be Enabled ( Settings / Developer Options / USB debugging ).

After the smartphone to be powered back on, do the following:

• Enable the “USB Debugging” (Settings / Developer Options / USB debugging)
• Enable the "Unknown Sources" (Menu\Settings\Security),
• Run the file " runme.bat " we extracted in step 5 . The smartphone will restart 2 or 3 times, as part of the process .

Full procedure output:

10 - Now this process is similar to the step 8 , we drag the Android 4.0.4 (Lt18i_4.1.b.0.587_kernel) to C:/Flashtool/firmwares and do the same thing that was done in step 8.

In the image below selects what it says Lt18i_4.1.b.0.587_kernel and then just push “Flash” and expect it to be installed on the smartphone.

The smartphone will restarting during this process .

11 - If all has gone well , you now have your Sony Ericsson Arc S with Root

If PC Companion asks you to update just ignore.

If you update your phone will go back to the original stock rom (no root, no clockwork mod)

Based On: http://crimo-blog.blogspot.pt/2013/02/como-fazer-root-no-sony-ericsson-arc.html#.Ui5FyPJdZzM

How Root and Install Custom Roms on Xperia Arc S

• Step 1 - Sony Xperia Arc S - Howto Root
• Step 2 - Sony Xperia Arc S - Howto Install Clockworkmod
• Step 3 - Sony Xperia Arc S - Howto Install a Custom Rom (clockworkmod)

RAM Disks - Explained

Your computer’s RAM is still faster than even modern solid-state drives. RAM disks take advantage of this, using your computer’s RAM as a lightning-fast virtual drive. But you probably don’t want to use a RAM disk, anyway.

RAM disks are easy to sell — all you have to do is hold up performance benchmarks showing how much faster it is to read data from RAM than it is from even a fast SSD. But this isn’t the full picture.

What’s a RAM Disk?

To create a RAM disk, you would install a third-party program that creates a virtual drive in Windows. This program would reserve a section of your RAM — so if you had 4 GB of files in your RAM disk, the disk would take up 4 GB of RAM. All the files on your disk would be stored in your RAM. When you wrote to the disk, you’d just be writing to a different section of your RAM.

Initially, this seems like it could help optimize performance. If you installed programs in a RAM disk, you’d have near-instant load times because their data would already be stored in the fastest memory possible. When you save a file, it would happen almost instantly as it would just be copied to another portion of RAM. This would mean faster application load times and faster file read/write times for files saved in the RAM disk.

Why You Probably Shouldn’t Use One

However, there’s a big problem here. RAM is volatile memory. When your computer loses power, the contents of your RAM will be erased. This means that you can’t store anything important on a RAM disk — if your computer crashed because of lost power, you’d lose all the data in your RAM disk. So saving files to the RAM disk is pointless unless you don’t care that you’d lose the files — but if you didn’t care about the files, why save them in the first place?

Because RAM isn’t persistent, you’d also have to save the contents of your RAM disk to disk when you shut down your computer and load them when you turn it on. For example, let’s say you installed Photoshop to your RAM disk. You’d have to save an copy of your RAM disk to your computer’s hard drive to ensure you wouldn’t lose your Photoshop installation. You may want to do this automatically every few minutes or just at shut down.

When you turn on your computer, the RAM disk program would have to read the RAM disk image from your hard drive and load it back into RAM. In other words, you’re simply getting faster program-load times at the expense of longer boot-up times. Once your computer loads an application or other files form its hard drive, it caches them in RAM anyway — so it’s a bit silly to install an application or game in a RAM disk rather than on your hard drive. Either way, once you load the application, it will stay present in your memory for quick loading later.

RAM disks also reserve a good chunk of your memory, ensuring you can’t use it for anything else. Windows uses unused memory to cache files anyway, and it does it all automatically and in the background. If you need the memory for something, Windows will instantly discard the cached data. With a RAM disk, you’d have to shut it down manually to free up memory.

How You Would Make a RAM Disk

Making a RAM disk is pretty simple. Install a program like DataRAM’s RAMDisk Personal — the free version allows you to create RAM disks up to 4 GB in size — and use it to create a new RAM disk.

You can then install programs to it or move files to it. You’ll want to save a copy of the RAM disk so you won’t lose the data if your computer ever goes down. Of course you’ll have to save a new image every time you update the files on the RAM disk.

There Must Be Some Uses For a RAM Disk, But…

RAM disks aren’t a complete scam like PC cleaning programs and many other “system-optimization” tools are. It’s definitely faster to read and write from RAM rather than to use even a fast SSD. There are likely some good uses for RAM disks if you really know what you’re doing.

However, both of the following would have to be true:

· You’d have to be using a program doesn’t normally use RAM as a cache and instead insists on reading and writing small files to your hard drive.

· You’d have to not care about any of these files and have no problem if you lose them.

This is a high bar to clear — most programs that have a cache you don’t necessarily care about will use RAM, anyway. For example, there’s no point in placing Photoshop’s scratch file on a RAM disk because Photoshop uses RAM as a cache if it’s available. Your web browser will store its cache files in RAM if there’s space, too.

For programs that do write and read data from the hard drive, this data is likely something you don’t want to lose. Using a RAM disk with an important database would be a mistake because you’d lose the database if a crash or power loss occurred.

RAM-Based Solid-State Drives

If you do want to benefit from the speed of RAM, you may want to try investing in a RAM-based solid-state drive. These are solid-state drives that contain RAM instead of typical Flash memory. They’re much faster to read and write to, but also much more expensive because RAM is more expensive than Flash memory.

Such drives contain a battery, so they can maintain the contents of the RAM if the computer loses power. They  have enough battery power to write the data to offline memory, ensuring you won’t lose whatever you stored in their RAM.

Such drives aren’t for the average user — they’re extremely expensive options intended for data centers and other business uses where you want the speed of RAM with the stability of SSDs. But these drives make much more sense than software RAM disks if you really need RAM-like speeds for mission critical purposes.

In summary, RAM disks do work as advertised. But you probably don’t want to use them, anyway. They’re not ideal for running an important database or speeding up game load times.

If you do have a smart use for a RAM disk, leave a comment — we’d like to know what people are actually using them for.

Taken From: http://www.howtogeek.com/171432/ram-disks-explained-what-they-are-and-why-you-probably-shouldnt-use-one/