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Linux is a UNIX-like open source operating system with hundreds of distinct distributions, including: Fedora, openSUSE, Ubuntu, Debian, Slackware, Gentoo, CentOS, and Arch Linux. Linux is generally associated with web and database servers, but has become popular in many niche industries and applications.

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Often times it's very very easy to extend a volume on a Linux instance in AWS, but impossible to shrink it. I wanted to contribute to the experts-exchange community a way of providing a procedure that works on an AWS instance. It can also be used on any Linux virtual machine.
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This article will show you step-by-step instructions to build your own NTP CentOS server. The network diagram shows the best practice to setup the NTP server farm for redundancy.  This article also serves as your NTP server documentation.
Easy2Boot customized
I have written articles previously comparing SARDU and YUMI. I also included a couple of lines about Easy2boot (easy2boot.com). I have now been using, and enjoying easy2boot as my sole multiboot utility for some years and realize that it deserves an article all it's own.
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How big is your USB stick?
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by:Thomas Zucker-Scharff
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I use the recommended max size of 128gb.  The author of e2b says that you can put it on one as small as 16gb.  Of the 128gb (~115 usable) I have ~25gb free.  So you could get this on a 64gb stick by just getting rid of older versions (Ubuntu prior to 17.xx, Windows 10 prior to the last 2 versions, any other software with previous versions).  Just getting rid of old win10 versions would free up about 10-20gb.  Old praragon versions might take up an additional couple of gb.

I personally would not put e2b on anything less than 64gb, I prefer the extra room on a 128gb stick.
In part one, we reviewed the prerequisites required for installing SQL Server vNext. In this part we will explore how to install Microsoft's SQL Server on Ubuntu 16.04.
In the first part of this tutorial we will cover the prerequisites for installing SQL Server vNext on Linux.
Google Drive is extremely cheap offsite storage, and it's even possible to get extra storage for free for two years.  You can use the free account 15GB, and if you have an Android device..when you install Google Drive for the first time it will give you a link to get 115 GB for free for two years.
Fine Tune your automatic Updates for Ubuntu / Debian
It’s 2016. Password authentication should be dead — or at least close to dying. But, unfortunately, it has not traversed Quagga stage yet. Using password authentication is like laundering hotel guest linens with a washboard — it’s Passé.
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by:William Nettmann
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The Quagga is on it's way back - maybe the password will survive as well!

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Thank you all for your comments = passwords must die!
The purpose of this article is to demonstrate how we can use conditional statements using Python.

I. Introduction

There's an interesting discussion going on now in an Experts Exchange Group — Attachments with no extension. This reminded me of questions that come up here at EE along the lines of, "How can I tell the type of file from its contents?", as well as, "What kind of file has the XXX extension?" Writing an article to address this has been on my to-do list for a long time — the group discussion has inspired me to do it.

II. Determine the type of file from its XXX extension

Here are four links that can help in determining what an XXX file is:





Simply replace XXX with the file extension of interest. For example,





III. Determine the type of file from its contents

Now to the trickier question! An excellent file identifier application called TrID analyzes the contents of a file in an attempt to figure out what type of file it is. It comes in both a command line interface (CLI) version (for Windows and Linux) and a Graphical User Interface (GUI) version (Windows only) called TrIDNet. The downloads are at the links in the preceding sentence.

Both the CLI and GUI versions require a database/library of file definitions. This is a key feature of TrID and TrIDNet — the always increasing list of files that it recognizes. As of this article's submission date, the database contains 6,019 definitions (dated 13-August-2015). Note that there are separate downloads for the CLI definitions and the GUI definitions.

IV. More about TrID — the CLI version

After downloading the CLI version and its definitions, simply unpack the ZIP file with the program (trid.exe) and copy the definitions file (triddefs.trd) into the same folder as the program file. As mentioned above, using a database of definitions for file types is a really nice feature of TrID. Since file types are frequently added, the program author makes the definitions database available as a separate download, so you may go back to the website occasionally to get the latest definitions file.

Here's the syntax of the CLI version (v2.20):


Usage: TrID <[path]filespec(s)...> [-ae|-ce] [-d:file] [-ns] [-n:nn]
                                                                           [-@] [-v] [-w] [-?]
                                        Where: <filespec> Files to identify/analyze
                                               -ae        Add guessed extension to filename
                                               -ce        Change filename extension
                                               -d:file    Use the specified defs package
                                               -ns        Disable unique strings check
                                               -n:nn      Number of matches to show (default: 5)
                                               -@         Read file list from stdin
                                               -v         Verbose mode - display def name, author, etc.
                                               -w         Wait for a key before exiting
                                               -?         This help!

The program is free for personal use. Here's exactly what the license says (I took the liberty of correcting typos in it):

The program can be freely distributed and is freeware for non-commercial, personal, research and educational use. Contact the author for commercial use or commercialization of TrID or TrID's definitions and contained information.

I don't want to put the author's email address in this article, but you may find it in the Readme file that is part of the download.

V. More about TrIDNet — the GUI version

As stated earlier, the definitions for the GUI version are in a different format from the definitions for the command line version. The GUI definitions are in a large number of XML files, one for each file type — currently, 6,019 of them!

As with the CLI version, there's no installation needed — just unpack the ZIP file with the program (TrIDNet.exe) and copy the definitions (all of the XML files) into the same folder as the program file.

When running TrIDNet, here's the opening screen:


V. Conclusion

To come full circle to the group discussion that prompted this article, I fed to both TrID and TrIDNet a file that has 40 characters in the file name but no file extension. Here's the TrID command line with its result (via copy/paste from the command prompt window):

trid "d:\0tempd\40 character file name without extension"

TrID/32 - File Identifier v2.20 - (C) 2003-15 By M.Pontello

Definitions found:  6019


Collecting data from file: d:\0tempd\40 character file name without extension

100.0% (.PDF) Adobe Portable Document Format (5000/1)

Here's the TrID GUI result:


Both TrID and TrIDNet easily determined that it is a PDF file — and with 100% certainty. Of course, 100% certainty is not always the case, as shown in this real-life example of a file uploaded in a recent EE question. The file bumped into the 40-character file name limit and wound up with a .x file extension. Here are the TrID results on it:

TrID/32 - File Identifier v2.20 - (C) 2003-15 By M.Pontello

Definitions found:  6019


Collecting data from file: d:\0tempD\Time-Interval-Frequency-calculationv51.x

 51.3% (.XLSM) Excel Microsoft Office Open XML Format document (with Macro) (57500/1/12)

 45.0% (.XLSX) Excel Microsoft Office Open XML Format document (50500/1/11)

  3.5% (.ZIP) ZIP compressed archive (4000/1)

It is, in fact, a .XLSM file, as predicted by TrID, although with only 51.3% certainty. After changing the file type from .x to .xlsm, it loaded perfectly into Excel.

If you find this article to be helpful, please click the thumbs-up icon below. This lets me know what is valuable for EE members and provides direction for future articles. Thanks very much! Regards, Joe

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by:Joe Winograd, EE MVE 2015&2016
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Hi Bill,
Thanks for the kind words and the upvote — much appreciated! I like your "Dealing With Unknown Files and File Extensions" title — it's better than the one I chose. Regards, Joe
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by:Duncan Roe
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The Linux file command gets the file type right every time (file extensions are a Windows thing I guess)
Concerto Cloud for Software Providers & ISVs
Concerto Cloud for Software Providers & ISVs

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Learn how Concerto can help you.

The Rasberry PI is a low cost piece of hardware that you can have a lot of fun with through experimenting and building/working on projects like media players, running a low cost computer, build data loggers etc. - see: https://www.raspberrypi.org
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Thankyou Gerwin I've had my Rasp PI XBMC for about 5 years  and now understand  how to take it further than just a media device for mp4 on a SD card
XBMC is now Kodi.
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by:Gerwin Jansen, EE MVE
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Thanks and you're welcome :)

Why snapshot as backup-strategy?

When working with large to huge databases it is critical to take a backup of the database for disaster recovery and data failures that application either cannot recover or regenerate corrected data. For a database of such size it is vital that backup time is as short as possible to minimize application downtime/disruption due to backups. Regular backups can take several hours or more to complete for very large to huge databases.
The fastest way today to take a database backup is using the snapshot technology (sometimes called FlashCopy) either on a filesystem level or if the database has such technology implemented.

ZFS filesystem and snapshots

ZFS uses copy-on-write transactional object model allowing old data to be retained as new data is written and allowing snapshot versions of the filesystem to be maintained.
Here I will demonstrate how you can use the Solaris zfs filesystem (ZFS on FUSE) to backup MySQL/MariaDB database in as short time as possible.

Preparing the VM

For this demonstration I'm using Centos 6.5 64 bit with zfs-fuse in a VirtualBox VM with 1 Core (2.3 MHz AMD A10 ) and 1GB RAM, even though recommended minimum for zfs-fuse is 2 GB.
The VM disks (VDI format) are as follows
  • 20 GB disk with the Centos 6.5 system installed.
  • Three empty 5 GB disks that will be under the zfs filesystem.  
First thing is to make sure the SELINUX is disabled and reboot the VM after editing the config file as root :

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The purpose of this article is to demonstrate how we can upgrade Python from version 2.7.6 to Python 2.7.10 on the Linux Mint operating system. I am using an Oracle Virtual Box where I have installed Linux Mint operating system version 17.2. Once you download and install Linux Mint 17.2, Python software is installed by default. But the latest releases from Python are Python 2.7.10 and Python 3.4.3. I am using a 32 bit operating system as my host is 32 bit but you can still go ahead with 64 bit version which is preferred.

Log into the Mint operating system, and open terminal. Type "python" and hit enter or you can type "python --version" to check the existing version.
swadhin.ray-000036.pngTo download the latest version of Python, open https://www.python.org/downloads/ and click on "Download Python-2.7.10" as shown in below image.
swadhin.ray-000037.pngOpen the folder where the file is downloaded. In my system it's defaulted to "Downloads" folder.
swadhin.ray-000039.pngIf you open the tar file from the archive manager you can see the files that were downloaded.
swadhin.ray-000040.pngNow extract all the files under the same folder or you can choose a specific directory. Click on Extract button as shown below.
swadhin.ray-000041.pngswadhin.ray-000042.pngWait till the file get extracted.
swadhin.ray-000043.pngNow from the above image we can we can see that file is successfully extracted.
swadhin.ray-000044.pngNow open terminal and locate the extracted installation files.

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When I executed "./configure", you said it shouldn't have any errors, but mine did. When I did that, I got this output:

checking build system type... x86_64-unknown-linux-gnu
checking host system type... x86_64-unknown-linux-gnu
checking for --enable-universalsdk... no
checking for --with-universal-archs... 32-bit
checking MACHDEP... linux2
checking EXTRAPLATDIR... 
checking for --without-gcc... no
checking for gcc... gcc
checking whether the C compiler works... no
configure: error: in `/home/sara/Downloads/Python-2.7.10':
configure: error: C compiler cannot create executables
See `config.log' for more details

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What can I do to fix this?
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by:Swadhin Ray
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what is your OS version seems you are installing 64/bit on 32 .
The purpose of this article is to fix the unknown display problem in Linux Mint operating system. After installing the OS if you see Display monitor is not recognized then we can install "MESA" utilities to fix this problem or we can install additional drivers, for example Nvidia or ATI cards.
I am using a Minti OS on virtual machine, but when I tried to change the resolution I am not able to select anything.

Here are the steps to identify if the problem exist on your operating system.
swadhin.ray-000024.pngType Display on the search and click on the Display options as shown in above screen. Now if we try to select the drop down option from Resolution attribute then I am not able to select anything other than 640 x 480. It also has the same problem on other attributes like Refresh rate and Rotation. Finally when clicked on Detect monitors nothing happens: still shows the same problem.
swadhin.ray-000025.pngWe might see the "Unknow " message under Monitor attribute.
swadhin.ray-000026.pngTo fix this let's open terminal.
swadhin.ray-000027.pngType "sudo apt-get install mesa-utils" and provide your root password or if your existing user is a super user then use the same password.
swadhin.ray-000028.pngThis will install the mesa-utils package. Restart or reboot your OS.
swadhin.ray-000029.pngTo verify the installtion type " glxinfo | grep render " once your system is restarted:
swadhin.ray-000030.pngProvide the password to login.

swadhin.ray-000032.pngOnce restarted open terminal and type "glxinfo | grep render " and then type "glxgears".
swadhin.ray-000031.pngOnce done check the display again to verify if the issue is fixed or not.
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If you have more Mint articles in mind, I'll be a reader. This article actually gave me an idea for a similar problem on a non-Mint distro (though Mint is my personal standard).
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by:Swadhin Ray
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@tliotta : Thanks for your comments , Yes I do have few things in my mind will try to submit soon.
The purpose of this article is to show how we can create Linux Mint virtual machine using Oracle Virtual Box. To install Linux Mint we have to download the ISO file from its website i.e. http://www.linuxmint.com. Once you open the link you will see a download option at the right side of the page, go to the download page from the menu :

pic-2.pngYou can download 32 bit or 63 bit image and I am using 32 bit as my system is with 32 bit OS . I have downloaded and kept it on my specific directory where I can map to my Virtual Box while installing it.
Now open the VMBox and click on New to create virtual machine and map the ISO image to proceed with installing.  Once you set up all the necessary settings on memory space and disk space you will see the screen like below and then you can click on start button to start the installation.

Follow below steps shown with screen shot to start the virtual machine creation: 
2015-07-05-19-21-31-.jpgCick on New and proceed next :
2015-07-05-19-19-08-Oracle-VM-VirtualBoxGive any name to the virtual machine and select the type and version , click Next:
2015-07-05-19-19-26-.jpgSelect the memory size you want the VM to have -  I am using 1GB of RAM i.e. 1024 MB approximately. 

Click on Create button.
2015-07-05-19-20-52-.jpgClick Next. 

2015-07-05-19-21-00-Oracle-VM-VirtualBoxI am trying all default setting for installing the OS but you can choose as per your need. 
2015-07-05-19-21-18-.jpgHere we can set the size of the virtual hard drive . Once filled click on Create button. 

2015-07-05-19-21-31-.jpg Now set the ISO file which was downloaded from Linux Mint website. 
My Situation:
In 2013 I was asked by a friend of mine who is a web developer to help him set up a cloud based Linux Server that could be used for developing his ongoing web projects. I spent a fair amount of time looking at the various hosting companies, comparing costs, specs and so on. Fortunately I stumbled across DigitalOcean via a Twitter Advertisement and decided to give them ago - I haven't looked back.

Pricing and Spec:
The DigitalOcean price plans are highly competitive. I've previously had a VPS with 1&1 and was paying around $35.00 a month for a small server with 512MB, 1 Core Process and a 20GB Hard Drive. I was very happy to see that DigitalOcean was offering a near identical server for a mere $5.00 a month, the difference being that DigitalOcean provided an SSD Drive as an alternative to a standard Hard Drive.

More information on pricing can be found here: https://www.digitalocean.com/pricing/

DigitalOcean provide a Backup Service for their droplets charged per month at 20% of the cost of the virtual server. Snapshots however are provided free of charge but do require a reboot of the server.

For more information see here:

Deployment time:
When deploying a DigitalOcean Droplet you…
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by:Scott Fell, EE MVE
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For those people that understand the topic already and just need some direction, self help is easy to follow.  My point is Digital Ocean is good for developers that know what they are doing or just want to play around to learn.     Using DO for production should only be done when you are beyond knowing just enough to be dangerous and really understand what you are doing.

Reading through their help file on security https://www.digitalocean.com/community/tutorials/7-security-measures-to-protect-your-servers and note each section, "how difficult is it" and many of the items are more advanced.

For those just starting out, using a more traditional hosting service on shared hosting more than fits most needs and all of the infrastructure is done for you.

There have been a few long threads here on EE which is the best hosting service.  The threads are long and not much of a definitive answer because of personal opinion.  I tried many hosting companies over the past 10+ years and stuck with just a couple and learned about more from answering questions.  

My main point for commenting on your article is to point out Digital Ocean is for those developers that  want to use this for production will need to have a good understanding of servers, hosting and security.  It is a lot easier to spin up a droplet than it is to make sure you are set up properly.

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by:Gwyneth Michelle
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The only blip that DigitalOcean has is that it is not for beginners. You have to be a developer or at least have a technical background to deploy and manage a server on DO. In my opinion, the wiser thing to do would be to hire the services of Managed Cloud Hosting Providers like Cloudways and WPEngine. These services will not only take care of the technical aspects of deployment and management of your server, but also allow you to focus on the business aspect of your website. It is very convenient to set up a DO server using services like Cloudways and only requires a few minutes and a few clicks.

Source: https://www.cloudways.com/blog/host-wordpress-on-digitalocean/

In this article, I'll explain how to setup a Plex Media Server on a Redhat (Centos) 7 based NAS with screenshots to help those looking for assistance.

What is Plex?

If you aren't familiar with Plex, it’s a DLNA media server that offers the ability to access your own music, photos, and video. In addition, it also gives you the ability to access these on any of your devices, including PC, Playstation, Xbox, Android phone and tablet, iPhone, iPad, Windows Phone, Chromecast, Roku / Now TV, and so on. Wherever you are, whether that be at home, work, a friends house, or even on a plane (watch your data costs with this one tough, as even a transcoded video will gobble GB's) it will allow access. 

In addition to your media, the service offers the ability to aggregate your own media with artwork, recomendations, and playlists from the web or friends. Essentially it’s a Spotify+Flickr for your content. So, if you’ve got many GB’s of media and are after a handy tool to order and access it, not to mention eliminating the need to physically swap CD’s (just define a few play lists first and control the playback from a phone), this is the perfect tool to help you do so.

In addition to covering the basics, this crib sheet will help you access and map any additional content you have stored in OS X Time Machine sparse bundles, Microsoft .vhd, VMware .vmdk and Oracle .vdi or .iso disk image files on …
Recently, an awarded photographer, Selina De Maeyer, completed a photo shoot of a beautiful event in Antwerp, the Corpus Christi procession around the Saint James church. She took approximately 250 pictures with her two Nikon cameras, but when we went to publish the pictures in chronological order, we discovered that the time was not set consistently for her cameras.

With software, we were able to extract the .jpg files with the date and time once a picture has been shot. This allowed us to see that there were clearly two series of pictures, separated in time. Reordering so many pictures manually was not an option. So we decided to write a little script to correct the date and time on the set that was wrong.

The first item to address was the origination of the camera for each picture.  There is an open source suite called ImageMagick that provides a program called identify. Identify is able to list information for each picture. All the programs we invoke below are run from the command line interface - the shell. If you never heard about the shell, I am sorry to tell you: do not read further, this article will bore you. but if you are familiar, you will know that grep will filter the lines containing a certain pattern from the results of the previous command.

Information returned by identify
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by:Pierre François
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Dear Brad,

Thanks for fixing the typos.

You said:
A volunteer Page Editor may engage you on the content to improve your article further.

I would be happy to know what I have to do to get this done.

Thanks in advance.
Linux containers are abbreviated as LXC. They are the forms of lightweight operating system level virtualization for computers that are running Linux. Containers do not provide the virtual machine but provide a virtual environment where the containers share the same operating system as the host.

This is accomplished with some key features:
  1. Chroot
  2. Namespaces
  3. Cgroups
These features create an environment that allowd the running of multiple containers concurrently on the same host. The idea behind a container is to implement a technology that would enable separate processes to run together without the requirement of any other operating system or hypervisor applications. Containers share the same kernel with anything else that is running on it, but they can have constraints on the usage of resources like CPU, memory, hard drive or I/O. This Linux feature has been out in the version 2.6.24 of the operating system.

Concept behind the Implementation of Linux Containers

Containers are considered a better alternative to the traditional hypervisors like ESXi, Xen and so on. The hypervisor is an emulated hardware for the virtual machine and on the top of these virtual machines. Users used to have memory and applications. With the help of a hypervisor, you can have multiple virtual machines on a physical server. It is effectively like virtualizing a system at the hardware level.

If you want to have multiple …

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Virtualization Lover

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nice article...yes definitely replacement for esx hyper visor.
What does it mean to be "Always On"?
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Virtual Machine and Containers are both techniques for virtualization and in many scenario either can be used. Though Virtual Machine and Container are similar in many ways, they both have there own space and can coexist in the same ecosystem. 

Virtual Machines utilize a concept called “Virtualization” to utilize resources on a machine to create one or virtual machines running its own operating systems. The primary machine is often referred as “Host” and virtual machines as “Guest”. These virtual machines are created by the virtualization software like VirtualBox or Vmware by intercepting access to certain hardware components and certain features from the host machine.

Containers utilize operating-system-level virtualization method. It requires OS kernel support which allows multiple isolated user space instances sharing host operating system resources. These instances are often called containers. LXC provides container support for Linux and very recently Microsoft announces container support for Windows ecosystem via Windows Server Containers. Docker is an open platform to build, ship, and run distributed applications as containers.
Though Virtual Machine and Containers are both virtualization …

From Coral's  "So You Want To Play With Computers" Series

A bit of background first, so this story will make a little sense.

One day, probably because he needed a good laugh, Finagle hooked me up with a church to upgrade/run their Media Booth. {Yeah, I know. I've been to "Hell and back" so many times, I already have my spot picked out and homesteaded}.
Anyhow, getting time to work on their system is hard to do, so I've been dual booting to a clone of their hard drive, so I can check the music, fix/add lyrics, and set up the music schedules, at my place. Then copy the schedules for a couple of weeks to a USB stick to take in with me, and copy to their computer.
But lately they have been throwing new music at me, and booting back and forth between Vista (nic is blocked) and W7, to go online to chase down lyrics, is getting to be a pita.

So I thought I would move Vista to a VM, then I could just toggle between them. Which brings me to what follows:

After firing up my Googlefu, and doing some research, I had a few points I wanted clarified, so I posted a Q on EE, which Finagle promptly kept the VM Gurus from posting in. Looks like I'm on my own.
That's alright. I can do this. After all, I'm a self taught computer geek. I've been mucking with computers for over 25 years. And I recently took a ComTIA  A+  Cram Course, and set the new high A+ test score for that class. As a bonus, it kind of irritated the college boys …
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added screenshot of Vista running in MS Virtual PC.    ; )
Automating work can be done on Linux / Unix by creating what is called a cronjob that is periodically running a program or script (job) on a schedule you specify. Jobs are specified in a crontab (file) and are run by the cron daemon process.

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by:Yashwant Vishwakarma
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Good One
Very useful for Linux sysadmins and Oracle DBAs.
Voted Good article :)

Thanks for sharing it

Yashwant Vishwakarma
Steganography is the hiding of a secret message within an ordinary message and the extraction of it at its destination.  Steganography takes cryptography a step farther by hiding an encrypted message so that no one suspects its exists.  Ideally, anyone scanning your data will fail to know it contains encrypted data.
Check the TechTarget Link for more information.  In today's society it is imperative for individual(s) and companies to keep information secure and out of intruders hands.  Placing more obstacles in their way would deter an intruder from obtaining important information.  I will explain in this article one steganography tool in Ubuntu that can assist you in hiding personal information.

This article will show you how to embed a text file in  a picture.  Outguess relies on data specific handlers that will extract redundant bits and write them back after modification.  Currently only the PPM, PNM, and JPEG image formats are supported; per the man pages.

*Note: found that it does not work with JPEG extension so you would have to convert it to a JPG extension instead.

First you would need a image file and download it to a location.

Let us check to make sure it is not install already, in our case it is not.

Open the terminal session

Ctrl + Alt+t

Now type:
dpkg --get-selections outguess

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If is not install now we are going to install the application

sudo apt-get install outguess

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Checking the install of Outguess and Installing it.
If you are at *nix system, whether you are System administrator, common user, programmer or whoever; you will surely need to find file using different criteria. For that *nix system has very powerful and efficient command called “find”.

The find command is a powerful *nix utility that allows the user to find files located in the file system through various criteria such as the file name, owner, group, size, inodes, when file was last accessed, when the file status was last changed, the file's permissions, even using regular expression pattern etc.

I will try to cover maximum usage of commands that you are gonna need for any such operations. I hope after reading those examples one will easily use find command for one's problem.

Syntax for find command:
find where-to-look criteria what-to-do 

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Instead of explaining each options and then showing you its uses with examples, better to see the use of all options while going through different examples based on various requirements.

1.       Find a file "alien.coders" that exists somewhere in the file system
$ find / -name alien.coders -print 

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If the file is found the path to the file will be printed as output. On most platforms the -print is optional, however, on some *NIX systems nothing will be printed without using print. If you don’t provide any arguments, find searches recursively through all the directories.

2.Find a file without searching network or mounted file systems
$ find / -name alien.coders -print -xdev 

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I am writing this from an Ubuntu (and likely Debian) perspective, but most of it translates to RPM based distributions. This deployment is tested and running on Ubuntu 12.04 using 2 cores and 3gb of RAM. Disk space requirements vary based on how many servers you have shipping logs to it; Graylog2 keeps the last 60 days of data and purges every 30 minutes by default, but you can adjust the storage settings if you have other requirements.

The first thing I would like to share about this set up is: I start from the Binaries or sources for everything except MongoDB; there are PPA's with the other parts in them but I had nothing but problems with those.

The second thing is that this is not a complete copy/paste article; I will lead you but assume you know your system well enough to actually complete some of the steps I provide

--The good bits--
So you have all these verbose, helpful logs on all of your servers, but you are getting tired of logging into each server to trace traffic through your stack.

An easy solution is to ship your logs over to another server then you only have to log into one server to look at your logs but now you are using up valuable system resources syncing them on a schedule, and you will find yourself waiting for the newest ones to show up.

You are close to a working solution... but now you need a notification when a condition occurs in those logs. There are a lot of options out there for centralizing and …
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by:Eric AKA Netminder
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Linux is a UNIX-like open source operating system with hundreds of distinct distributions, including: Fedora, openSUSE, Ubuntu, Debian, Slackware, Gentoo, CentOS, and Arch Linux. Linux is generally associated with web and database servers, but has become popular in many niche industries and applications.

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