Category Archives: How To

How To documents with practical advices and detailed description for various Information Technology tasks.
The articles are mainly focused on Small and Medium Businisses but they can easily apply to large businisses as well.

Snagless RJ45 connectors – How To Make Network Cables Snagless

Patch Panel

Snagless RJ45 Connectors – the Odd Request

Snagless RJ45 connectors are that odd request that my department makes from time to time. Why do you need RJ45 connectors anyway, it’s the invariable answer from supervisors, and the typical reminder: “You have all sorts of patchcords, all dimensions…” Well, first of all, we sysadmins never have all the patchcords dimensions available. The IT racks should be something that should be kept as tidy as possible, and one way is to have custom length of the patchcords.

Depending on your infrastructure, you might want or might not want to use handmade patchcords in your racks; however, in many cases this is totally acceptable. You can probably make a Cat 5 patchcord, but you won’t be able to make a Cat 6 one. In other words your hand made patchcords will be able to run at Gigabit speeds, but not at 10 Gigabit speeds, even with the proper connectors and cables. Having said that, most of the equipment in a business server room is connected into a Gigabit switch or at lower speeds, so this would not be a problem.

Custom Patchcords – Always Broken Lokcing Tabs

The major problem with all the handmade Ethernet patchcords and cables is that the locking tab is breaking. I probably don’t have to explain why broken tabs are bad; they will not be secured into the equipment’s jack, resulting in intermittent data loss, or even disconnection.

There are two reasons for the locking tabs breaking so often. Firstly, the little locking tab is very fragile, and we can’t change that, it is fragile to keep the costs down. The other reason is the design, the locking tab sticks out, and it is very easy to get snagged and broken off. All store-bought cables come with a snagless boot; it’s the standard these days. All the cables with broken locking tabs don’t have the boots, because they are terminated in place, by either a datacom tech, or an admin.

These plugs from Panduit are the best snagless RJ45 connectors.

The connectors are meant for patch cords, and they are rated as providing Category 5e performance.

The patented tangle-free plug latch prevents snags, hence breaking.

They are easy release, unlike some snagless boots, and they save time on frequent moves, adds, and changes.

The design facilitates easy insertion and termination of wires

What Is the Solution for Broken RJ45 Connectors

One of the solutions to fix the snagging network cables is to install a "snagless" boot over the cable, before crimping the connector. After crimping, just push the boot over the connector and the boot will protect the little tab.

My preferred way to fix this is to use snagless RJ45 connectors, and a boot. This ensures the plug will not break ever, unless you purposely do it. You can also use just the snagless connectors, they are very good, and I do it very often, but if I have both the snagless connectors and the snagless boots, I will use both for optimization. The snagless plugs are slightly more expensive than the regular ones, but when you draw the line, and consider the troubleshooting needed on the long term, and the fact that sooner or later those RJ45 connectors will break and will need to be replaced, the additional cost is worth paying.

Like I already mentioned before, with the low prices for commercial made patchcords, and the quality ensured by a machine made ethernet cable, there is no need to make your own, it's just not practical.

This cables are made in a commercial facility, they are tested, and they come in a variety of lengths, just choose the one that is right for you. You can even get  to choose the color, so you can color code your patch panel connections, so everything looks tidy, and easy to follow.

How to Copy Large Files over VPN or Other Unreliable Network Connections

Network Error While Copying

Large file transfer over VPN is a problem for many companies for a few reasons, transfer is unreliable, VPN traffic kills the Internet connection, and it is unproductive. This article will show you how to copy large files over VPN or other unreliable network connections, and some of the best software to deal with this, and best practices to deal with large file transfer, and how to ensure file integrity. These are, in my experience, the best way to do it. You have to evaluate yourself, if they work in your environment, and test a lot.

When copying files over VPN, there are a few problems that need to be addressed:

  • file transfer can be easily interrupted,
  • over saturating the VPN connection,
  • redirecting all the available traffic to the VPN connection
  • ensuring the transferred file is undamaged

Let’s talk a bit about all of these, why they are important, and how they affect the success of your file copy. This will give you, hopefully, a clearer image of the process.

Network Interruption – File Transfer Failed

When we talk about large file transfers, an interruption after a few hours of transfer is not a good thing, and if you take in consideration the time spent, and to only realize you have to do it again because the transfer failed. There are many reasons for the network to interrupt, and even a second is enough to corrupt your file. VPN is prone to network interruptions with large files, because it saturates the Internet bandwidth, and when other VPN clients try to use the VPN tunnel, the file transfer will be interrupted.
The fix for this is some kind of transfer resuming at both the server level and the client level. A few client-server protocols that support file resuming are: SMB, FTP, HTTP, rsync.

The easiest way to implement file transfer resuming in a corporate environment is through SMB and robocopy. Robocopy has a feature to copy in restartable network mode, so if the network goes down, it will automatically resume the transfer from where it left. The robocopy option to copy in restartable mode is /z as with the regular copy command.

robocopy /mir /z  X:\source-folder\ \\RemoteServer\RemoteFolder

Rsync has also a resume option, and it works great, but you have to make sure you use the network filesystem and not a locally mounted network directory. The command to transfer will be like this:

rsync -aP juser@server:/RemoteServer/Directory /Home/Local-Directory

Filezilla has an option to resume files after interruption, but there is a timeout setup by default. Make sure you set the timeout to 0, so that you can recover even after a few hours with no connection between server and client. Note, that this is not a good option if you have many clients, since it will keep open connections indefinitely.

Time Out Config for Resuming

Apache has also an option to allow file resuming, which is enabled by default. The disadvantage with Apache is that, by default it doesn’t support file upload. If you are determined to use Apache for this though, there are some ways to do it, you can start your research here: File Upload plugin for Apache

Over Saturation of the VPN Connection

The VPN connection is there for many users, don’t think that your file is the most important think in the world. If you take all of the bandwidth for your file transfer, other users might not perform daily important tasks.

The over saturation of the VPN connection can be avoided by implementing bandwidth limiting at the software level.

You can do that with SMB by using robocopy, at the client level. The command will look like this:

robocopy /mir /IPG:250  X:\source-folder\ \\RemoteServer\RemoteFolder

The IPG parameter is the one that controls the bandwidth; it’s the acronym for Inter Packet Gap, and with an IPG of 250, the transfer rate on a 100 MBps network is around 12.7 MBps. The lower the IPG, the higher the bandwidth saturation. The transfer rate will be different for different network speeds.

With FTP is going to be at the server level, it’s very simple if you use Filezilla FTP server. Just restrict the bandwidth to a safe limit, (note that there is no restriction in the picture).

FileZilla configuration

Apache uses mod_ratelimit to control the bandwidth of its clients. For more information about that take a look at this page:
http://httpd.apache.org/docs/trunk/mod/mod_ratelimit.html

Rsync can also limit the bandwidth at the client level, and the option will be “–bwlimit”. A command to synchronize two folders with rsync, throttling the bandwidth, would look like this:

rsync –bwlimit=3000 /local/folder user@RemoteHost:/remote/backup/folder/

The 3000 means 3000 kbps. IMPORTANT, if you use

Control VPN Traffic

It looks like a simple decision to allow all the traffic possible through the VPN, most companies will determine that VPN traffic has the highest priority. However, in real life there are many non VPN applications that are run from the Internet, and are critical for a business. Booking a flight ticket, using a hosted web application, getting your emails from a hosted email server, etc… So it might make sense to control the maximum bandwidth used by the VPN, and this is especially needed in environments where large file transfers over VPN are very common. The best way to control this is through firewall policies to limit the bandwidth for the VPN destination. On some devices, like the Fortigate firewalls I am using, this is called traffic shaping.  On other devices might be named differently.

File Integrity Verification

There is a mechanism for checking the file integrity with robocopy and rsync.

The perfect tool to make sure your file is identical with the remote one is to check with md5. On Linux this is a package that comes by default in many distributions, on Windows you can use WinMD5, that you can download it here: WinMD5

MD5 checksum

How to Recover Deleted Pictures or Files – Data Recovery Tools and Techniques

Trashed hard driveHelp, I lost My Pictures!

If you lost or accidentally deleted your pictures and files, there are still great chances to recover them. As a computer geek, (I do this as a profession), I had to recover file many times. In the vast majority of time the files are recoverable, and in about 30 percent of the cases the retrieval is instant.

The key to a successful retrieval of your pictures and files is to act as soon as you discovered you lost the files, be it because an accidental deletion, or computer problems. I will explain this later in the document.

This tutorial is created for Windows computers, and it assumes you have a minimum knowledge of operating in a Windows Operating System. If you don’t know how to operate in a Windows environment, your best bet is to go to a local computer repair shop.

How To Recover Deleted Pictures or Files?

The Computer IS Fine, But My Files Are Gone

If the computer is fine and it doesn’t behave erratically, most likely you accidentally deleted your files. The first step in this case is to check in the Recycle Bin, but I bet you already did this. If you didn’t do it now. Look for pictures or maybe just a folder, If you accidentally deleted the whole folder, you won’t see the files or the pictures in the Recycle Bin, you will have to look for the folder that contains the files. This is particularly difficult if your Recycle Bin hasn’t been emptied in a while, and you have to search through thousands of files.

How to Recover Deleted Files from Recycle Bin – Advanced Tutorial

Sorting the Items In the Recycling Bin

If your Recycle Bin is empty, or you have few items, you can skip this.
To make it easier right click in the “Recycle Bin” folder and choose sort by “Date deleted”.
If the deletion was made long time ago this doesn’t make sense, and you would probably need to sort by type. Sort by type is not available by default on the Recycle bin, so you have to activate it. Right click in the Recycle Bin folder, select “Sort By”, and the choose “More”. Scroll down on the list and check the box for “Type”. Now the “Sort by type” is available from the contextual menu. When you sort by type all the folders are displayed grouped so it’s easier to find your pictures folder if it’s in the recycle bin.

httpv://www.youtube.com/watch?v=10ERJcqMWIg

Recover Deleted Pictures or Files Using “Previous Versions”
Recovering with Windows 7 Previous Versions
If your operating system is not Windows 7, you can skip this paragraph, this feature is only available on Windows 7.
If your files are located on the System drive, usually the C: drive, “Previous Version” is enabled by default. “Previous Version” it’s a feature that allows the system to store on a hidden portion of the drive, files and system settings. The files are automatically copied on the hidden folder, and stored for a limited numbers of days. When a file is modified, or deleted, the old version is stored automatically. Let’s say you deleted some pictures in the “Pictures” folder. Go to “My Computer” => C: => Users => USERNAME . Search for the “My Pictures” folder and right click on the folder. From the contextual menu select “Restore Previous Versions”. A list with snapshots of the folder will be presented. Select a previous version that you think contains the deleted files. If you accidentally deleted the files today at 11:00 AM, any snapshot previous to this date and time would contain the deleted files. Neat huh? The trick here is to act as soon as you deleted the files. The longer you wait the bigger the chances to get the good snapshot deleted are. The snapshots are deleted on a regular basis by the system, so if you wait too long, the files will be deleted.

httpv://www.youtube.com/watch?v=jnPI9p9rNkY

Lexar Media IR437 Image Rescue Software (Retail Package)

Recover your lost or deleted files with this easy to use software. The software will scan raw data on you memory card, and it will find your lost pictures.
Lexar Image Rescue has an intuitive and easy to use interface, and will scan the mass storage device, (sd cards, USB drives), for deleted image files or after reformatting your SD card. Additionally, the newest version of the software, can recover, not only image files, but many other popular document types.

This is probably one of the easiest, and most effective image recovery software.

Data Recovery Tools

Recovering Deleted Files with Data Recovery Tools

If the two methods described above didn’t work for you, that means the data has been erased from the disk. The good news is that operating systems do not really delete the files when you delete them, the OS only deletes the record from the index, so from the OS’s perspective the file doesn’t exist anymore. This is where the data recovery software comes in handy. The data recovery software scans the drive for possible files that are deleted from the index, and reassembles them for you.

As with any other recovery method the key is to act as soon as possible. The more you use your drive after the deletion, the less chances you have for a full recovery. This happens because Windows treats the portion occupied by your lost files as empty, and will start to write new data over your deleted files. The more you use the drive the more deleted data is overwritten.

The data recovery software is usually an intuitive program that can be installed on the computer, or can generate a bootable media. The purpose of the bootable media is to avoid the use of the hard drive, to maximize the chances of a full recovery, or sometimes provide an environment for un-bootable systems.
The process of recovering data with tools is very easy, and it is somewhat similar for all software, but not all data recovery programs are the same. The scanning algorithm, the reading approach are things that can make or break a recovery utility.

A few general rules for all recovery software:
To avoid further data corruption, mount the corrupted drive on another intact system. You can do this in a couple of ways:
Install the software on a separate system and attach the drive with a USB enclosure or adapter.
Create the recovery media on another computer and boot the computer with the bad drive from the bootable recovery media
Only start doing the job when you have enough time to dedicate. If you start and stop, and then start again you risk to lose more data.

How Can I Recover My Pictures After Formatting the SD Card

Pictures Recovery after Deletion or Formatting with Recovery Software

If you accidentally deleted your photos on the SD card there is no Recycle Bin for the SD card, so there is no easy way to recover them. Also it happens quite often to format your SD card and to realize that you didn’t save the pictures yet. What do we do in cases like this?
Fortunately, there is software that makes the recovery for cases like this a breeze. One of the easiest to use programs is “Sandisk RescuePro Recovery Software”.

Sandisk RescuePro Recovery Software, V3.3 Disk

It works on and card not just on Sandisk cards. It is really easy to use, and in most of the cases it is able to recover your pictures. One thing about this is that you need to wait the code for the software for a few days, but is worth. The software is actually an annual subscription, but it is very affordable.

Remember, if you deleted the pics on your card, or formatted the card, you need to stop using it immediately to insure a good recovery rate.

Recover Files from A Defective Computer

How To Recover Pictures and Files from A Defective Computer

Your computer might be defective and it won’t start. What to do in this case? First you need to assess the state of the computer and why the computer won’t start. Depending on this, you might be able to recover your files or not. In the next paragraphs I will give you tips to know what is wrong with your computer, and what to for each case.

  • If your computer boots and you can get on your Windows account, then probably the files were accidentally deleted.
  • If your computer passes the initial boot sequence but stops when loading Windows, it is the operating system that is corrupted. A re-installation could fix it, or a boot rescue CD could also fix the OS. Sometimes this could be due to bad computer RAM memory.
  • If your computer doesn’t pass the initial black screen booting sequence, something more serious could have happened, such as a defective hdd, or some other hardware problem.
  • If the computer doesn’t do anything, it is also a hardware problem. You can tackle this with a local computer shop, or proceed to moving your drive on another computer.
  • If the computer starts but it doesn’t recognizes your hard-drive, then you cannot rescue your files anymore. Actually there are data recovery services, that will disassemble your drive, and will read the data on the platters with special equipment. These are special services and are very expensive. Most of us prefer to lose the family pictures than to pay for these services.

What To Do If The Computer Won’t Boot

My Computer Won’t Boot, I Need My Pictures And Files

There are many reasons why your computer won’t boot. If you think your computer is not worth investing too much work to revive it, then the easiest way to recover your files is to take out the old hard-drive, mount it on a USB enclosure, and read it through USB on a good computer. You will be able to read your old files without any problems. This method assumes your hard-drive is not defective.For the case that Windows won’t boot because of a file-system corruption, or other Windows corruption problems, there is the Recovery Boot Disk that will allow you to boot your computer and fix a wide range of problems.

If the hard disk is the one that caused your computer to not boot, you still have good chances to recover your files, but in many cases you need a data recovery software like Data Rescue PC 3, to scan for files on the corrupted disk.

If the computer warns you before booting that there is a problem with the disk drive, you need to stop immediately using the drive if you want to maximize your chances of recovering the data. If your drive is making clicking noises, you also need to stop using it. Sometimes a hard-disk will have just enough life for a last run, so after recovery it will die.
The next step is to acquire data recovery software and install it on a good computer, and buy a USB enclosure and use it to mount the drive from the defective computer. Now connect the hard-drive to recover on the good computer and start the recovery.

Data Loss Prevention

What can I do to prevent data corruption or data loss?

  • Enable in BIOS and on the hard-drive S.M.A.R.T. This is a software utility embedded on the hard-drive that will detect when too many error corrections are occurring. Whenever this happens it means that you drive is near an imminent failure and you should backup/replace it.
  • If a message of a hard drive error appears, stop using your computer until you change the drive. You can use the computer to make a backup of your data onto another drive.
  • Check old backup tapes and copy them onto new tapes, using a temporary restore. This should happen each 10 years or more.
  • Check the data stored on CD’s and DVD’s, and recopy that media regularly. Not all CD and DVD media are equal. The factory-recorded media is the longest lasting. The media burned at home or on a computer CD-ROM unit can last between 1 to 10 years or more. So it is wise to rerecord it after a few years if you bought good quality media, or after one year if it’s on cheap media.
  • Buy an antivirus and keep it up to date.