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WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
09/06/2010 - 19:03

When you logging into a Linux box using ssh, the Linux where you are logging from will ask you to validate the authenticity of the key presented by that host.

Once you answer yes, that key will be stored. Future logging attempts to that same server will check they key against what is stored in the file:

~/.ssh/known_hosts

If they do not match, may mean that someone is in the middle trying to capture your password, so be careful when you see some alert like this:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
5c:0b:18:56:b6:cd:12:10:32:cd:1d:a2:9a:cd:e5:1c.
Please contact your system administrator.
Add correct host key in /home/user/.ssh/known_hosts to get rid of this message.
Offending key in /home/user/.ssh/known_hosts:3
RSA host key for server.mydomain.com has changed and you have requested strict checking.
Host key verification failed.
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
09/06/2010 - 19:03

When you logging into a Linux box using ssh, the Linux where you are logging from will ask you to validate the authenticity of the key presented by that host.

Once you answer yes, that key will be stored. Future logging attempts to that same server will check they key against what is stored in the file:

~/.ssh/known_hosts

If they do not match, may mean that someone is in the middle trying to capture your password, so be careful when you see some alert like this:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
5c:0b:18:56:b6:cd:12:10:32:cd:1d:a2:9a:cd:e5:1c.
Please contact your system administrator.
Add correct host key in /home/user/.ssh/known_hosts to get rid of this message.
Offending key in /home/user/.ssh/known_hosts:3
RSA host key for server.mydomain.com has changed and you have requested strict checking.
Host key verification failed.
Improve speed of your Linux by using preload
09/03/2010 - 17:55

With preload, you can speed up your Computer, but, only if it is running Linux Operating System.

According to Wikipedia:

"preload is a Free Linux program written by Behdad Esfahbod which runs as a daemon and records statistics about usage of programs using Markov chains; files of more frequently-used programs are, during a computer's spare time, loaded into memory. This results in faster application startup times as less data needs to be fetched from disk. preload is often paired with prelink."

It is really easy to install, as it is included in all major package manager includes it.

/dev/xdx does not have any corresponding BIOS drive Reinstall Grub2
09/02/2010 - 15:39

Today in my busiest hour, after a fool action I lost grub. And as smart as I am, I rebooted the PC, so I got locked out of it.

Well, time to boot with a live CD and reinstall Grub. This is what I've done.

sudo mount /dev/hdb3 /mnt

That will mount my root partition in the mnt directory of the Live CD session.

sudo mount /dev/hdb4 /mnt/boot

UUID on Linux fstab file
09/02/2010 - 16:37

UUID stands for Universally Unique IDentifier and it is used in Linux to identify disk in the /etc/fstab file.

This way, the order of the disk in the motherboard can be changed, not affecting the mount point they will have.

As can be seen, it is a good idea to have fstab using UUID instead of the /dev/xdx way to identify the disks.

Share a single file from your Linux. To any device with a web browser
09/01/2010 - 23:44

I have been in the situation of having to share a file with someone in the same room with me, and I had to send it by email. Just because you do not have configured both devices (PCs, Laptops, Smart Phones, etc) to share files in a network, does not mean you can not share files.

Share a single file from your Linux. To any device with a web browser
09/01/2010 - 23:44

I have been in the situation of having to share a file with someone in the same room with me, and I had to send it by email. Just because you do not have configured both devices (PCs, Laptops, Smart Phones, etc) to share files in a network, does not mean you can not share files.

Share a single file from your Linux. To any device with a web browser
09/01/2010 - 23:44

I have been in the situation of having to share a file with someone in the same room with me, and I had to send it by email. Just because you do not have configured both devices (PCs, Laptops, Smart Phones, etc) to share files in a network, does not mean you can not share files.

How to read CHM files on Linux, convert it to PDF
08/31/2010 - 22:18

CHM files are a html help files used by microsoft, and others to provide help files

From Wikipedia:

"Microsoft Compiled HTML Help is a proprietary format for online help files, developed by Microsoft and first released in 1997 as a successor to the Microsoft WinHelp format. It was first introduced with the release of Windows 98, and is still supported and distributed through Windows XP, Vista and Windows 7 platforms"

How to read CHM files on Linux, convert it to PDF
08/31/2010 - 22:18

CHM files are a html help files used by microsoft, and others to provide help files

From Wikipedia:

"Microsoft Compiled HTML Help is a proprietary format for online help files, developed by Microsoft and first released in 1997 as a successor to the Microsoft WinHelp format. It was first introduced with the release of Windows 98, and is still supported and distributed through Windows XP, Vista and Windows 7 platforms"