I have a few administrative accounts that I do not want accessible via a password, only ssh keys. There are two ways to disable password authentication on a linux system:
1) Lock the password if using linux user accts, ldap, or whatever your using.
2) Tell ssh to not allow authentication with a password in your sshd_config file.
For method 1:
# passwd –lock username
Note this won’t lock the user out of the account but rather lock their password so they cannot use one.
As an admin, you love to automate things. Lets say other users you have setup on your system run certain applications that may need to run in their own little shell. Instead of having to log into the server as that user (su’ing into a user and trying to create screen sessions doesn’t work very well) and making more work for yourself, you can actually (as root) start a screen session for the other user and define a command to run in the virtual terminal.
I have recently ventured into using screen (a virtual terminal in linux) in a multiuser setting. This is necessary when users need to collaborate on a project or for server which run their console in a “not” daemon sort of way.
Basically, you can setup a virtual terminal and allow other people to access it. You can even be in the same shell as someone else which is extremely useful for helping other configure settings or program.
Less Hair
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The Mayor of Sterling Hts. and I @ my Eagle Scout Ceremony
My name is Mario Loria and I am currently a student at Michigan Tech University. I am majoring in Computer Networking and System Administration as well as pursuing a minor in Economics.
I have been working with computers for over 10 years and specialize in the fixing, building, and networking of computing systems.
So I have for a long time had a backup script that copies the essential files to a directory in /home, and then tars, gzips, and encrypts /home so I can save all my home dirs + important things living on the root filesystem. But the way I used to do it before was really stupid and involved creating a tar, gzipping it, and then encrypting that and making another file of it…basically a bunch of unnecessary read and writes happening on the hard disk.
For years I have stayed away from ever wanting to mess with grub hoping that with each no os re-install, everything would just work. However, I recently had to face the facts and realize that there is no way for things to just work especially when adding a new 500GB hard drive with windows into the mix. The basic idea of just editing your menu entries just does not seem to be cutting it for me.
So you want to host your website in RAM? It will certainly help if you a database or very large flat files and I recently decided our sqlite database and the tons of images we have should probably be hosted in RAM since I certainly have plenty of it (24GB’s).
On linux, you can use pretty much one command to do this by using tmpfs which will manage the memory usage for you based on what files you decide to put in ram.
IPTables provides you a way to make your own chains. A chain in iptables is a section of rules that iptables will run through whenever you specify. The main chain for input is the INPUT chain. I recently needed to start blacklisting ip addresses trying to attack us and it was necessary to create a new chain where I could store those ip’s instead of throwing them on the default INPUT chain which would be messy and stupid.
EDIT: Meme101 now runs from http://meme101.tty0.in/. It is no longer being updated and is kind of stagnant/dead.:(
Some close friends and I have created a new site that contains memes pertaining to a bunch of different colleges and universities. If you have some free time or feel like wasting time, Please check it out.
There’s anonymous upload too!
I use scp quite a bit. But I never had to use it with directory paths involving spaces until now (for some odd reason, I must be good at naming things as simple as possible, a good habit by the way).
In order to use spaces, as per this article, it is necessary to add three back slashes and the space.
At least that is the easiest way. Take a look at the linked article for more about it.