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Questions tagged [linux]

Linux is the generic term for a UNIX-like open source operating system based on the Linux kernel.

GNU/Linux is a UNIX-like Open Source operating system. Linus Torvalds originally wrote the Linux kernel with contributions from others on the MINIX usenet board. Since then, Linux had thousands of developers, both paid by companies and volunteers. The main system tools and libraries for GNU/Linux are sourced from the GNU Project, hence the nomenclature GNU/Linux (GNU Toolchain over Linux Kernel). The Linux kernel is licensed under the GPL v2 license.

There are many different Linux Distributions (sometimes shortened to distro), which consist of software applications packaged and provided with the Linux kernel, being Slackware the oldest active distro and Debian, Red Hat and CentOS among the most used on Internet servers¹.

The Linux kernel is commonly run on servers but is highly portable and is used in a variety of applications, from wireless routers and cell phones to clusters and super computers with thousands of nodes and processors.

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Explanation of nodev and nosuid in fstab

I see those two options constantly suggested on the web when someone describes how to mount a tmpfs or ramfs. Often also with noexec but I'm specifically interested in nodev and nosuid. I basically hate just blindly repeating what somebody…
Ivan Kovacevic
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What solutions exist to allow the use of revision control for server configuration files?

In an environment with multiple system administrators, I see a few advantages to adding the server config files into a revision control system. Most notable are the ability to track changes, who made them, and of course being able to roll back to…
Dave K
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Amazon Linux vs. Ubuntu for Amazon EC2

I'm setting up my first website on Amazon EC2, and I'm trying to decide which distro to use. I've used Redhat and CentOS in the past, but I have no bias towards any system, I just want to use whatever is best (I also have had partially-managed…
James Simpson
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How do I redirect subdomains to a different port on the same server?

I have some subdomains I want to redirect to specific ports on the same server. Say I have dev.mydomain.com I want dev.mydomain.com to transparently redirect to mydomain.com:8080 and I want to preserve the original sub-domain name the url of the…
user35861
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zcat/gzcat works in linux, not on osx. general linux/osx compatibility

First the specific problem: In linux, I use zcat to list a .zip file. In osx, zcat seems to automatically append .Z to the file name. Various people suggest replacing zcat with gzcat; however, gzcat complains that the file is not in gzip format!…
user23398
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Practical maximum open file descriptors (ulimit -n) for a high volume system

We recently began load testing our application and noticed that it ran out of file descriptors after about 24 hours. We are running RHEL 5 on a Dell 1955: CPU: 2 x Dual Core 2.66GHz 4MB 5150 / 1333FSB RAM: 8GB RAM HDD: 2 x 160GB 2.5" SATA Hard…
Kevin
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How can I list my open ports on Debian?

What is the command to display a list of open ports on a Debian server? I tried netstat -a | egrep 'Proto|LISTEN' but I would like something more specific that actually lists the port number.
leonel
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protocol version mismatch -- is your shell clean?

When following the instructions to do rsync backups given here: http://troy.jdmz.net/rsync/index.html I get the error "protocol version mismatch -- is your shell clean?" I read somewhere that I needed to silence the prompt (PS1="") and motd…
rfreytag
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Command line program to test DHCP service

Is there a simple ping-like command to test whether a DHCP service is running on a network? ...on Linux
pufferfish
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How to remove invalid characters from filenames?

I have files with invalid characters like these 009_-_�%86ndringshåndtering.html It is a Æ where something have gone wrong in the filename. Is there a way to just remove all invalid characters? or could tr be used somehow? echo…
Sandra
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Hundreds of failed ssh logins

Every night I get hundreds, sometimes thousands, of failed ssh logins on my RedHat 4 server. For firewall reasons from remote sites, I need to run on the standard port. Is there anything I should be doing to block this. I notice that many come from…
MattMcKnight
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Transfer 15TB of tiny files

I'm archiving data from one server to another. Initially I started a rsync job. It took 2 weeks for it to build the file list just for 5 TB of data and another week to transfer 1 TB of data. Then I had to kill the job as we need some down time on…
lbanz
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Running Cron every 2 hours

I have the cron job as shown below, and wanted it to run every 2 hours, but it keeps running every 2 minutes. Can someone tell me where I'm going wrong? * */2 * * * /path-to-script
Helen
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What does "debconf: delaying package configuration, since apt-utils is not installed" mean?

I have just installed Debian and I was just installing some packages using apt-get instal when I saw this message: debconf: delaying package configuration, since apt-utils is not installed What does this mean? And once I have installed apt-utils…
David
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Dump a linux process's memory to file

Is it possible to dump the current memory allocated for a process (by PID) to a file? Or read it somehow?
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