CentOS is an Enterprise-class Linux Distribution derived from Redhat Enterprise Linux sources freely provided to the public.

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53
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10answers
79k views

Is CentOS exactly the same as RHEL?

I'm sure this question has been asked again and again elsewhere (I did not find anything specific to CentOS vs RHEL in SE), but I would still like to ask and confirm a few specific points. I am well ...
39
votes
2answers
65k views

CentOS 6 “Default” Installation Options

Can someone tell me the difference between a Desktop Install, a Basic Server install, and a Minimal Install? During installation, it doesn't give a description and I can't find documentation on it ...
29
votes
7answers
1k views

What's the equivalent to && when writing a bash script?

I apologize in advance if this is a duplicate question. I did make an effort to search/check before asking here. I'm comfortable with writing one-liners like this: foocommand && ...
24
votes
2answers
29k views

In CentOS, what is the difference between yum update and yum upgrade?

What is the difference between yum update and yum upgrade, and when should I use one over the other?
23
votes
5answers
39k views

How To Install Virtualbox Guest Additions On CentOS via Command Line only

Reading the Virtualbox user manual, I finally got [here], which explains how to install Virtualbox Guest Additions on a Linux guest via Command Line. But it's not clear enough for me (I just started ...
22
votes
7answers
87k views

How can I fix “cannot find a valid baseurl for repo” errors on CentOS?

I finished installing CentOS 6, but when I tried running yum update I got: [root@centos6test ~]# yum update Loaded plugins: fastestmirror, refresh-packagekit Determining fastest mirrors Could not ...
21
votes
2answers
15k views

How to colorize output of ls ?

I'm running CentOS in Linux text mode. When I run the command ls /usr/, the output is too hard to read (dark blue on black). How can I change the text coloring?
19
votes
5answers
18k views

How can I limit the bandwidth used by a process?

I have a CentOS 5.7 server that will be backing up its files nightly. I am concerned that visitors to the various sites that the server hosts will experience degraded performance while the backup is ...
19
votes
4answers
3k views

What makes CentOS “enterprisey” compared to “generic” distributions like Ubuntu?

What makes CentOS "enterprisey" compared to "generic" distributions like Ubuntu? When I say "enterprisey" I actually mean "better for server deployments". Just a general question, because I was ...
19
votes
5answers
95k views

How to create a FTP user with specific /dir/ access only on a Centos / linux installation

So I'm on a VPS - CentOS Linux installation. I have vsFTPd on the server. I currently have SFTP access to the server via my root user, but am now trying to create a new user with FTP access to a ...
19
votes
1answer
21k views

BUG: soft lockup - CPU# stuck for x seconds

I've seen a few bug reports and questions (on stackexchange and elsewhere) regarding a nagging "BUG: soft lockup - CPU#<n> stuck for <dt>s!". So far, I haven't found any clue as to what ...
18
votes
4answers
59k views

Why the default eth0 interface is down by default on CentOS?

I am already a little bit familiar with Linux distros like Debian or Ubuntu (yeah, very similar) but I wanted to try Red Hat based - CentOS 6.2 . I have installed it on my Windows 7 host in virtualBox ...
18
votes
1answer
25k views

what is the CentOS equivalent of /var/log/syslog (on Ubuntu)?

On ubuntu this file exists: /var/log/syslog. However the same file does not appear on CentOS Distributions. What is the equivalent file on CentOS?
17
votes
5answers
109k views

How to change hostname on centos 6.5?

Hi can't seem to change the hostname on my centos 6.5 host. I am following the instructions I found here: http://www.rackspace.com/knowledge_center/article/centos-hostname-change I set my /etc/hosts ...
17
votes
6answers
25k views

CentOS no network interface after installation in VirtualBox

I have Ubuntu 12.10 on which i installed virtual box on which I setup centos 6.4 i386. On Ubuntu I have: 3.5.0-17-generic kernal running. On virtual box I install centos 6.4 and everything works ...
16
votes
2answers
14k views

CentOS: List the installed RPMs by date of installation/update?

I'm on a CentOS machine. I updated and installed some packages a few weeks back, but I don't remember the name of every package or the names of every dependency. I used yum. Can I list the packages ...
16
votes
2answers
49k views

How to install Desktop Environments on CentOS 7?

I have recently installed CentOS 7(Minimal Install without GUI) and now I want to install a GUI environment in it. How can I install Desktop Environments on previously installed CentOS7 without ...
15
votes
7answers
6k views

Is there a difference of stability between Linux distros?

I've using Debian since 2010 for some home purposes and it has been stable. Is Debian still a good option if I need a server for heavy network, cpu, disk and memory usage? Last month I listened to ...
15
votes
11answers
64k views

Cannot enable network after CentOS 6.3 fresh install

I am trying to perform a fresh CentOS 6.3 installation then run various yum commands such as yum install httpd. The installation runs fine, however I cannot run any network based commands like yum I ...
15
votes
2answers
38k views

How to change the hostname of a linux machine using terminal?

I logged in for the first time, opened terminal, and typed in ‘hostname’. It returned ‘localhost.localdomain.com’. Then I logged as the root user in terminal using the command, ‘su –‘, provided the ...
14
votes
10answers
75k views

How to install CentOS 6 via USB mass storage device?

I want to install CentOS 6.2 on a laptop (Thinkpad R40) which comes without CD/DVD-drive but with USB 2.0 ports. It seems that CentOS does not provide ready-to-use dd-able USB images for ...
13
votes
7answers
40k views

“Symbolic link not allowed or link target not accessible” / Apache on CentOS 6

I've got a brand new CentOS 6 installation, which has a symlink in the document root to my development files: [root@localhost html]# ls -l total 4 -rwxrwxrwx. 1 root root 0 Sep 18 20:16 index.html ...
13
votes
2answers
1k views

Is it good to have multiple version of Linux Kernel?

Once, I was installing some kernel patches & something went wrong on a live server where we had hundreds of clients. Only one kernel was there in the system. So, the server was down for some time, ...
12
votes
2answers
22k views

How to install dig on CentOS 6?

I can't find the dig command on my new CentOS 6 installation. I've tried yum install dig but it say it cannot find the package. How do I install dig on CentOS 6?
12
votes
2answers
739 views

Accidentally deleted /etc/redhat-release file

I accidentally deleted /etc/redhat-release file. How can I restore or create a new one? I have CentOS Linux release 7.0.1406 (Core).
12
votes
2answers
9k views

( /etc/sysconfig/iptables ) “Manual customization of this file is not recommended.” Why?

Editing this file directly /etc/sysconfig/iptables can save me so much headaches so much time and so on... and yet on the very top of the file it says.. Manual customization of this file is not ...
12
votes
2answers
24k views

I Can't login as root with su command, but I can with SSH

How is it possible that I cannot log in as root by su root or su (I get incorrect password error), but I can log in by ssh root@localhost or ssh root@my_local_IP with the same password? I'm using ...
12
votes
1answer
44k views

CentOS - install using yum Apache 2.4

I need Apache 2.4 in CentOS because with Apache 2.2 mod_proxy_wstunnel is not possible. I have tried this, but unfortunately its for RHEL. After installing, I can't execute the Apache 2.4. Can anyone ...
12
votes
4answers
767 views

Using real time kernel headers to compile userspace code vs default headers

Per customer requirements, I installed CentOS 5.6 with the default kernel. With this kernel installed, the time.h file includes the #define CLOCK_MONOTONIC. Now, a real-time kernel was installed ...
11
votes
7answers
31k views

CentOS 7 Installation Failed

After hearing the news that CentOS 7 had been published, I decided to install it on my computer. I downloaded the ISO image from the CentOS official website (the one named ...
11
votes
2answers
2k views

Find out exact installation time of CentOS

I installed CentOS on my laptop about 8 month ago, and I want to know when exactly I installed it , how can I do that in CentOS 6.4 ?
11
votes
1answer
3k views

How can I monitor CPU usage by user?

I need to monitor CPU usage by users of two servers' (Ubuntu and CentOS). For example: user1 5% user2 10% ... Is there a tool similar to top or htop that can do that?
10
votes
1answer
861 views

How do you omit “./” when running scripts on current directory

On some tutorials over the internet they can run a script on the current directory without doing: ./script How do you omit this? I am using CentOS 5.6 x64. I want to run it this way script
10
votes
3answers
11k views

How can I know which IRQ is responsible of high CPU usage

I've moved a server from one mainboard to another due a disk controller failure. Since then I've noticed that constantly a 25% of one of the cores goes always to IRQ however I haven't managed myself ...
10
votes
2answers
3k views

Should you run automatic updates

I'm running production Centos web servers. I want to know what is best practice for running updates. Should I automate this with yum-cron or yum-updatesd? Or is there a danger of updates breaking ...
10
votes
4answers
33k views

Commands not found: netstat, nmap on CentOS 7

I'm using the following CentOS: $ cat /etc/centos-release CentOS Linux release 7.0.1406 (Core) The commands nmap, netstat and lsof are not found on CentOS7. Why? $ type -a nmap bash: type: nmap: ...
10
votes
1answer
26k views

ifconfig command not found

I've just installed CentOS7 as a virtual machine on my mac (osx10.9.3 + virtualbox) .Running ifconfig returns command not found. Also running sudo /sbin/ifconfig returns commmand not found. I am root. ...
10
votes
1answer
21k views

Setting up network from a “minimal” CentOS 6.4 install [duplicate]

Just installed CentOS 6.4 from a "minimal" ISO. On first boot, I discover that I cannot ping the outside world, yum update, or anything like that: connect: Network is unreachable. In fact, I can't ...
10
votes
2answers
12k views

Package bash-completion missing from Yum in CentOS 6

I am trying to get tab-completion working in Yum in CentOS 6 (so I can do something like yum install firefo<TAB> and get back firefox), and I have found many tutorials which say to simply do yum ...
10
votes
3answers
900 views

Why are files in my home dir being created as world-writable despite a more-restrictive umask?

I've realized that the permissions for new files and directories behave a bit strangely. First of all, umask seems to return the right answer: $ umask 0002 This means full access for my user and ...
10
votes
1answer
1k views

Creating a virtual microphone

I run a CentOS Server with VNC enabled and some services require a microphone to work properly, but it doesn't have to be used for recording, just a microphone device available. So I was wondering if ...
9
votes
4answers
3k views

/bin /etc /lib64 /root /sbin deleted or moved by mv folder/* /* while su

OS is Centos 6.5 64-bit I downloaded a tar file and wanted to untar and mv it. I untared, then accidentally (as root) ran mv folder/* /* instead of mv folder/* . bash said it couldn't overwrite some ...
9
votes
5answers
9k views

Limiting processes to not exceed more than 10% of CPU usage

I operate a Linux system which has a lot of users but sometimes an abuse occurs; where a user might run a single process that uses up more than 80% of the CPU/Memory. So is there a way to prevent ...
9
votes
9answers
14k views

Package: git-1.7.6.1-1.el5.rf.i386 (rpmforge) Requires: libcurl.so.3

After I run yum install git it shows the error Error: Package: git-1.7.6.1-1.el5.rf.i386 (rpmforge) Requires: libcurl.so.3 You could try using --skip-broken to work around the problem You ...
9
votes
2answers
15k views

how do I install the stock centos repositories?

I have a situation where the stock repo files that should exist in /etc/yum.repos.d/ (like centos-base.repo) are not present. I need to get them installed. I am sure this is simple, but after hours of ...
9
votes
3answers
36k views

Increasing Screen Size/Resolution on a VirtualBox Instance of Centos

I have VirtualBox instance of Centos 5. The screen size is quite small (800*600) and I'd like to increase it to 1280*1080. Under the Gnome preferences for "Screen Resolution" I only get the option for ...
9
votes
1answer
589 views

MySQL gets killed by OS every 25 days or so

About 4 months ago we migrated from MS SQL Server to MySQL 5.5. Since then we have been experiencing an issue once approximately ever 25 days since where CentOS runs out of memory and as a result it ...
9
votes
2answers
10k views

How to install packages to a custom location in centos6

I have a shared location, let me call it /tp I want to install all my libraries and packages in this location just like the default install. Reason to do this is: I want all the users in the network ...
9
votes
0answers
4k views

OpenSSL Package Rebuild CentOS 6.4 [closed]

Rebuilding openssl with Elliptic Curves on CentOS 6.4 The strategy is: 1) Download the "official" CentOS source package (.src.rpm) 2) Modify the .spec file to enable elliptic curves. (change no-EC ...
8
votes
2answers
84k views

Installing git “sudo: apt-get: command not found”

I am trying to install git. I run the following command: sudo apt-get install git-core git-gui git-doc But receive the following error: sudo: apt-get: command not found What should I do?