CentOS is a free (as in beer and speech) GNU/Linux distribution that is community driven and based on source code released from RedHat.

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17
votes
1answer
43k views

MySQL [Warning] IP address could not be resolved

I'm running MySQL5.6.3 on a CentOS 6.1 virtual machine running on Windows XP in VirtualBox. The network card is configured in bridge mode, so my physical & virtual machines share the same ...
16
votes
7answers
22k views

Automatically check for Security Updates on CentOS or Scientific Linux?

We have machines running RedHat-based distros such as CentOS or Scientific Linux. We want the systems to automatically notify us if there are any known vulnerabilities to the installed packages. ...
12
votes
1answer
2k views

Apache, suexec, PHP, suPHP

While I'm quite comfortable as a Linux user, my Linux Admin-fu is a bit weak. Thus, I'm here looking for guidance with a CentOS server I'm about to build. I need to setup an Apache2 web server for a ...
8
votes
4answers
21k views

how do I disable the nf_conntrack kernel module in CentOS 5.3 without recompiling the kernel

I'm running CentOS 5.3 and want to disable the nf_conntrack module to improve network performance for haproxy. I'm running iptables with some simple rules. I don't really need the connection ...
6
votes
9answers
4k views

Linux Server Performance Monitoring

I'm looking to monitor performance on my Linux servers (which happen to be Centos). What are the best tools for monitoring things in realtime such as: Disk Performance I/O, swapping etc.. CPU ...
11
votes
5answers
13k views

Install recent ImageMagick on CentOS 6.3

I'm having a terrible time trying to get a recent version of ImageMagick installed on a CentOS 6.3 x86_64 server. First, I downloaded the RPM from the ImageMagick site and tried to install it. That ...
5
votes
2answers
3k views

Tips for optimizing RHEL/CentOS kickstart workflow

I'm working in an environment that consists of CentOS systems located in multiple data centers and office locations. I've been using a reasonable kickstart with a solid post-install script, but want ...
3
votes
3answers
7k views

cakephp & nginx config/rewrite rules

Hi somebody please help me out, I've asked this at stackoverflow as well but not got much of a response and was debating whether it was programming or server related. I’m trying to setup a cakephp ...
2
votes
2answers
10k views

Mount a Windows DFS Namespace in Linux

I've got a Windows DFS setup with a few namespaces, and I need a way of accessing them via CentOS. Any ideas? I've had a look at CIFS mounting, but it won't support the namespace (each separate ...
30
votes
5answers
58k views

How do I change timezone in centos 6.2?

Here is the output of my date command: [root@r1304 ~]# date Wed Apr 18 15:43:28 GST 2012 I want to change the default system timezone to Asia/Dubai. I've followed a tutorial and did this: ln -sf /...
16
votes
2answers
22k views

CentOS /usr/local/lib system wide $LD_LIBRARY_PATH?

I install custom software in /usr/local/lib. How do I set the PATH and LD_LIBRARY_PATH in CentOS 6 system-wide to use /usr/local/lib. I realize there may be more than one way. What's the simplest and ...
13
votes
3answers
8k views

Linux containers (LXC) on Red Hat/CentOS EL6 - lxc-create versus libvirt?

It's tricky trying to stay within the good graces of Red Hat and still plan for system longevity... I've been a proponent of Linux Containers (LXC) for over a year. My initial installations were ...
2
votes
2answers
6k views

Setting up two NICs on two separate LANs provides error

I wish I had found this before starting in, but it's too late for that... I am running CentOS 5.5. I started following this guide for setting up two NICs on different networks. Everything was ...
19
votes
3answers
5k views

Should I be worried that yum update suddenly wants to update well over 100 packages on my CentOS 6 system?

I get an email alert whenever there's something to update, and typically do them that day. This tends to happen most days. For whatever reason I've had no alerts since 20th July until today (I ...
14
votes
4answers
6k views

Improving IO with FlashCache

I have a server with 2 HDD's (2x 1 TB), running in RAID 1 (SW-RAID). I want to improve IO performance by using flashcache. There are running KVM virtual machines on it, using LVM. Regarding this, I ...
7
votes
4answers
9k views

File audit in Linux: how to watch directory tree for deletions?

I have a forum script running on server and somehow small number of attachments begin to get lost. I want to find out what is deleting them and at what time. How can I setup Linux auditd (auditctl) to ...
4
votes
1answer
5k views

SELinux: Letting Apache talk to MySQL on CentOS

So I have chrooted MySQL into /opt/chroot/mysql, and everything runs fine. Apache is configured normally, and also runs fine. I created a small PHP script which connects to the MySQL Daemon, and ...
3
votes
1answer
1k views

Cent OS upgrade PHP

I'm in the midst of resolving a bunch of security issues on a clients server to get them compliant with credit card laws and such. The first order of business is getting php from 5.2.14 to 5.2.16. ...
8
votes
2answers
2k views

What can cause ALL services on a server to go down, yet still responding to ping? and how to figure out

It has happened to me already twice within very few days that my server goes down completely, meaning http, ssh, ftp, dns, smtp, basically ALL services stop responding, as if the server had been ...
4
votes
3answers
8k views

ldap force user to change password

I am using CentOS-ds (based off Redhat-DS and 389 directory servers). I have LDAP setup, and working to authenticate users (and Sudo, thats a handy feature!). even passwd is working great to change ...
3
votes
4answers
5k views

CentOS - PHP - Yum Install with Custom ./configure params

I have successfully configured and compiled php on my dev server, and works great, but after talking to a sysadmin buddy, he informed that custom compiles of the latest builds are not recommended for ...
2
votes
2answers
4k views

Kernel update without reboot [duplicate]

Possible Duplicate: Reloading a kernel “live” in CentOS / RHEL 6 How can i update kernel on Centos without reboot .? I found ksplice but it is not supported for Centos. Regards,
1
vote
4answers
3k views

Apache uses up a lot of CPU for small website

I have a CentOS 5.5 VPS server with 512MB RAM setup. There is 1 website hosted on it through Apache/PHP/MySQL which is built in Magento, a popular ecommerce framework. When I browse the website, it ...
1
vote
1answer
3k views

Puppet yum repo - Pull down 2.7.x vs 3.0.x

So a few weeks ago I started on the path to using puppet to automate all the configs/services. At the time I was using the EPEL repo, which installed version 2.6.x. After some reading I was trying to ...
1
vote
3answers
3k views

Centos Xen resizing DomU partition and volume group

I have a setup like so: Dom0 LV | DomU Physical Disk | | XVDA1 XVDA2 (/boot) (DomU PV) | VolGroup00 (DomU VG) ...
0
votes
2answers
4k views

SMTP server for centOS, other than Postfix? [closed]

I need to install smtp server on centOS, but I don't want to use postfix. please suggest some others smtp servers and how install using putty.
12
votes
2answers
14k views

Why is the chroot_local_user of vsftpd insecure?

I'm setting up on my VPS a vsftpd, and i don't want users be allowed to leave they're ftp home directory. I'm using local_user ftp, not anonymous, so I added: chroot_local_user=YES I've read in ...
12
votes
1answer
2k views

Linux - if I change the hostname, which services need to be restarted?

I'm making some system hostname changes across a few environments and this got me thinking... When I change a server's hostname (live), what needs to be modified and which system services require a ...
5
votes
1answer
2k views

How do I migrate from RHEL 5 to CentOS 5?

I've found myself in charge of installing some software on an old server running RHEL 5. Unfortunately, since it's just a development server now, it no longer rates a license. I'd like to continue ...
5
votes
3answers
2k views

iptables — OK, **now** am I doing it right?

This is a follow up to a previous question where I asked whether my iptables config is correct. CentOS 5.3 system. Intended result: block everything except ping, ssh, Apache, and SSL. Based on ...
4
votes
2answers
3k views

Email catch all (domain and subdomains) Postfix

I just want to catch all email sent to * @domain.com AND * @ * .domain.com to a unique email system@domain.Com @runlevel6 Any idea to implement regexp in virtual like cat /etc/postfix/virtual @...
3
votes
3answers
2k views

Changing Timezone, Centos Apache server

I'm trying to change my server's timezone. I was following this tutorial but I can't get it to change to Pacific Standard Time. ln -sf /usr/share/zoneinfo/EST localtime Will work, but ln -sf /...
3
votes
2answers
1k views

Unexplained cache RAM drops on Linux machine

I run a CentOS 5.7 64 machine with 24gb ram and running kernel 2.6.18-274.12.1.el5. This machine runs only Nginx, php-fpm and Xcache as extra applications. Since about 3 weeks my memory behavior on ...
2
votes
2answers
27k views

Postfix: lost connection with *somehost* while receiving the initial server greeting

I had Postfix installed on CentOS earlier (several months ago) and it was working fine. Due to the fact of the many brute-force attempts and considering that I didn't use it almost at all I shut ...
2
votes
3answers
1k views

Google Compute Engine Cent OS change hostname

Title says it all really - I want to change the hostname of a Google Compute Engine Cent OS instance. I have tried the normal method... in /etc/sysconfig/network set HOSTNAME=my.new.hostname in /...
2
votes
3answers
4k views

CentOS 5.5 remote kickstart installation stalls at “Starting install process.” How to debug?

I'm having a difficult time with a remote CentOS 5.5 kickstart installation on an HP ProLiant DL360 G6. This is in an environment where I maintain an internal CentOS yum repository. The kickstart ...
2
votes
4answers
7k views

Recommended method to upgrade PHP 5.1.6 to 5.2.x on CentOS 5.4

It's been awhile since this type of question was asked here. Perhaps the recommended solution has changed. I have a CentOS 5.4 mail server running RoundCube webmail. By default, RoundCube expects PHP ...
1
vote
4answers
1k views

CentOS Hot Backup

We have dedicated CentOS machine running a customer management service, in a few days development will cease and we would like to take a complete backup of the hard-disks. The server has 2 500GB hard-...
1
vote
1answer
640 views

Apache Dynamic Virtual Host with SSL [duplicate]

I have the following in my httpd.conf file NameVirtualHost *:80 <IfModule mod_vhost_alias.c> <VirtualHost *:80> ServerAlias * UseCanonicalName Off LogFormat "%V %h %l %u %t ...
1
vote
2answers
6k views

Centos: multiple IP addresses

I just bought 10 extra IPs from my host. How do I point these at my CentOS 5 server?
0
votes
1answer
547 views

installing SSL certs on apache … what certs to use?

Im an intermediate Linux user and got assigned the task to make Apache run https connections. Currently running centOS 6 and my problem is following: installed mod_ssl and tried to set up paths ...
0
votes
1answer
259 views

Linux (CentOS) - Is there any (feasible) way to add a file write “hook”?

I have a mod_security log parsing script to load data into a mysql database which is then accessed by our Project Management System to display recent flaggings by the rulesets for our developers. The ...
10
votes
4answers
24k views

iptables nat does not exist

Today my iptables nat on the host system stopped working and I have no clue what happend! (That's very bad, I know) All commands are executed as root user. If I run $ iptables -t nat -L I get the ...
5
votes
5answers
13k views

yum “ Segmentation fault” in centos

While using yum commands in a centos server(2.6.18-194.el5PAE #1), it throws 'Segmentation fault'. [root@server2 ~]# yum check-update Loaded plugins: fastestmirror Loading mirror speeds ...
4
votes
2answers
16k views

How do I fix “getaddrinfo: localhost Name or service not found” for telnet server?

I need to enable telnet (no i can't use ssh, and I don't want to discuss why I have to use telnet either), I have 127.0.0.1 localhost.localdomain localhost in /etc/hosts. I have installed telnet-...
4
votes
1answer
247 views

Allow SSH only on one of a servers IP addresses

I have a server with several IP addresses that hosts sites on each IP address. I have one ip address that does not have a site associated with it. I want to allow SSH login only to the one IP address ...
3
votes
2answers
3k views

Iptables port forwarding on OpenVZ CEntOS container

I am trying to setup a simple port forwarding on an OpenVZ container that is running CentOS 5.5. When I run a command I get errors. iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-...
3
votes
4answers
5k views

Restore default ownership in CentOS after terrible chown [duplicate]

Possible Duplicate: How do I recover a RHEL 4.3 server from bad permissions set over the entire filesystem? Is there any way to restore the default ownership of a CentOS filesystem after an ...
3
votes
3answers
5k views

Yum doesn't update httpd past version 2.2.3 on centos

I have a fresh CentOS vps (CentOS release 5.4 (Final)), and yum installs Apache/httpd version 2.2.3 but 2.2.14 is the latest release. Why doesn't yum install more recent updates?
3
votes
2answers
11k views

my.cnf missing on all directories after new mysql installtion

Title says it all. I previously had mysql version 5.1 on my CENTOS 6 x86_64 OS. I attempted to remove mysql 5.1 and replace it with an install of mysql 5.6. Here is my uninstall process for mysql 5....