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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8
votes
1answer
1k views

Block outgoing connections for certaing uids (root, apache, nobody)

With iptables in CentOS 5 and 6 Linux - how can you please prevent processes running as root, apache or nobody from initiating outgoing connections? On CentOS 5 Linux I've tried putting these lines ...
8
votes
1answer
6k views

Interpreting munin graph and committed memory

I've been noticing that my server has been using swap a quite more often now but I can't seem to figure out why. The munin graph shows that the apps memory usage is about 0.7G out of the 1.5G. The ...
8
votes
3answers
26k views

Upgrade cURL to latest on CentOS

I need to upgrade cURL to the latest version on Centos 2.6.18-164.15.1.el5.centos.plusxen #1 SMP Wed Mar 17 20:32:20 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux I'm unable to find any suitable ...
8
votes
2answers
29k views

yum equivalent of “apt-get purge”

I want to reinstall a package on CentOS and start from scratch. In Debian, I can do a apt-get purge foo and it'll remove all config files for foo. yum remove foo doesn't remove the config files. Is ...
7
votes
10answers
6k views

Which linux version to install: i386 or x64?

Talking about ease of maintanence / software support does it matter what version of linux i386 or x64 version is installed? Server obviously is 64 bit however i wonder if living with 64bit OS would ...
6
votes
1answer
2k views

systemd: how do I view journals with journalctl without switching to root on CentOS 7?

If I run journalctl as nonroot, I would get the following message: No journal files were found. But switching to root, or using sudo gives me the journal. How can I view journals without switching ...
6
votes
2answers
1k views

yum update entire release but limit to a prior version

We need to update yum update but we want to stay one release back. For example, we have CentOS 6.2 and want to move to 6.3. By default, it looks like yum update will install 6.4. On RedHat, this ...
6
votes
3answers
8k views

Multiple Memcached server /etc/init.d startup script that works?

I install memcached server via source and can get standard start up script installed for 1 memcached server instance, but trying several scripts via google, can't find one that works to manager auto ...
5
votes
2answers
16k views

How to run script on first boot?

I need to run some bash script only once on first boot (after OS installation) of my CentOS machine This script should run before network service start (because this script will change network ...
4
votes
4answers
10k views

Flush-0:n processes causing massive bottleneck

I have a LAMP cluster that shares files via NFS and occasionally one of them will be stricken for a while when mysterious flush processes start appearing. Can anyone help me? The only way to resolve ...
4
votes
5answers
19k views

certutil: function failed: security library: bad database

when I'm using certutil it returns this error: certutil: function failed: security library: bad database. e.g. I can't list certs or keys How Can I fix this?
3
votes
2answers
14k views

Upgrade curl to latest on CentOS 6.3

Thought this would be a simple process, but I guess not. I need the latest version of CURL (7.23 or newer) on CentOS 6.3. If I do this: sudo yum upgrade curl It just tells me there is nothing ...
3
votes
4answers
8k views

Setup “open files” limit in Linux per user. Cannot setup more than 1024

I try to increase open file limit for certain user on CentOS 5.5 Linux. I added a new line to /etc/security/limits.conf: seed hard nofile 10240 Then do test: runuser -s /bin/bash - ...
3
votes
5answers
19k views

Installing Tomcat on CentOS 5

Disclaimer: I am not a server admin, I am a windows user that has lead a life of sinful installation wizards and drag and drop I'm attempting to install Tomcat on CentOS 5 hosted by a MediaTemple ...
2
votes
1answer
2k views

A proper way to create a chrooted SSH on CentOS 7 [closed]

There are a lot of tutorials of how to create a chrooted SFTP, but I would like to use SSH, because it is much faster to simply wget, unzip, mysql and mysqldump than tossing around the FTP and ...
2
votes
4answers
8k views

How do I cleanly remove ruby 1.8.7 from CentOS 5?

How can I cleanly remove my ruby version 1.8.7 from CentOS 5? I installed it by downloading the source code and performed a make.
14
votes
3answers
13k views

Official online RPM package browser / search for CentOS

I am looking for something that resembles packages.debian.org Debian Package Browser only for CentOS 5 and/or RHEL 5 [Red Hat Enterprise Linux].
11
votes
6answers
15k views

Yum doesn't install latest version of Git on Centos6

When I go to Gits download section it mentions that latest version is 1.8 and I can install it by yum install git on Fedora. I'm running CentOS6 so that command should also work for me, but yum tells ...
8
votes
2answers
1k views

VMWare vCenter/ESXi with FreeIPA instead of Active Directory?

Can vCenter authenticate against FreeIPA instead of Active Directory? If so, how would you set it up? We have a pure Linux environment (CentOS) and need to have vCenter and our VM's have the same ...
8
votes
2answers
17k views

Too many TIME_WAIT state connections! [duplicate]

I've been reading about this everywhere all day, and from what I've gathered, TIME_WAIT is a relatively harmless state. It's supposed to be harmless even when there's too many. But if they're jumping ...
6
votes
9answers
9k views

Make identical copy of Centos

I have a CENTOS server running and i want to make identical copy of it(all software,users), like twin server for mirroring purposes. how do i do that?
5
votes
4answers
14k views

Setting new hostname on CentOS, it changes back after restart

On CentOS (5.x) I have a VPS that has hostname set to "olddomain.com", at least this is the domain I am getting when typing "hostname" command. I want to change it to 'localhost.localdomain' because ...
5
votes
2answers
16k views

How to setup Ruby and RubyGems on CentOS?

I have a CentOS 5.5 (64-bit server) I'd like to install Ruby 1.8.7 (current patch level) and RubyGems What's the best way to go about this? disclaimer: I'm a CentOS noob
5
votes
3answers
3k views

lsync, unison or some other inotify auto-syncing tool..?

I have an app farm which generates thumbnails and makes them available to a web server farm using nfs. However the performance is so poor so I am going to make a local copy of the files on each web ...
4
votes
3answers
1k views

Compiling kernel version >= 2.6.34 on CentOS 5: RAID set “ddf1_foo” was not activated?

I want to mount a Ceph FS on some CentOS 5 servers. Since the ceph-fuse failed with below errors: # ceph-fuse --no-fuse-big-writes -m 192.168.2.15:6789 /mnt/ceph/ ceph-fuse[7528]: starting ceph ...
4
votes
2answers
8k views

CentOS - Yum - Specify Mirror

Is it possible to specify a mirror for YUM to target when doing updates? I've noticed on my CentOS 6.2 servers that it takes up to a minute for YUM to respond from a given command. I did some Googling ...
4
votes
4answers
2k views

Repositories for CentOS that don't suck?

I'm used to using ubuntu/debian repositories and they are great. I can apt-get just about any package and it'll be there. I have not found this on centos. I called my hosting company and they suggest ...
4
votes
5answers
6k views

Curl development headers with SSL support for Phusion Passenger 3

I'm trying to install phusion passenger nginx module, but it fails # passenger-install-nginx-module * Curl development headers with SSL support... not found ... yum install curl-devel Setting up ...
4
votes
6answers
3k views

JFS or XFS or anything else?

After deciding to use LVM2 as volumemanager on our servers there was also the wish for an online resizeable filesystem. After reading a few articles I decided to use JFS in favour of XFS. Now today I ...
3
votes
1answer
9k views

Nagios - check_ntp_time - Offset Unknown

I have a local NTP server running on the subnet to keep other subnet nodes in sync, without every node syncing with upstream servers. But, while implementing the check_ntp_time plugin for Nagios I am ...
3
votes
3answers
2k views

Assigning Processes to CPU Cores

I have access to a CentOS 6 web server (a PHP/MySQL forum) running Apache 2.2.15 and MySQL 5.1.52. This box has dual oct-core Xeons. What I find looking over the CPU graphs is that the first two ...
3
votes
1answer
4k views

How can I rate limit SSH connections with iptables?

I'm trying to limit the number of possible SSH connections to my server but it just seems to lock me out every time. I'm not very familiar with iptables but I've been reading up on the rules that I ...
3
votes
1answer
2k views

Can Apache Read The GlusterFS Brick Directly But Write To The GlusterFS Mount?

I currently have 2 web servers (CentOS 5.5) and am using GlusterFS as client/server on both using Automatic File Replication. For both webservers: The GlusterFS mount point is: ...
3
votes
2answers
222 views

What issues should I watch for when rolling out CentOS as a desktop environment?

I have been managing Debian, and now Ubuntu, desktop systems for a small shop for several years now. I am very comfortable with apt for package management and distribution upgrades. The Ubuntu ...
2
votes
1answer
558 views

How to configure SELinux to allow apache to run git

I have a CentOS 6 server and I'm trying to get the apache web server to run git pull in a directory. The php file is simply: <?php shellexec('cd /var/www/vhosts/domain;git pull'); However, ...
2
votes
3answers
7k views

sshd running but no PID file

I'm recently started using monit to monitor the status of sshd on my CentOS 5.4 server. This works fine, but every so often monit reports that sshd is no longer running. This isn't true - I am still ...
2
votes
2answers
4k views

Finding Nginx/PHP-FPM bottleneck that is causing random 502 gateway errors

I work for a rather busy internet site that is often gets very large spikes of traffic. During these spikes hundreds of pages per second are requested and this produces random 502 gateway errors. Now ...
2
votes
6answers
936 views

24 Core Server Performance

I have a quad hexacore system based on the Opteron 8345 chips - that's 24 cores in all with 48GB of ram. This box was meant to replace the current six Intel core box which my current LAMP stack runs ...
2
votes
2answers
983 views

How can I verify which repository a package resides on in Centos?

I'd like to know which Centos repositories various packages are available at. Is there a directory somewhere? I tried googling it and didn't find anything.
1
vote
1answer
506 views

Send email through Gmail SMTP to avoid local delivery attempts?

Background We use Google Apps for email with our domain example.com: [ec2-user@example ~]$ dig MX example.com … ;; ANSWER SECTION: example.com. 300 IN MX 1 ...
1
vote
1answer
4k views

ptp time synchronization on centos6/rhel

I need to setup time synchronization using PTP (precision time protocol). I'll get server address. I found ptpd server (version 2.1). I created startup files in /etc/init.d. But wondering what options ...
0
votes
3answers
2k views

Centos Dedicated Server Security [closed]

We have clean CentOS 5.6 setup and virtualmin on it, that's all. What type of security steps would you suggest are appropriate? http://www.wiredtree.com/supportservices/servershield.php this page ...
0
votes
2answers
2k views

How to keep SpamAssassin up to date under CentOS?

I am running CentOS 5.4 with SpamAssassin installed via yum. However the version yum installed was SpamAssassin version 3.2.5 and I am finding that this version has many outdated rules -- including a ...
-2
votes
1answer
11k views

PPTP IPTables routing issue

PPTP connects just fine to the radius server PPTP modules are loaded into the kernel PPTP connects fine to the pptp service Question: How do I get the PPTP to connect to the internet? IPTables: ...
12
votes
4answers
9k views

Should I avoid putting two SSDs in a RAID1 configuration due to performance degradation?

I have a workstation system that will have two 64GB industrial SSDs, and the plan is to have both disks in a RAID1 configuration for redundancy which is set up in the kickstart. The system will be ...
11
votes
2answers
13k 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 ...
10
votes
5answers
10k views

Allow root login from one IP address only

I have centos5. Is there any way that i can log into my vps server with root user from particular ip address only. I have read that i can use private key to login into sshd. But the problem is i am ...
8
votes
1answer
6k views

CentOS, two nics eth0 eth1 with different subnets aren't reachable outside VLAN/subnet

I am having an issue with a CentOS 6.3 box. We have two NICs (eth0 and eth1) in the server which each have an ip from a different subnet assigned, let's say eth0:192.168.1.2/24 (gateway 192.168.1.1) ...
8
votes
3answers
10k views

How do I change Dovecot virtual user passwords?

I used one web based control panel to create some virtual users for Dovecot. That control panel no longer works so I need to do this manually. I need to reset the password for one (virtual) user ...
8
votes
6answers
12k views

CentOS How Much SWAP for 16GB of RAM?

How much SWAP would you give a CentOS install on a dual Quad Core XEON with 16GB of RAM that is going to be running a php website with a mysql backend - medium/heavy load?