CentOS is a Linux distribution standing for "Community ENTerprise Operating System" and is a rebuild of "Red Hat Enterprise Linux" (RHEL). The "CentOS6" tag refers to versions 6.x of CentOS.

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1answer
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Excessive number of sleeping processes in CentOS - howto diagnose? [closed]

I have a a large number of sleeping processes, about 600, the majority of which are Apache processes. Should I kill all these sleeping processes, or will that make Apache fail completely? Why are ...
5
votes
2answers
2k views

Is there a big difference between CentOS 6.4 to 6.2 and should I up/down-grade?

We have two separate managed web servers. One is running CentOS 6.2 and is used as a production environment for a number of sites. The second one runs CentOS 6.4, and hosts some internal applications, ...
-2
votes
1answer
2k views

How do I open custom ports in my iptables firewall? [closed]

I need IPTables, like everyone else, but I don't use it enough to really keep my knowledge complete and fresh. The setup utility in CentOS is too basic. It doesn't seem to allow me to open up custom ...
32
votes
2answers
80k views

How do I configure LDAP on Centos 6 for user authentication in the most secure and correct way?

During the last couple of days I have been using a lot of F-words, while browsing Internet for good documentation about how to setup an LDAP-server. So far I have found none, but plenty that are less ...
13
votes
2answers
39k views

Upgrade CentOS 5.x to CentOS 6.x - tips and techniques

Now that CentOS 6.0 is making its way to the various mirror sites, I wanted to solicit opinions on the upgrade process. In working with the commercial RedHat 5.6 and 6.x distributions for the past few ...
1
vote
1answer
284 views

Apache fails silently after installation of MapServer 6.2.0

THIS QUESTION SHOULD BE MARKED AS CLOSED I've recently compiled MapServer 6.2 on a CentOS 6.3 machine, using ./configure --with-ogr=/usr/bin/gdal-config --with-gdal=/usr/bin/gdal-config --with-proj=...
22
votes
3answers
49k views

How do I upgrade to the latest PHP version in CentOS with yum?

I found some blog posts about this, but it's rather lack of descriptions on possible side effects. I could really use some detailed on these steps: How to add a repo that provides PHP 5.4 into yum ...
7
votes
2answers
12k views

How do I view the contents of a SELinux policy package

As the title says, how do I view the contents of a SELinux policy package? The resulting files end with .pp. I'm running on centos 6, but I guess it's the same way on "all" distros. For example ...
13
votes
2answers
6k views

Persist IP address alias across reboots in CentOS/RHEL 6 using “ip” command

I've always used the ifcfg-eth0:1 alias files to create additional addresses. However, in recent rhel documentation, it states that: As the ip command of the iproute package now supports assigning ...
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 ...
20
votes
3answers
44k views

ipmitool - can't find /dev/ipmi0 or /dev/ipmidev/0

Based on a previous question, I installed ipmitool (yum install ipmitool). Even after a reboot, though, i get the following error when trying to run ipmitool power status: Could not open device at /...
9
votes
3answers
27k views

Changing the maximum mail size in Postfix

When sending large email to a new CentOS6 server running Postfix as the MTA, the following message is returned: tried to deliver your message, but it was rejected by the recipient domain. We ...
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
2answers
3k views

HP DL380p Gen8 (p420i controller) I/O oddity on XFS partitions

On DL380p gen8 servers using XFS on top of LVM on top of raid 1+0 with 6 disks, an identical workload results in a ten-fold increase in disk writes on RHEL 6 compared to RHEL 5, making applications ...
5
votes
6answers
2k views

Reloading a kernel “live” in CentOS / RHEL 6

When upgrading the kernel package on CentOS or RHEL 6, is it possible to load the new kernel without rebooting? My gut tells me it's not, but if it were, it'd be handy - especially when compiling ...
2
votes
1answer
6k views

Howto enable SMPTS (465) postfix CentOS

I need help is enabling SMTPS. I use postfix , dovecot with MySQL(virtual domains). I do not know how to enable SMTPS(465). I already added tls related settings and key and certificate in the "/etc/...
2
votes
1answer
18k views

Failed to retrieve directory listing in Filezilla connecting to vsftpd

newbie here. At first I was unable to connect to vsftpd but I added port 21 in iptables (i'm running on Centos 6) and managed to make it work. But now, I can't get past Command: LIST in Filezilla ...
5
votes
2answers
2k views

Modify XFS filesystem creation parameters during kickstart installation

I'm streamlining the kickstart process for a series of EL6.2 (RHEL, CentOS, SL, etc.) systems. I'd prefer to use XFS over ext4 for the growth/data partition. However, I'd like some control over the ...
3
votes
3answers
6k views

Safely update php 5.3.3 to >=5.3.4 on centos 6

Would the following works fine without any issues? I have apc cache installed, the other packages the usual php configuration. yum update php would that be enough? it is an active server, so want ...
18
votes
3answers
22k views

CentOS 6 and upstart

The new CentOS 6 comes with Upstart, replacing init. I am trying to convert an /etc/inittab file to the new upstart format. This particular server only has 15 or so inittab entries, however, other ...
14
votes
9answers
36k views

CentOS 6 and locale error

I just installed CentOS 6 and whenever I login to the system via SSH remotely, I get the following error: -bash: warning: setlocale: LC_CTYPE: cannot change locale (UTF-8) When I type "locale" on ...
8
votes
5answers
8k views

Install PHP7 from Remi repo

I installed PHP7 from Remi repo with sudo yum -y install httpd sudo yum -y install epel-release wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm sudo rpm -Uvh remi-release-6*.rpm ...
12
votes
6answers
12k views

PECL command produces long list of errors

Currently running PHP 5.4 on CentOS 6.5. I installed the webtatic php55w package then installed PEAR+PECL without issue along with redis and mongo through PECL. Shortly after, I realized 5.5 is not ...
7
votes
2answers
18k views

How do I get openldap on Centos 6 to write anything to it's log files

I don't get any information in my log file for openldap on my Centos 6 server. This is how i configured it. SELinux is disabled at the moment. First created a folder where I'd like to store the log ...
12
votes
4answers
33k views

In CentOS 6.x, how can I upgrade to Kernel 3.4?

I have a server running CentOS 6.2 with kernel version 2.6.32, but I need to increase my application Performance. The Kernel Version 3.4 has x32abi which can improve the performance so i want to ...
9
votes
2answers
21k views

What is the correct way to load modules for iptables on Centos 6

Where should I load iptables modules, for example ip_conntrack and ip_conntrack_ftp. Places I have found that might be candidates, but are they? The IPTABLES_MODULES variable in /etc/init.d/...
4
votes
1answer
1k views

Setup default page for Apache Virtual Hosts

We are running Apache on a server with multiple VirtualHost entries. Whenever someone access the server by it's IP address (http://198.147.xx.xx), one of the websites that is a VirtualHost comes up. ...
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 ...
6
votes
2answers
18k views

SSH sessions terminate abruptly with message: Corrupted MAC on input. Disconnecting: Packet corrupt

We have a Dell PowerEdge 840 Server running CentOS 6.0 64 bit with 2GB ECC memory. When any user sshs in, after some time the session gets terminated with the output: Corrupted MAC on input. Packet ...
6
votes
3answers
15k views

OOM killer killing things with plenty(?) of free RAM

The OOM killer seems to be killing things despite having more than enough free RAM on my system: (Full resolution) (Full resolution) 27 minutes and 408 processes later, the system started ...
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 ...
3
votes
2answers
5k views

Incrond running but not executing commands CentOS 6.4

I have copied this question over here from StackOverflow... I have installed incron from the EPEL repository (0.5.9) (before you ask; YES, I also tried downloading the source and compiling locally (0....
6
votes
1answer
8k views

Processing Conflict: mysql55w-libs-5.5.36-3.w6.x86_64 conflicts mysql-libs < 5.5

I'm trying to install the latest webtatic MySQL 5.5 edition via yum (http://webtatic.com/packages/mysql55/) on CentOS 6.5 but every time I try I get the following output ending in error: # yum ...
5
votes
1answer
738 views

IPSec + L2TP + NAT-Traversal does not work for multiple clients behind same nat

I have recently configured a VPN server hosted in AWS EC2. Details: Centos 6.4, openswan, xl2tpd, NAT-traversal. The configuration works great for a scenario when only one user connects form a given ...
4
votes
3answers
1k views

Update from zfs-0.6.2-1.el6.x86_64 to zfs-0.6.3-1.el6.x86_64 has made by zpool unreadable

After running # yum update zfs and restarting my CentOS 6 ZFS on Linux system can no longer see or interact with it's zpools. # zpool status no pools available # zpool import zpool: ../../lib/libzfs/...
2
votes
0answers
994 views

Adaptec 5805 on Centos 6 IRQ 16 error

I'm having a problem with Adaptec 5805 raid card http://www.adaptec.com/en-us/support/raid/sas_raid/sas-5805/ (with two SAS discs in raid) and Gigabyte motherboard GA-H67A-D3H-B3 http://www....
1
vote
1answer
289 views

Which kernel parameters should be adjusted to fix RX overruns?

I have a Centos 6 server that handles a lot of traffic. I see RX overruns increasing all the time: RX packets:11191345002 errors:0 dropped:0 overruns:35592596 frame:0 TX packets:15262461573 errors:0 ...
6
votes
5answers
21k views

Trying to understand the correct way to create a static route in CentOS, please assist

I've been trying to understand what's the correct way to add a static route on a CentOS 6.x machine. In some forums they say to create a file named route-dev_name (for example route-eth0) with the ...
5
votes
3answers
17k views

Howto install php 5.2.17 on centos 6 x86_64

Does anyone know how to install php 5.2.17 on a 64bit centos 6 install? I've got a old legacy system that requires php 5.2.17, but centos 6 only supports php 5.3. I've installed repo's such as ...
3
votes
3answers
14k views

Enabling http access on port 80 for centos 6.3 from console

Have a centos 6.3 box running on Parallels and I'm trying to open port 80 to be accesible from outside tried the gui solution from this post and it works, but I need to get it done from a script. ...
2
votes
1answer
10k views

telnet unable to connect to remote host

I have installed postfix and devcot on one of my live servers to send bulk mail (system messages on sign-up, wrong passwords etc). I use the php_imap function to check bounces and flag those email id'...
2
votes
1answer
3k views

What is “state RELATED,ESTABLISHED” in iptables? [duplicate]

2064 871K ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED 0 0 DROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp flags:0x3F/0x00 0 0 DROP tcp -- * ...
2
votes
3answers
6k views

How can I install pam_mount on Centos 6 x86_64?

I need to use pam_mount to mount user home directories individually at the time that each user logs in. I cant locate a package for this, at least for Centos 6. I would not have a problem building ...
2
votes
1answer
12k views

centos6 apache2 Invalid Command SSLEngine

Running: CentOS6 x64 When I restart httpd, I get the following error. What am I missing? [root@localhost ~]# service httpd restart Stopping httpd: [ OK ]...
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vote
2answers
3k views

Is subscription-manager available for CentOS?

I'm trying to fix my updater to point to a specific release. Is the subscription-manager for RedHat only? I don't see it in my CentOS 6.3 (yum) repository.
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3answers
3k views

How to install php56 on CentOS 6 x86_64

When I run yum install php php-devel php-mysql php-gd php-mbstring, it will install php5.3. yum list installed *php* Loaded plugins: fastestmirror, security Loading mirror speeds from cached hostfile ...
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votes
1answer
1k views

CPanel installation on Azure CentOS, gcc install fails

I am trying to install CPanel on a Centos VM on windows azure. Yum is failing to install gcc, which is required by the cpanel installer. I am getting this Error: Package: glibc-2.12-1.80.el6.i686 (...
5
votes
1answer
2k views

Unable to re-enable SELinux

Up until now we have disabled SELinux as our Standard Operating Procedure -- before you tell me off, I know. That's why we're enabling it now we've got time to. Our normal procedure was to: Set ...
5
votes
3answers
6k views

Interpreting cryptic kernel “page allocation failure” messages

I have a multi-user CentOS 6.1 database system running an application named ABC. The server is 64-bit, 8GB RAM and 6 vCPU (on VMWare ESXi 4). We get frequent dumps into the dmesg and the system logs ...