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

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13
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2answers
30k 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 ...
3
votes
2answers
2k 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 ...
5
votes
2answers
870 views

Timezone for cron jobs

We have a VDS running CentOS 5.5 that was created and configured with the EDT timezone. I have replaced etc/localtime with a link pointing to the Australia/Melbourne (UTC+10) timezone file. Running ...
4
votes
5answers
11k views

Upgrade Centos 5 tot PHP 5.2 or 5.3 [recommended way?]

We are using Zend Framework and in version 2, php 5.2 will be the minimum requirement. We love CentOS and we'd like to keep using it, but PHP 5.1 just won't do anymore when developing web applications ...
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
1answer
612 views

Create swap file on a running Linux machine

Our company web sites have just been moved from a shared host to a VDS, as the hosting company plans on retiring the less than completely reliable shared hosting server(s). The VDS only has 256MB of ...
6
votes
3answers
20k views

How do I tell what process is causing kswapd to be in use?

I see kswapd using 100% CPU... how can I tell on which process's behalf kswapd is being used so much?
1
vote
1answer
172 views

Why servers error log states lots of file doesn't exist, but files are accessible and website works well

we migrated our website onto VPS server (CentOS 5.6 + Plesk 9.5), everything works nice, but one strange thing that i noticed in Plesk, is error_log file, most of the time it filled up with hundreds ...
1
vote
2answers
6k views

how to install git on CENTOS 5.5

How can I install git on CENTOS 5.5 machine? I tried to install it from yum but got following msg. root@host [~]# sudo yum install git Loaded plugins: fastestmirror Loading mirror speeds from cached ...
2
votes
3answers
244 views

What is the equivalent of packages.debian.org for CentOS?

I have a CentOS machine that is not connected directly to the internet. I need to install some packages manually. If this were Debian I would go to packages.debian.org, search for the package and ...
2
votes
2answers
2k views

Setting up vsftpd with users locked to specific directory

I setup vsftpd, and changed the chroot settings in the vsftpd.conf file. But how do I make a user able to access only /var/www/html/username_here/ I made the user with useradd, but what's next? ...
1
vote
1answer
142 views

Apache on CentOS 5.9 VM serves modified files incorrectly

Edit: this has been almost entirely rewritten as I've narrowed down the issue. I'm using a Vagrant VM to mirror the client's environment as closely as I can. I'm using VirtualBox 4.3 (with Guest ...
1
vote
1answer
3k views

Loading JSON in PHP53: ZVAL_DELREF in Unknown on line 0

I'm trying to loading JSON into the new-installed PHP5.3.1 on a CentOS server. Previously there was a PHP5.1 or near and due to the latest version of WordPress I had to upgrade the PHP. I tried to ...
0
votes
2answers
877 views

Postfix load balancing

I have 4 VPS servers, my plan is to use one of these VPS servers as a load balancer which sends mail received by it from another server to other 3 VPS (smtp) clients who will relay mail to the outside ...
4
votes
2answers
12k views

How to upgrade to latest PHP, MySQL, and phpmyadmin on CentOS 5.8 (32bit)?

I have searched around on the internet and cannot find a reliable source for installing the latest versions of PHP, MySQL, and phpmyadmin on CentOS 5.8 32bit with apache. I have tried a couple times, ...
2
votes
2answers
4k 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 ...
2
votes
2answers
10k views

Apache 2 Symbolic link not allowed or link target not accessible

My apache server runs as user foo. I have some Rails applications in /home/foo/app1 /home/foo/app2. Each of them has an vhost <VirtualHost *:80> ServerName app1.foobar.com ServerAlias ...
0
votes
2answers
3k views

DNS Server Spoofed Request Amplification DDoS - Prevention

I've been conducting security scans, and a new one popped up for me: DNS Server Spoofed Request Amplification DDoS The remote DNS server answers to any request. It is possible to query the ...
4
votes
3answers
756 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 ...
5
votes
3answers
4k views

Clear / Flush cached memory [duplicate]

I have a small VPS with 6GB RAM hosting a couple of websites. Recently I have noticed that my cached memory size is quite high - see below: Cpu(s): 0.1%us, 0.1%sy, 0.0%ni, 99.1%id, 0.0%wa, ...
5
votes
1answer
655 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 ...
2
votes
2answers
152 views

CentOS 5 extremely slow when is running a download

When my server is downloading a file or executing other IO operations the other server functions become extremely slow (almost locked). Even other functions that do not use the network. When a ...
1
vote
3answers
2k views

How to view linux hidden process and remove rootkit

I and just installed OSSEC and it is telling this Process '2517' hidden from /proc. Possible kernel level rootkit. Excessive number of hidden processes. It maybe a false-positive or something really ...
0
votes
1answer
234 views

Server not responding to pings on external interface

I'm sure this is an easy routing question, but I've been banging my head over it for hours now. Centos 5. eth1 private. 10.0.0.12/24 gw 10.0.0.1 eth0 public 216.234.x.x gw 216.234.x.x route command ...
0
votes
1answer
5k views

Adding root certificate to CentOS 5

Recently one of my machines was put behind a proxy meaning some programs I had working no longer do. When i try to do "openssl s_client -showcerts -connect remoteserver:remoteport" it presents me ...
0
votes
3answers
2k views

How to instal the PHP MCrypt + library (libmcrypt) on CentOS 5 server

I'm trying to install mCrypt for PHP on my server, and before that I've found that I need to install libmcrypt as well... I cannot find any instructions via google that actually work for this, ...
0
votes
3answers
1k views

NTP time sync not working in a DOMU Centos 5.5 server

I have a Xen Centos 5.5 server with ntpd working in virtual server. NTP time sync seems not working. I have disabled any firewall. my grep -i ntpd /var/log/messages output: Apr 1 16:15:47 ...
6
votes
2answers
870 views

ntlm_auth - can login in AD with both old and new passwords

I have problem with AD and ntlm_auth. I use the following command, to query the AD server for checking the user existence: ntlm_auth --use-cached-creds --username=SOME_USER --password=SOME_PASS ...
3
votes
1answer
2k views

OpenSSL handshake failure

We were recently forced to migrate our production cloud servers from GoDaddy to Azure because GoDaddy is ending thier cloud server service. One of our servers was a CentOS 5.7 running a JasperReports ...
3
votes
6answers
2k views

I think my server is being hacked. What should I do? [duplicate]

I'm not a server admin and I have very little experience in "debuging" a server. But from looking at my log files, it looks as if I'm being hacked. But I have no clue to what I should do :-/ I was ...
2
votes
3answers
874 views

Which services to disable on a CentOs 5.8 web/database server?

I have just setup my CentOS 5.8 64 [final] server as a webserver. Specs: 2x E5620 Intel CPU, DDR3 RAM, Hardware Adaptec RAID 10, 4x SAS drives. I have installed myself: Nginx PHP-FPM MySQL ...
2
votes
1answer
1k views

My CentOS 5.7 server can't access the internet

I have a CentOS 5.7 server setup in my office. I have recently moved to a new router (Linksys E3200) and I don't seem to be able to access the web at all through it (git, yum etc.). All the other ...
2
votes
3answers
880 views

Root file system is full and I need to install additional software.

I am trying to install to install EPEL Repository on CentOS 5.7. I still have lots of space available on my hard drive. /dev/sda2 3.9G 3.9G 0 100% / /dev/sda11 17G ...
2
votes
2answers
606 views

SELinux prevents Apache from writing to pgbouncer's Unix domain socket

I'm using freshly installed CentOS 5.7 Linux 64 bit with PGDG packages: # rpm -qa|grep -i PG postgresql-libs-8.4.8-2PGDG.rhel5 pgdg-centos-8.4-2 postgresql-8.4.8-2PGDG.rhel5 pgbouncer-1.3.4-1.rhel5 ...
2
votes
3answers
904 views

arp table filling up

I have a CentOS 5 system which serves as an IPSec VPN connector between my network and a couple of remote networks. Lately it is running into this problem once or twice a day where its ARP cache gets ...
2
votes
2answers
2k views

Installed php-mcrypt but it doesn't show up in phpinfo()

I'm trying to install php-mcrypt on a CentOS 5.4 but while the extensions appears to be installed, there's nothing about it when I do a phpinfo(). For example, you can see below that php-mcrypt ...
2
votes
1answer
3k views

HOw to check firewall rules in Centos

I have centos 5. I tried iptables -L and it gives the following output Chain INPUT (policy ACCEPT) target prot opt source destination RH-Firewall-1-INPUT all -- anywhere ...
1
vote
1answer
1k views

`GLIBC_2.7' not found

I have fpcalc installed on Linux and when I execute the following command: ./fpcalc I get an error saying: ./fpcalc: /lib/libc.so.6: version `GLIBC_2.7' not found (required by ./fpcalc) I ...
1
vote
2answers
351 views

Upgrade PHP on CentOs5

This morning I used yum upgrade to upgrade from php 5.1.6 to 5.3+ I then went to one of my sites and found that it had crashed, error establishing database connection. I found through this question ...
0
votes
1answer
173 views

How do I add eth0 on centos 5 that is using openvz

I have a vps account with CentOS 5 installed. It uses OpenVZ for virtualization. Now I'm trying to install pptp service (using this guide) on it. I'm currently on Step 6 but I don't see any eth0 ...
0
votes
1answer
359 views

High Load Average, low CPU and Memory Usage and minimum wait time for IO Operation (5%)

I have a VPS with the OS centos 5.7, and it is behaving very weirdly. My VPS is located on a 2-core machine. For a 2-core machine, the load average I can see is very high, as evident when I use the ...
0
votes
1answer
233 views

IP bases access control list script

I would like to setup ACL (python script or any ready made Centos compatible scipt) & limit rate for all IP addresses, who are hitting the site very frequently. For example crawlers, bots (except ...
0
votes
1answer
1k views

iptables error: No chain/target/match by that name?

After running following command: iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 5 -j SNAT --to-source 173.224.222.45 I get following ...
0
votes
1answer
441 views

OpenVZ kernel panic

I recently installed OpenVZ on my VMWare box (To do some testing) and I get the following: https://www.dropbox.com/s/p38btkv5j84bvsh/Capture.JPG the GRUB config is as follows: # grub.conf generated ...
0
votes
1answer
333 views

why “php -i|grep php.ini” is not finding the correct path to php.ini?

I know that my php.ini is located at /etc/php.ini but when i run php -i|grep php.ini I get this output Configuration File (php.ini) Path => /usr/local/lib there's nothing in that directory and i ...
0
votes
1answer
1k views

qlogic HBA tuning recommendations random iops

Trying to squeeze out the most performance from a 3PAR SAN with Qlogic HBA in our HP servers. We run on Centos 5.5 with latest updates/kernel. Can anyone give useful recommendation or tuning to get ...
0
votes
3answers
1k views

Lighttpd not starting - no error

I recently installed Lighttpd on Ubuntu Server 10.04 x86_64 and created several websites. What I do is include /etc/lighttpd/vhost.d/*.conf and put a configuration file for each website in that ...
-1
votes
1answer
83 views

dd test indicated that it took 51 second to transfer 1 kilobyte, VPS hosting provider claimed not responsible, how? [closed]

I did a dd test on my VPSs, for your information, I am purchasing a VPS with 5 node from tmdhosting. My result: Last login: Wed Apr 10 22:04:46 2013 from 115.85.128.54 ...