Memory use by which process Centos/RHEL/Fedora

# ps aux | awk '{if ($5 != 0 ) print $2,$5,$6,$11}' | sort -k2n

[root@microair ~]# ps aux | awk '{if ($5 != 0 ) print $2,$5,$6,$11}' | sort -k2n

PID VSZ RSS COMMAND

1960 4128 640 /usr/sbin/acpid

1706 6208 600 /sbin/portreserve

1781 6820 280 /usr/sbin/mcelog

1828 8404 368 /usr/sbin/fcoemon

396 11372 1408 /sbin/udevd

1815 12420 2636 /sbin/udevd

1816 12420 2408 /sbin/udevd

1803 13600 652 lldpad

2067 14912 596 tgtd

2068 14912 384 tgtd

2015 17856 1028 hald-addon-acpi:

1970 18156 1144 hald-runner

1767 19024 932 rpcbind

1 19408 1508 /sbin/init

2264 20088 408 dbus-launch

2014 20272 888 hald-addon-input:

2212 21544 392 /usr/sbin/atd

1941 23140 392 rpc.idmapd

1871 23396 1352 rpc.statd

1969 26524 5148 hald

2265 29648 912 /bin/dbus-daemon

1841 30080 1488 dbus-daemon

2158 32304 444 /usr/sbin/htcacheclean

144 36016 1352 /bin/plymouthd

1901 45020 488 /usr/sbin/wpa_supplicant

6667 49992 3956 /usr/libexec/polkit-1/polkitd

1856 55880 2320 /usr/sbin/modem-manager

2237 62312 416 /usr/sbin/certmonger

2082 66584 1228 /usr/sbin/sshd

2557 68876 1748 /usr/sbin/saslauthd

2559 68876 1664 /usr/sbin/saslauthd

2560 68876 1664 /usr/sbin/saslauthd

2561 68876 1732 /usr/sbin/saslauthd

2562 68876 1664 /usr/sbin/saslauthd

1852 80188 4416 NetworkManager

2108 93572 1688 /usr/sbin/exim

24965 100328 3984 sshd:

25145 106008 788 awk

2146 108116 804 abrt-dump-oops

2242 108516 1680 /bin/bash

1519 108520 1744 /bin/bash

24969 108520 1888 -bash

2134 110228 996 /usr/sbin/abrtd

25144 110244 1120 ps

2189 117256 1384 crond

2248 127460 16140 /usr/bin/Xorg

2268 131916 4084 /usr/libexec/gconfd-2

25146 155488 836 sort

2173 186424 5252 /usr/sbin/httpd

16817 186556 3684 /usr/sbin/httpd

631 186556 3684 /usr/sbin/httpd

632 186556 3804 /usr/sbin/httpd

633 186556 3756 /usr/sbin/httpd

634 186556 3684 /usr/sbin/httpd

635 186556 3784 /usr/sbin/httpd

636 186556 3684 /usr/sbin/httpd

637 186556 3684 /usr/sbin/httpd

638 186556 3848 /usr/sbin/httpd

1713 242988 1904 /sbin/rsyslogd

2253 251264 8452 /usr/bin/metacity

2251 270292 16956 /usr/bin/python2

2090 289524 196316 clamd

2047 381604 1652 automount

2246 412056 36420 /usr/bin/python2

6669 1031644 2480 /usr/sbin/console-kit-daemon

682 1106792 58480 /usr/bin/python

[root@microair ~]#

GPT(GUID Partition Table) problem during the linux installation on CentOS5.6

During the installation process of CentOS 5.6 one can face following error

Error: - "Your boot partition is on a disk using the GPT partitioning scheme but this machine cannot boot using GPT".

Reason:- This error mainly arises in the event where the total disk size is more than 2TB, irrespective of the primary partition disk.

Solution:-Enter the rescue mode and delete the MBR on the disk as below:-

#  dd if=/dev/zero of=/dev/sda bs=512 count=1

Reinstall the system again and it should work right.

How To Enable EPEL Repository in RHEL/CentOS 6/5

Why we use EPEL (Extra Packages for Enterprise Linux) repository ?
Provides lots of open source packages to install via Yum.
Epel repo is 100% open source and free to use.
It does not provide any core duplicate packages and no compatibility issues.
All epel packages are maintained by Fedora repo.

First, you need to download the file using Wget and then install it using RPM on your system to enable the EPEL repository. Use below links based on your Linux OS versions. (Make sure you must be root user).

For RHEL/CentOS 6 32-64 Bit
## RHEL/CentOS 6 32-Bit ##
# wget http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm
## RHEL/CentOS 6 64-Bit ##
# wget http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm
For RHEL/CentOS 5 32-64 Bit
## RHEL/CentOS 5 32-Bit ##
# wget http://download.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm
# rpm -ivh epel-release-5-4.noarch.rpm
## RHEL/CentOS 5 64-Bit ##
# wget http://download.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
# rpm -ivh epel-release-5-4.noarch.rpm
For RHEL/CentOS 4 32-64 Bit
## RHEL/CentOS 4 32-Bit ##
# wget http://download.fedoraproject.org/pub/epel/4/i386/epel-release-4-10.noarch.rpm
# rpm -ivh epel-release-4-10.noarch.rpm
## RHEL/CentOS 4 64-Bit ##
# wget http://download.fedoraproject.org/pub/epel/4/x86_64/epel-release-4-10.noarch.rpm
# rpm -ivh epel-release-4-10.noarch.rpm
How Do I Verify EPEL Repo?
# yum repolist
Loaded plugins: fastestmirror, priorities, refresh-packagekit, security
Loading mirror speeds from cached hostfile
epel/metalink                                            | 5.6 kB     00:00
 * base: centos.aol.in
 * epel: mirror.neu.edu.cn
 * extras: mirrors.digipower.vn
 * remi: fr2.rpmfind.net
 * rpmforge: mir01.syntis.net
 * updates: centos.aol.in
base                                                     | 3.7 kB     00:00
epel                                                     | 4.2 kB     00:03
epel/primary_db                                          | 5.8 MB     01:13
extras                                                   | 3.4 kB     00:00
rpmforge                                                 | 1.9 kB     00:00
updates                                                  | 3.4 kB     00:00
updates/primary_db                                       | 1.3 MB     00:29
repo id        repo name                                               status
base           CentOS-6 - Base                                          6,327+40
epel           Extra Packages for Enterprise Linux 6 - x86_64          9,712+518
extras         CentOS-6 - Extras                                              14
remi           Les RPM de remi pour Enterprise Linux 6 - x86_64        200+1,174
rpmforge       RHEL 6 - RPMforge.net - dag                              4,627+23
updates        CentOS-6 - Updates                                         254+43
repolist: 21,134
How Do I Use EPEL Repo?
You need to use YUM command for searching and installing packages. For example we search for Zabbix package using epel repo, lets see it is available or not under epel.
# yum --enablerepo=epel info zabbix
Sample Output
Available Packages
Name       : zabbix
Arch       : i386
Version    : 1.4.7
Release    : 1.el5
Size       : 1.7 M
Repo : epel
Summary    : Open-source monitoring solution for your IT infrastructure
URL        : http://www.zabbix.com/
License    : GPL
Description: ZABBIX is software that monitors numerous parameters of a network
Let’s install Zabbix package using epel repo option –enablerepo=epel switch.
# yum --enablerepo=epel install zabbix
Note: The epel configuration file is located under /etc/yum.repos.d/epel.repo.
This way you can install as many as high standard open source packages using EPEL repo