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centos linux

Red Hat / CentOS Linux Install Cluster Suite Software

Q. How do I install Cluster Suite software on CentOS Linux 5 IBM server for testing purpose?
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How do I know When I Need To Update My Linux System Software?

Q. How do I know when I need to update my Linux system? How do I know new patches are available for CentOS Linux (Red Hat) / Debian Linux server system?
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Linux: ifdown eth0:0 brings down all other virtual network interfaces

Q. Why do the other virtual network interfaces go down when I bring down eth0:0 under CentOS Linux?
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yum command: Update / Install Packages Under Redhat Enterprise / CentOS Linux Version 5.x

How do I use yum command to update and patch my Red hat Enterprise Linux / CentOS Linux version 5.x server via RHN / Internet? Can I use up2date command under RHEL 5?
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Red hat / Fedora / CentOS Yum Repo is Listed More Than Once

Q. Why does my yum command fail with an error that a repo is listed more than once under Fedora / RHEL / CentOS Linux? This error occurs when I type yum clean command

Loading “rhnplugin” plugin
Loading “security” plugin

Repository xen-repo is listed more than once in the configuration

How do I fix this problem?

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Linux Virtual Network Interfaces Go Down When I bring Down eth0:0

Q. My RHEL / CentOS Linux 4.x virtual network interfaces go down when I bring down eth0:0. How do I fix this issue?
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RHEL / CentOS Linux FTP Cron Job for automatic ftp backup

I need help with a cron job. A automatic ftp backup will pickup sql.tar.gz and upload to remote ftp server under CentOS Linux. How do I automate entire procedure to upload file /tmp/backup/sql.tar.gz?
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Red Hat / CentOS Linux Setting a Default Gateway

Q. How do I setup up a default Gateway for all interfaces (eth0 and eth1) under CentOS Linux 5?

A.There are different ways to setup TCP/IP hosts so that you can reach to remote destinations. The simplest one is to setup default gateway by modifying the /etc/sysconfig/network

Setup a default Gateway

Open /etc/sysconfig/network file:
# vi /etc/sysconfig/network
Setup GATEWAY={Router-IP}, if router IP is, type:
Save and close the file. Here is my complete file:

You need to restart networking service:
# /etc/init.d/networking restart

Linux list all IROs currently in use

Q. How do I list all IRQs currently used under CentOS Linux?

A.. There is a file called /proc/interrupts. The proc filesystem is a pseudo filesystem which is used as an interface to kernel data structures. It is commonly mounted at /proc.

This is used to record the number of interrupts per each IRQ on (at least) the i386 architecture. Very easy to read formatting, done in ASCII.

Display /proc/interrupts

Use cat or less command:
$ cat /proc/interrupts

           CPU0       CPU1       CPU2       CPU3       
  0:        187          0          0          0   IO-APIC-edge      timer
  1:      39922          0          0          0   IO-APIC-edge      i8042
  7:          0          0          0          0   IO-APIC-edge      parport0
  8:          4          0          0          0   IO-APIC-edge      rtc
  9:          1          0          0          0   IO-APIC-fasteoi   acpi
 12:     846774          0          0          0   IO-APIC-edge      i8042
 14:     105048          0          0          0   IO-APIC-edge      libata
 15:          0          0          0          0   IO-APIC-edge      libata
 16:    1069722          0          0          0   IO-APIC-fasteoi   libata, uhci_hcd:usb4, nvidia
 17:     105382          0          0          0   IO-APIC-fasteoi   eth0
 18:      83040          0          0          0   IO-APIC-fasteoi   uhci_hcd:usb2, libata
 19:          0          0          0          0   IO-APIC-fasteoi   uhci_hcd:usb1, ehci_hcd:usb5
 20:     474168          0          0          0   IO-APIC-fasteoi   uhci_hcd:usb3, ohci1394, ra0
 21:      10117          0          0          0   IO-APIC-fasteoi   bttv0
 22:     594327          0          0          0   IO-APIC-fasteoi   HDA Intel
NMI:          0          0          0          0 
LOC:    1754492    1545836    2085855    1878596 
ERR:          0
MIS:          0

CentOS Linux apply package updates

Q. I’ve CentOS Linux 5 Server and I’d like to apply all package and security update. How do I apply package updates from the Internet?

A. CentOS comes with yum command. It is a command-line interface to update packages. There is also a graphical tool called pup.

yum command

For a command-line interface over the ssh session, the the command as root user:
# yum update

pup command

To start the graphical Update tool, type the command:
# pup &