psql -U postgres template1

psql: FATAL: Ident authentication failed for user “postgres”

Explanation:- access permission in /var/lib/pgsql/data/pg_hba.conf
this problem was solved by editing ” /var/lib/pgsql/data/pg_hba.conf” file
This file decide how the host are allowed to connect  and which databases they can use.

Modify the entry as this

local   all         all                              trust

host    all         all         127.0.0.1/32         trust

yum clean all
yum makecache
yum update

Some screen  commands to remember

• screen -ls will list the current screen sessions running on a machine.
• Control+a (press Control and then press a) Will toggle between your current shell and your previous shell
• Control+a d will detach you from a session.

Basics of how to use screen on a Linux/Ubuntu machine

Create a session :-
screen -S sessionname
Here I am giving  “screen -S nuxeo” //I am working on nuxeo , so I named it

We can have up to 10 interactive shells open in one window.When we start a new session we are in shell 0.
To create more shells,Press cntrl key, then press and release  the “a” key and type letter “c”

switching between shells
press ctrl, then press and relase “a”  key and then press the shell no

GNU Screen allows you to manage several interactive shell instances within the same “window.” By using different keyboard shortcuts, you are able to shuffle through the shell instances, access any of them directly, create new ones, kill old ones, attach and detach existing ones.

Instead of opening up several terminal instances on your desktop or using those ugly GNOME/KDE-based tabs, Screen can do it better and simpler.

Not only that, with GNU Screen, you can share sessions with others and detach/attach terminal sessions. It is a great tool for people who have to share working environments between work and home.

if running

give vncserver :desktopno

ie vncserver: 1

now  you will be able to use ur client remote desktop to connect to the centos

It was because by default JBossAS binds its services to localhost (127.0.0.1) *by default*, instead of binding to all available interfaces (0.0.0.0). This was primarily done for security reasons because of concerns of users going to production without having secured their servers properly.

We can enable it by running “/opt/nuxeo-dm/bin/run.sh -b 0.0.0.0 “

lspci    =    Which list all PCI devices

lshw    =    List hardware

lshw -C network  = List device which are under group network

To find PCI devices , let us say network

lspci -v | grep Ethernet -A 1

18:00.0 Ethernet controller: Broadcom Corporation NetLink BCM5787M Gigabit Ethernet PCI Express (rev 02)
Subsystem: Hewlett-Packard Company Device 30c0

##

To find the  info about network devices

it is “ifconfig”

$du -ch | grep total
This would have only one line in its output that displays the total size of the current directory including all the subdirectories.

$du –exculde=doc
The above command would display the size of the current directory along with all its subdirectories, but it would exclude all the files having the given pattern present in their filenames. Thus in the above case if there happens to be any doc files within the current directory or any of its subdirectories, their size would not be included while calculating the total directory size.

$du -ch | sort -rn
Listing the disk space used for a directory and its subdirectories, sorted by disk usage

When SQUID was used for internet sharing in All MS enviornment  respone was :- It is only in the server side , and It is not doing much other than internet sharing.

When using CVS . Explanation was was:-  It is only in the version control
When using Linux OS for ORACLE erp . Explanation Oracle works well with Linux
When SAMBA was used for PDC. Explanation was was:-  It is only in the server side
When Nagious /ZABBIX was used.   Explanation was was:-  It is only for monitoring
When SNORT  was used. Explanation was :-  It is only for IDS
When OpenVPN was used. Explanation was :-  It is only for VPN
When ISPConfig was used. Explanation was :-  It is only for Web Site management
when Joomla was used. Explanation was :-  It is only for Web Site hosting
When Asterisk was used . Explanation was :-  It is only for Phone system

When DOTproject was used. Explanation was :-  It is only for Project Management

When UltraMonkey was used. Explanation was :-  It is only for Load Balancing

When heartbeat was used.  Explanation was :-  It is only for High Avaliablity

When Amanda/BackuPC was used. Explanation was :-  It is only  for BackupWhen
When Nuxeo was introduced[Not used live so far] :- It is only for DM

“update-rc.d -f  service remove ” to disable the services when the machine boots up