log a command to console and to 2 files separately stdout and stderr

# command > >(tee stdout.log) 2> >(tee stderr.log >&2)
_____

Real full backup copy of /etc folder
# rsync -a /etc /destination

If your repository is available on a server for e.g. 10.10.10.6, you need to point it to that server in your config file.

# cat /etc/yum.repos.d/rhel.repo
[base]
name=RHEL 5 $releasever - $basearch - Base
baseurl=http://10.10.10.6/yum/rhel/5/base/
enabled=1
gpgcheck=0

If the internet is not working from a server, you need to change one file.

cat /etc/resolove.conf

nameserver 8.8.8.8
nameserver 10.10.10.1
nameserver 10.10.10.6

/etc/init.d/network restart

The mail command will not work if the internet is down.

Download and Install redis from http://www.redis.io/download or use the following commands on the target server.

$ wget http://redis.googlecode.com/files/redis-2.2.8.tar.gz
$ tar xzf redis-2.2.8.tar.gz
$ cd redis-2.2.8
$ make

Start the redis server. To start the redis server please use the following command
$src/redis-server

configure the redis server ip in the Java properties file (cache.server) and ip (cache.port). The default port is 6379.

Important things to remember about Linux date:

* /etc/sysconfig/clock sets whether the hardware clock is stored as UTC or local time.
* Symlink /etc/localtime to /usr/share/zoneinfo/... to set your timezone.
* Run ``date MMDDhhmm'' to set the current system date/time.
* Type ``/sbin/hwclock --systohc [--utc]'' to set the hardware clock.

// copy the file to RAM - 30 times faster
cp -af /root/100mb.bin /dev/shm/

// increase it to 4GB
mount -o remount,size=4G /dev/shm

// new memory device
mkdir -p /var/www/www.mysite.com/ramdrive
mount -t tmpfs -o size=500M,mode=0744 tmpfs /var/www/www.mysite.com/ramdrive

// add it to /etc/fstab to make it permanent:
tmpfs /var/www/www.mysite.com/ramdrive tmpfs size=500M,mode=0777 0 0

660 mysql data dir
700 home directory
777 world writeable files
chmod +x asper.sh OR (chmod 754 asper.sh)

You can save the current file as a new file after making changes,
:w new_file.txt

If you want only 50 lines starting from line number 100, use...
:100,150w! new_file.txt

ps aux
When you run ps you will only get the first 40 or so characters displayed. In order to view the entire string, use ...
ps auxgww

If you're a Linux expert, Fedora is for you. If you just want a good, general-purpose desktop for home or work, then openSUSE is your best pick. And if you're new to Linux, and your computer gets along well with Ubuntu, Ubuntu is still a good choice.
Knoppix if you want to use Linux off a live CD and puppy linux is for everyone!!