Administration & Server Software

• 1 Being 'root'
• 2 Backup
• 3 Emergency Recovery
• 4 Managing Processes
• 5 Mounting
• 6 Scheduling
• 7 System Services
• 8 Getting Organized
  • 8.1 Config files
• 9 Bash Aliases

Being 'root'

'root' is the most powerful account on a Linux system. Learn how to use it wisely and appropriately.

• Introducing 'root'
• Using 'root' Considered Harmful
• Tasks Which Require 'root' Privileges
• Becoming 'root' With 'su'
• 'su' Going Graphical: 'kdesu'
• 'su' Made Convenient: 'sudo'

Backup

You should backup your personal files on a regular basis. Usually, each user saves his personal files in the user directory under the /home directory. All the global administrative configuration files are stored in /etc and can be written only by the root user.

Tools for backup are:

• tar command
• dd (device dump) command
• partimage … save whole partitions of Ext2FS, ReiserFS, NTFS and FAT32 - This is very useful when installing the same software on many machines: just install one of them, create an image, and just restore the image on all other machines. Then, after the first one, each installation is automatically made, and only require a few minutes.

Emergency Recovery

How to cope with severe system errors.

• Rescue vs Reinstalling
• Basic Rescue Tools
• The Mandrake Linux Rescue System
• Booting 'failsafe'
• Single User Mode
• The root Shell
• Linux Systems On Other Media
• Scenario I: System Doesn't Boot
• Scenario II: System Stops During Boot
• Scenario III: Login Fails
• Scenario IV: System Hangs On Loading X
• Scenario V: System Freeze
• Scenario VI: Important Files Deleted

Managing Processes

Almost everything going on in Linux is a process. Have a look at what they are and how to manage them.

• Introducing Processes
• Process Monitors
• Processes In Detail
• Process Accounting
• Estimating Process Resource Usage
• Setting Resource Limits
• Dealing With Bad Processes

Mounting

How to handle file systems in Linux.

• Why Linux Handles Media Differently
• Default mount Setup In Mandrake Linux
• Mounting In Detail
• Writing Windows NTFS
• Uses Of 'fstab'
• 'fstab' Entries explained
• Using 'supermount'
• "maximal mount count reached - check forced"
• "device was not cleanly unmounted on shutdown - check forced"
• "mount: only root can do that"
• CD-Rom Tray Is Blocked
• 'df' doesn't list external media anymore
• "mount: can't find /mnt/{device} in /etc/fstab or /etc/mtab"
• '{device} is not a valid blockdevice'
• Audio CDs Don't Play When Mounted
• "input/output error"
• No Proper Unmounting ('Device Busy')
• No User Access To Files On Mounted Windows Partitions
• Trouble Mounting Removable Media With Different File Systems
• Preparations
• Creating Mount Points
• Configuring autofs Files In /etc
• Desktop Icons For Easy Access

Scheduling

How to tell your computer to do certain things at a certain time.

• What Scheduling Can Do
• 'sleep', 'at', 'cron' and 'anacron'
• 'sleep'
• 'at'
• Specifying Execution Time
• Writing Your Own Crontab
• Example: Monthly Compression Of 'sent_mail' Folder
  
• anacron
• Interactive Schedulers

System Services

System services: what they are and how to control them.

• Introducing System Services
• Advantages Of The Service Mechanism
• DrakXServices
• How Services Work
• Annotated List of Common Services (a-h)
• Annotated List of Common Services (i-n)
• Annotated List of Common Services (o-y)
• Deprecated Services

Getting Organized

Config files

For example, as root:

mkdir /root/config
cd /root/config
mkdir samba apache dns network cups sasl rsynccd samba
ln -s /etc/samba/smb.conf
ln -s /etc/samba/smbusers
ln -s /etc/lmhostscd /root/config/apache
ln -s /etc/httpd/conf/httpd2.conf
ln -s /etc/httpd/conf/commonhttpd.conf
ln -s /etc/httpd/conf/vhosts/Vhosts.confcd /root/config/dns
ln -s /etc/hosts
ln -s /etc/resolv.conf
ln -s /var/named/named.ca
ln -s /etc/named.conf
ln -s /etc/networks
ln -s /var/named/localhostcd /root/config/network
ln -s /etc/sysconfig/network-scripts/ifcfg-eth0
ln -s /etc/sysconfig/network-scripts/ifcfg-eth1
ln -s /etc/services

Now everything will be in one place the next time you configure a service. If you use an editor that creates backup files, with the '~~' suffix, you won't have them all over your filesystems.

Bash Aliases

tail /var/log/syslog

less /var/log/messages

alias tslog='/usr/bin/tail /var/log/syslog'
alias lslog='/usr/bin/less /var/log/syslog'
alias tmsg='/usr/bin/tail /var/log/messages'
alias lmsg='/usr/bin/less /var/log/messages'
alias tauth='/usr/bin/tail /var/log/auth.log'
alias lauth='/usr/bin/less /var/log/auth.log'
alias tmail='/usr/bin/tail /var/log/mail/info'
alias lmail='/usr/bin/less /var/log/mail/info'
alias tkern='/usr/bin/tail /var/log/kernel/info'
alias lkern='/usr/bin/less /var/log/kernel/info'
alias thacc='/usr/bin/tail /var/log/httpd/access_log'
alias lhacc='/usr/bin/less /var/log/httpd/access_log'
alias therr='/usr/bin/tail /var/log/httpd/error_log'
alias lherr='/usr/bin/less /var/log/httpd/error_log'
alias thsacc='/usr/bin/tail /var/log/httpd/ssl-access_log'
alias lhsacc='/usr/bin/less /var/log/httpd/ssl-access_log'
alias thserr='/usr/bin/tail /var/log/httpd/ssl-error_log'
alias lhserr='/usr/bin/less /var/log/httpd/ssl-error_log'
alias tsmb='/usr/bin/tail /var/log/samba/log.smbd'
alias lsmb='/usr/bin/less /var/log/samba/log.smbd'
alias tnmb='/usr/bin/tail /var/log/samba/log.nmbd'
alias lnmb='/usr/bin/less /var/log/samba/log.nmbd'
alias urpmi='nice -n 15 urpmi ––split-level 10 ––split-length 8'
alias rpm='nice -n 15 rpm'
alias make='nice -n 16 make'

These aliases will become new commands the next time you login. If you can't wait, type each one at the command prompt so they will also be availble in your current login session. Learn these new commands and system administration will be easier.