Just a quick Reference for linux dedicated server administration

Basic Administration:

I got out of the initial release nearly as soon as I started using the server.
And have had a hard time working a lot of things out, so I just thought I share a few basic administration technics. Maybe, this will just be for myself. Maybe it will be of use for someone, one day.

Basic comands:
See what is going on with the machine:

Processes:
>> top
>> ps -aux

Space left on disks
>> df -h
-h is the option, which you tend to use to see the memory in human readable format
>> du -h –max-depth=1

you can move some folder from your /system/ partition to an other with more space by replacing the folder by a symbolic link. I am not sure this is best pratice, but if you run out of space, then this can be a life saving task.

Exemple:
>> mv /var/log /home/system/var/log ; ln -s /home/system/var/log /var/log

Virtual Memory
>> free

Server information
>> uname -a
>> hostname
>> ifconfig

Data manipulation

>> history | less

Finding data

>> which php
>> whereis php

Users and privileges:

>> chpwd
>> chown
>> chmod
>> chgrp

File Content:

>> cat filename | less
>> head filename
>> tail filename
>> vim filename

>> echo “whaterver you want to add” >> filename

Putting text in a file
>> history > filename.txt

Database:

>> mysql -h localhost -u username -p database_name < filename.sql
>> mysqldump -h localhsot -u username -p database_name –add-drop-table > filename.sql

Usefull queries:

database sizes:

SELECT table_schema "Data Base Name", sum( data_length + index_length) / 1024 / 1024
"Data Base Size in MB" FROM information_schema.TABLES GROUP BY table_schema ;

Archive:

unpack
>> tar xvfz archivename.tar.gz
pack
>> tar cvfz archivename.tar.gz folder1 folder2 …

But there is nothing really specific to gentoo here, and there is much more to linux administration than this. You should also find many much better manuals arround, which will cover this in much more detail.

Updating Hardware clock

Checking the time:
>> date

Checking the time on a time server:
>>htpdate -d -q www.linux.org www.freebsd.org