Monthly Archives: July 2010 - Page 3

Proc Info

System Info – procinfo
procinfo gathers some system data from the /proc directory and prints it formatted on the screen.

Some of the information displayed is

Last Boot time
Load Average
average number of jobs running
number of runnable processes
total number of processes
PID of the last process run (idem)
Swap info
Memory resources
Number of disks
IRQ info
Installed modules (with the -a or -m option)
File Systems (with the -a or -m option)
To automatically update the displayed info every 30 seconds

yum install procinfo

procinfo -fn30

Free up some memory with DROP Cache

sync; echo 3 > /proc/sys/vm/drop_caches

Writing to this will cause the kernel to drop clean caches, dentries and inodes from memory, causing that memory to become free.
This is a non-destructive operation, and dirty objects are not freeable, the user should run “sync” first in order to make sure all cached objects are freed

Change the default editor for Crontab

export EDITOR=nano

Install the virtual viewer a VNC Client

Install the Virtual Viewer VNC Client
yum install virt-viewer




Disable root logins

edit the setting in the ssh config found at /etc/ssh/sshd_config
PermitRootLogin no

then restrict the users that can log in using ssh, use spaces between names
AllowUsers alice bob

restrart sshd service
service sshd restart

Basic Hardening Prinicples


Mail server install

Linux system commands


yum install webalizer
for i in /etc/webalizer/*.conf; do webalizer -c $i; done

Directory Commands

Size of disk

df -h