grub-install /dev/sda
grub-install –recheck /dev/sda
grub> device (hd0) /dev/sda
grub> root (hd0,0)
grub> setup (hd0)
grub-install /dev/sdagrub-install /dev/sda grub-install --recheck /dev/sda grub> device (hd0) /dev/sda grub> root (hd0,0) grub> setup (hd0)
Superblock general info
http://www.bellevuelinux.org/superblock
Convert to RAID 1
http://wiki.archlinux.org/index.php/Convert_a_single_drive_system_to_RAID
http://wiki.hpc.ufl.edu/index.php/System_mirror
http://www.howtoforge.com/software-raid1-grub-boot-debian-etch-p2
/bin/sh /usr/local/bin/els –mysqloptimizedb
mysqlcheck –optimize –repair –all-databases
Show all TCP connections, numeric (IP), process and app name, extended
netstat -antpe
Show all UDP connections, rest as above
netstat -anupe
Show all Unix, rest as above, full extended
netstat -anxpe
Crude DDoS test
netstat -an | grep ‘tcp\|udp’ | awk ‘{print $5}’ | cut -d: -f1 | uniq -c | sort -n
List listening and non-listening connections, numerical, TCP & UDP, extract the IP column, separate from port, count the occurances and finally sort numerically.
The config file (on FC) is /etc/pam.d/su.
One of the below lines must be uncommented
auth sufficient /lib/security//pam_wheel.so trust use_uid
auth required /lib/security//pam_wheel.so use_uid
Starts a process with a custom priority. The default “nice level” is 0.
Runs command with minimum priority (when noting else runs)
nice -n 20 command
Runs command with maximum priority
nice -n -19 command
Top a certain process by PID
top -p PID
Top a certain user
top -u user
f choose fields listed
o changes the display order
O change the sort by column
<> move sort field
R normal/reverse sorting
H show threads
c command name / full command line
i idle/running
S cumulative time
x highlight sort field
y highlight running threads
z toggle color/mone
b toggle highlight
u show specific user only
k send signal to a process
r renice a process
M sort by memory usage
P sort by CPU usage
d delay
W write config file
q quit
Lists all processes unde the form of a tree
Lists the structure in ASCII form (otherwise it’ll probably get listed in a nasty form)
pstree -A
By default the processes are listed in a compact form (i.e.: no threads). To disable this add -c
pstree -Ac
To display PID you need to add -p (also removes compaction)
pstree -Ap
To show command line arguments add -a
pstree -Aa
Numeric sort
pstree -An
