check hard disk rpm or rotation speed

Lot of times you want to check the disk rpm, especially on the servers to check if it is 7.2K or 10K or 15K rpm disk. How do you do this from linux terminal. Here it is :

sginfo -g /dev/<device>

Note that sginfo comes from sg3-utils.

ssh trick – ssh to remote host with bastion host

Lot of times, you have to ssh to a server with bastion host. If you dont know what is bastion host then see this:

Now, in such cases, either you add an entry in “~/.ssh/config” to route the ssh through the bastion host or do ssh to bastion host and then ssh from there to the actual host. But wait, there is always a better way:

terminal.sexy for URxvt

Sometime back I posted about terminal.sexy – make your teminal sexy. I personally use URxvt terminal and hence need the xrdb files to apply the theme. It’s pain to go to the website everytime I want to change my theme and hence I wrote a python script that can use the github repo and convert the files to xrdb files. Here is the link to the script:
terminal.sexy script for xrdb

Color schemes for your terminal

Color Scheme for Gnome Terminal and Pantheon Terminal – here is the github page

https://github.com/Mayccoll/Gogh/

Check your session type – wayland or X11

With both wayland and X11 in mainstream, its pretty easy to forget if you are running in Wayland or in X11. To check this here are the commands:

loginctl list-sessions
# The above command will show you all the sessions. Note the session number for your session

loginctl show-session <session number> -p Type

Split pcap to multiple files based on number of packets

Here is a script that can use tshark to split a large pcap to multiple small pcaps

inpcap="test.pcap"

max=$(tshark  -r $inpcap -n -T fields -e frame.number|tail -1)

# This is the number of packets in each split pcap
c=1

# Save all new pcaps to out, if it does not exist, create it.
[[ ! -d out ]] && mkdir out

for i in $(seq 1 $max $c)
do
        tshark  -r $inpcap  -n -c $c "frame.number==$i" -w out/$i.pcap
        #Do other stuff, if required
        read -p "Send the next packet? "
done

A very simple 3-4 line script that has saved my day so may times.

libvirt- Create virtual machine with text console only interface

virt-install is an amazing tool to create VMs. If you have created a config file (Kickstart file – ks.cfg), then its only one line un-attended install. If you are using this on remote host with ssh and unluckily cannot export display – what do you do. Do a non-graphical install. There are only minor changes in the command to tell the installer that there is no graphics available and it is amazing, is it not 🙂