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.
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:
Continue readingWith 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
Here is a good link to do this:
https://fedoramagazine.org/using-the-networkmanagers-dnsmasq-plugin/
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.
Continue readingOther day, I was trying to copy the proc folder with following command:
tar cvzf /tmp/proc.tgz /proc
and I found out that all the files in tar were empty. Strange it may seem but lot of people are facing this as /proc is not a regular filesystem, so I wrote a quick script to copy the proc folder. Here is the script:
cd /
mkdir /tmp/proc
[[ -z $1 ]] && exit -1
find /proc/$1/ -not -name pagemap | while read F ; do
D=/tmp/$F
if [[ -d $F ]]
then
echo "$(ls -ld $F) => Directory"
mkdir -p $D
fi
if [[ -L $F ]]
then
echo "$(ls -ld $F) => copied"
cp -P $F /tmp/$F
elif [[ -f $F ]]
then
echo "$(ls -ld $F) => Cat"
cat $F > /tmp/$F
else
echo "Dont know $F"
fi
done
I generallly keep doing this a lot, so thought will share with you. Lets assume we are capturing free ouput every min/hour/or whatever. The output looks like this:
Time: Mon Jan 21 23:59:10 AEDT 2019
——————-total used free shared buff/cache available
Mem: 32014 8656 1735 1697 21621 21308
Swap: 51195 75 51120
then we can use some grep and sed to convert this to something like this:
Mon Jan 21 23:59:10 AEDT 2019,32014,8656,1735,1697,21621,21308
Continue reading