Category Archives: Linux

Remove the ABCD– prefix from a filename:$ s=’ABCD –11212239.pdf’$ mv “$s” “${s#ABCD–}” Remove the prefix from all files in current directory recursively:while IFS= read -r -d ” filename; do mv “$filename” “${filename#ABCD–}”done < <(find . -type f -name ‘ABCD–*’ -print0) … Continue reading →

#Check size of Volume Groupdf -h -T | grep vg#Display volume group info. Check for free spacesudo vgdisplay#Display logical volume infosudo lvdisplay#Test runsudo lvextend -t -v -l +100%FREE /dev/ubuntu-vg/ubuntu-lv#Actual runsudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv#Resize logical volumesudo resize2fs /dev/ubuntu-vg/ubuntu-lv#Verifydf -h -T … Continue reading →

To boot into single user mode from the Grub menu: In Ubuntu, the Grub Menu should appear if you press and hold Shift while Grub is loading, if you boot using BIOS. If your Ubuntu system boots using UEFI, press Esc instead. You … Continue reading →

Calculate MySQL Memory Usage – Quick Stored Procedure

To see what systems on the 192.168.11.0 network are listening on port 22:nmap -sV -p 22 192.168.11.0/24 To do an nmap ping scan on 192.168.11.0 network:nmap -sp 192.168.11.0/24 To scan the top five ports on 192.168.11.7:nmap –top-ports 5 192.168.11.7

Use the Linux Standard Base command as follows:lsb__release -a

The du command is very useful when you are looking at disk space usage. Here are some of the most commonly used parameters: -h human-readable Displays sizes in human-readable format, using units such as KB, MB, GB, etc-a, –all Lists … Continue reading →

#Run iostat to get the average cpu usage every 10 seconds for 10 times:iostat -x 10 10 >> /home/<user>/iostat.out.$(date +”%Y-%m-%d”) #Run dstat to get cpu stats for cpus 1, 3 and the total:dstat -C 0,3,total

top and htop are free CLI process viewers. They list the top resource using processes being run.The information includes: top options:–a : Sort by memory usage This switch makes top to sort the processes by allocated memory–d : Delay time update interval as: -d ss.tt (seconds.tenths)–p : Monitor PIDs as: -pN1 … Continue reading →