linux devices and sync

bash.sh

# to detach a busy device immediately
umount -l /PATH/OF/BUSY-DEVICE
umount -f /PATH/OF/BUSY-NFS(NETWORK-FILE-SYSTEM)

# locate/identify the busy the process
lsof | grep '/dev/sda1'
pkill target_process
umount /dev/sda1

# kill any processes accessing file
fuser -kim /address
unmount /address

# sync two folders
# -a Do the sync preserving all filesystem attributes
# -v run verbosely
# -u skip files that are newer on the receiver
# --delete delete the files in target folder that do not exist in the source, /home/user/A: source folder, /home/user/B: target folder
rsync -avu --delete "/home/user/A" "/home/user/B"

# format partition
sudo mkfs.ext4 /dev/sdaX

# check attached devices
lsblk
lsblk --fs

# remove all metadata from mp4 file
ffmpeg -i test.mp4 -map_metadata -1 -c:v copy -c:a copy out.mp4