remove old kernels ubuntu 20.04
create a file named remove_old_kernels.sh
add this text in the file :
```
#!/bin/bash
# Run this script without any param for a dry run
# Run the script with root and with exec param for removing old kernels after checking
# the list printed in the dry run
uname -a
IN_USE=$(uname -a | awk '{ print $3 }')
echo "Your in use kernel is $IN_USE"
OLD_KERNELS=$(
dpkg --list |
grep -v "$IN_USE" |
grep -Ei 'linux-image|linux-headers|linux-modules' |
awk '{ print $2 }'
)
echo "Old Kernels to be removed:"
echo "$OLD_KERNELS"
if [ "$1" == "exec" ]; then
for PACKAGE in $OLD_KERNELS; do
yes | apt purge "$PACKAGE"
done
fi
```
Run it like this for a dry run:
```
remove_old_kernels.sh
```
If all looks good, run it again like this:
```
sudo remove_old_kernels.sh exec
```