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--- packages:remove_kernels [2016/07/04 00:06] – peter
+++ packages:remove_kernels [2019/12/01 12:03] (current) – removed peter
@@ Line 1: / Line 1: @@
-====== Packages - Removed Unused Kernels ======
-Ubuntu does not remove kernels when they install a new one, however the /boot partition is usually relatively small.  So after only a few kernel upgrades, you can get **No Space Left On Device** errors when trying to upgrade.
-To determine which kernels can be removed run the following:
-<code>
-dpkg --get-selections | grep 'linux-image.*-[0-9].*' | awk '{print $1}' | egrep -v "$(uname -r)"| while read n; do echo $n; done
-</code>
-To delete all these old kernels run the following.
-**NOTE**:  This will only keep the very latest kernel and will delete all others, so may not be what you want:
-<code>
-dpkg --get-selections | grep 'linux-image.*-[0-9].*' | awk '{print $1}' | egrep -v "$(uname -r)"| while read n; do apt-get -y remove $n; done
-</code>
-===== Another Method =====
-Either remove them manually, or use this one liner to automatically remove them all.
-<code>
-export KERNEL="$(uname -r | grep -Po '([0-9\.\-]*[0-9])?')"; dpkg --get-selections | grep -E "linux-(header|image).*" | grep -iw install | sort | grep -v "$KERNEL" | grep -v "lts" | sed 's/install//g' | xargs dpkg -P
-</code>
-Here's the command by command explanation:
-<code>
-export KERNEL="$(uname -r | grep -Po '([0-9\.\-]*[0-9])?')"
-</code>
-The first portion sets the current kernel number in a variable KERNEL.  It only takes the number, and greps out any additions like -generic or -server.
-<code>
-dpkg --get-selections
-</code>
-The second portion first prints out all available packages.
-<code>
-grep -E "linux-(header|image).*"
-</code>
-The third portion greps for all packages with either linux-header or linux-image in the name.
-<code>
-grep -iw install
-</code>
-The fourth portion greps out only installed packages.
-<code>
-sort
-</code>
-The fifth portion sorts the output.
-<code>
-grep -v "$KERNEL" | grep -v "lts"
-</code>
-The sixth portion filters out the current kernel and the LTS kernel package.  Removing those will cause problems.
-<code>
-sed 's/install//g'
-</code>
-The seventh part strips off the install part.
-<code>
-xargs dpkg -P
-</code>
-The last part actually removes the packages.  **xargs** send all the package names to **dpkg**.  Then **dpkg -P** purges the packages.  That means, removing them and removing their configs.