doc: add troubleshooting removal with --autoremove-ubuntu

This commit adds a troubleshooting article on removing ScyllaDB
with the --autoremove option.

Fixes https://github.com/scylladb/scylladb/issues/21408

Closes scylladb/scylladb#21697

docs/troubleshooting/autoremove-ubuntu.rst

@@ -0,0 +1,38 @@
+Removing ScyllaDB with the "--autoremove" option on Ubuntu breaks system packages
+======================================================================================
+
+Problem
+^^^^^^^
+
+Running ``apt purge scylla --autoremove`` marks most system packages for
+removal.
+
+.. code::
+
+   root@myserv:~# apt purge scylla --autoremove
+   Reading package lists... Done
+   Building dependency tree... Done
+   Reading state information... Done
+   The following packages will be REMOVED:
+     apport-symptoms* bc* bcache-tools* bolt* btrfs-progs* byobu* cloud-guest-utils* cloud-init* cloud-initramfs-copymods* cloud-initramfs-dyn-netconf* cryptsetup* cryptsetup-initramfs* dmeventd* eatmydata* ethtool* fdisk* fonts-ubuntu-console* fwupd* fwupd-signed* gdisk* gir1.2-packagekitglib-1.0* git* git-man* kpartx* landscape-common* libaio1* libappstream4* libatasmart4* libblockdev-crypto2* libblockdev-fs2*
+     libblockdev-loop2* libblockdev-part-err2* libblockdev-part2* libblockdev-swap2* libblockdev-utils2* libblockdev2* libdevmapper-event1.02.1* libeatmydata1* liberror-perl* libfdisk1* libfwupd2* libfwupdplugin5* libgcab-1.0-0* libgpgme11* libgstreamer1.0-0* libgusb2* libinih1* libintl-perl* libintl-xs-perl* libjcat1* libjson-glib-1.0-0* libjson-glib-1.0-common* liblvm2cmd2.03* libmbim-glib4* libmbim-proxy*
+     libmm-glib0* libmodule-find-perl* libmodule-scandeps-perl* libmspack0* libpackagekit-glib2-18* libparted-fs-resize0* libproc-processtable-perl* libqmi-glib5* libqmi-proxy* libsgutils2-2* libsmbios-c2* libsort-naturally-perl* libstemmer0d* libtcl8.6* libterm-readkey-perl* libudisks2-0* liburcu8* libutempter0* libvolume-key1* libxmlb2* libxmlsec1* libxmlsec1-openssl* libxslt1.1* lvm2* lxd-agent-loader* mdadm*
+     modemmanager* motd-news-config* multipath-tools* needrestart* open-vm-tools* overlayroot* packagekit* packagekit-tools* pastebinit* patch* pollinate* python3-apport* python3-certifi* python3-chardet* python3-configobj* python3-debconf* python3-debian* python3-json-pointer* python3-jsonpatch* python3-jsonschema* python3-magic* python3-newt* python3-packaging* python3-pexpect* python3-problem-report*
+     python3-ptyprocess* python3-pyrsistent* python3-requests* python3-software-properties* python3-systemd* python3-xkit* run-one* sbsigntool* screen* scylla* scylla-conf* scylla-cqlsh* scylla-kernel-conf* scylla-node-exporter* scylla-python3* scylla-server* secureboot-db* sg3-utils* sg3-utils-udev* software-properties-common* sosreport* tcl* tcl8.6* thin-provisioning-tools* tmux* ubuntu-drivers-common* udisks2*
+     unattended-upgrades* update-notifier-common* usb-modeswitch* usb-modeswitch-data* xfsprogs* zerofree*
+   0 upgraded, 0 newly installed, 139 to remove and 0 not upgraded.
+
+Cause
+^^^^^^^
+
+This problem may occur on Ubuntu 22.04 or earlier. It is caused by
+the ``systemd-coredump`` package installed with the ``scylla_setup`` script.
+Installing ``systemd-coredump`` results in removing ``apport`` and ``ubuntu-server``.
+In turn, the ``--autoremove`` option marks for removal all packages installed
+by ``ubuntu-server dependencies``.
+
+
+Solution
+^^^^^^^^^^
+
+Do not run the ``--autoremove`` option when removing ScyllaDB.

docs/troubleshooting/index.rst

@@ -14,6 +14,7 @@ Troubleshooting ScyllaDB
    storage/index
    CQL/index
    monitor/index
+   install-remove/index
 
 
 ScyllaDB's troubleshooting section contains articles which are targeted to pinpoint and answer problems with ScyllaDB. For broader issues and workarounds, consult the :doc:`Knowledge base </kb/index>`.
@@ -33,6 +34,7 @@ Keep your versions up-to-date. The two latest versions are supported. Also, alwa
   * :doc:`Data Storage and SSTables <storage/index>`
   * :doc:`CQL errors <CQL/index>`
   * :doc:`ScyllaDB Monitoring and ScyllaDB Manager <monitor/index>`
+  * :doc:`Installation and Removal <install-remove/index>`
 
 Also check out the `Monitoring lesson <https://university.scylladb.com/courses/scylla-operations/lessons/scylla-monitoring/>`_ on ScyllaDB University, which covers how to troubleshoot different issues when running a ScyllaDB cluster.
 

docs/troubleshooting/install-remove/index.rst

@@ -0,0 +1,13 @@
+Installation and Removal
+===========================
+
+.. toctree::
+   :hidden:
+   :maxdepth: 2 
+
+   Removing ScyllaDB on Ubuntu breaks system packages </troubleshooting/autoremove-ubuntu/>
+
+
+
+* :doc:`Removing ScyllaDB with the "--autoremove" option on Ubuntu breaks system packages </troubleshooting/autoremove-ubuntu/>`
+