After updating today, I obviously ran out of /boot space:
 [✓] Syncing filesystems                                                success
 [✓] Updating dynamic library cache                                     success
 [✗] Updating clr-boot-manager                                           failed
A copy of the command output follows:
[FATAL] cbm (../src/bootman/kernel.c:L668): Failed to install initrd /boot/initrd-com.solus-project.current.5.10.9-169: No space left on device
[FATAL] cbm (../src/bootman/update.c:L250): Failed to install default-current kernel: ///usr/lib/kernel/com.solus-project.current.5.10.9-169
 [✓] Running depmod on kernel 4.14.216-165.lts                          success
 [✓] Running depmod on kernel 5.10.9-169.current                        success
 [✓] Updating system users                                              success
 [✓] Updating systemd tmpfiles                                          success
 [✓] Reloading systemd configuration                                    success
 [✓] Re-starting vendor-enabled .socket units                           success
 [✓] Restarting VirtualBox services                                     success
 [✓] Compiling glib-schemas                                             success
 [✓] Updating mimetype database                                         success
 [✓] Updating icon theme cache: hicolor                                 success
 [✓] Updating icon theme cache: Papirus-Dark                            success
 [✓] Updating icon theme cache: Papirus-Adapta-Nokto                    success
 [✓] Updating icon theme cache: Papirus-Adapta                          success
 [✓] Updating icon theme cache: solus-sc                                success
 [✓] Updating icon theme cache: Papirus                                 success
 [✓] Updating icon theme cache: Papirus-Light                           success
 [✓] Updating desktop database                                          success
 [✓] Updating manpages database                                         success
 [✓] Reloading udev rules                                               success
 [✓] Applying udev rules                                                success
sudo clr-boot-manager list-kernels
  com.solus-project.current.5.10.9-169
  com.solus-project.current.5.10.7-168
  com.solus-project.current.5.10.5-167
  com.solus-project.lts.4.14.216-165
  com.solus-project.lts.4.14.215-164
  com.solus-project.lts.4.9.205-147
ls -l /boot/
total 209924
-rw-r--r-- 1 root root  8029888  9. Jan 23:40 com.solus-project.current.5.10.5-167
-rw-r--r-- 1 root root  8189088 16. Jan 16:43 com.solus-project.current.5.10.7-168
-rw-r--r-- 1 root root  8190272 23. Jan 17:13 com.solus-project.current.5.10.9-169
-rw-r--r-- 1 root root  9905664 16. Jan 16:43 com.solus-project.lts.4.14.215-164
-rw-r--r-- 1 root root  9913856 23. Jan 17:13 com.solus-project.lts.4.14.216-165
-rw-r--r-- 1 root root  7935072  6. Dez 2019  com.solus-project.lts.4.9.205-147
drwxr-xr-x 5 root root     1024 16. Jan 16:43 grub
-rw-r--r-- 1 root root 31583025  9. Jan 23:40 initrd-com.solus-project.current.5.10.5-167
-rw-r--r-- 1 root root 31926467 16. Jan 16:43 initrd-com.solus-project.current.5.10.7-168
-rw-r--r-- 1 root root 30600775 16. Jan 16:43 initrd-com.solus-project.lts.4.14.215-164
-rw-r--r-- 1 root root 42406395 23. Jan 17:13 initrd-com.solus-project.lts.4.14.216-165
-rw-r--r-- 1 root root 26262160  6. Dez 2019  initrd-com.solus-project.lts.4.9.205-147
drwx------ 2 root root    12288 25. Apr 2019  lost+found
I'm afraid to reboot now. How can I remove older kernels that are taking up space and repair the installation?
Can I just delete the older com.solus-project and initrd-com.solus-project files on /boot and run "sudo clr-boot-manager update"?
I found https://discuss.getsol.us/d/4023-updating-clr-boot-manager-failed-no-space-left but the solution discussed there is about EFI and extending the partition.