Comment 2 for bug 1901395

Currently I have:

```
$ ls /boot/ --human-readable -lt
total 103M
-rw-r--r-- 1 root root 86M окт 25 12:43 initrd.img-5.4.0-52-generic
drwxr-xr-x 6 root root 1,0K окт 25 12:42 grub
lrwxrwxrwx 1 root root 27 окт 25 11:56 initrd.img.old -> initrd.img-5.4.0-52-generic
lrwxrwxrwx 1 root root 24 окт 25 11:56 vmlinuz.old -> vmlinuz-5.4.0-52-generic
lrwxrwxrwx 1 root root 27 окт 25 02:41 initrd.img -> initrd.img-5.4.0-52-generic
lrwxrwxrwx 1 root root 24 окт 25 02:41 vmlinuz -> vmlinuz-5.4.0-52-generic
drwx------ 2 root root 12K окт 24 16:18 lost+found
-rw------- 1 root root 12M окт 15 13:33 vmlinuz-5.4.0-52-generic
-rw-r--r-- 1 root root 233K окт 15 13:28 config-5.4.0-52-generic
-rw------- 1 root root 4,6M окт 15 13:28 System.map-5.4.0-52-generic
-rw-r--r-- 1 root root 179K авг 18 13:46 memtest86+.bin
-rw-r--r-- 1 root root 181K авг 18 13:46 memtest86+.elf
-rw-r--r-- 1 root root 181K авг 18 13:46 memtest86+_multiboot.bin

$ sudo du -sh /boot/
110M /boot/
```

Setting xz compression:

```
$ cat /etc/initramfs-tools/initramfs.conf | grep COMPRESS
# COMPRESS: [ gzip | bzip2 | lz4 | lzma | lzop | xz ]
COMPRESS=xz
```

does not help either.

Even removal of the all contents of /boot folder does not help:

```
The upgrade has aborted. The upgrade needs a total of 238 M free
space on disk '/boot'. Please free at least an additional 13,5 M of
disk space on '/boot'. You can remove old kernels using 'sudo apt
autoremove' and you could also set COMPRESS=xz in
/etc/initramfs-tools/initramfs.conf to reduce the size of your
initramfs.

```

You have to take such scenarios into account.