Comment # 20 on bug 1195291 from Ulrich Windl

Well, SUSE introduced the problem quickly, but takes a lot of time to fix it.
Meanwhile users suffer:
After having updated the kernel, I had to wait almost 5 minutes until I could
log in after boot. That's almost as slow as booting Windows.

# systemd-analyze 
Startup finished in 813ms (kernel) + 13.472s (initrd) + 4min 1.948s (userspace)
= 4min 16.234s 
graphical.target reached after 4min 1.908s in userspace
# systemd-analyze blame 
3min 41.865s plymouth-quit-wait.service
3min 29.156s purge-kernels.service
     27.809s mandb.service
...
         9ms dracut-pre-pivot.service
         8ms dracut-pre-mount.service
         4ms initrd-udevadm-cleanup-db.service
         1ms sys-fs-fuse-connections.mount
         1ms sys-kernel-config.mount

Summary from /var/log/zypp/history:
2023-01-28 17:31:44|command|root@i7g4x4a|'/usr/bin/zypper' '-n'
'purge-kernels'|
2023-01-28 17:32:30|remove
|kernel-default-devel|5.14.21-150400.24.33.2|x86_64|root@pc|
# 2023-01-28 17:33:38 kernel-default-optional-5.14.21-150400.24.33.2.x86_64
removed ok
2023-01-28 17:33:38|remove
|kernel-default-optional|5.14.21-150400.24.33.2|x86_64||
2023-01-28 17:33:54|remove |kernel-devel|5.14.21-150400.24.33.1|noarch|root@pc|
# 2023-01-28 17:34:21 kernel-default-extra-5.14.21-150400.24.33.2.x86_64
removed ok
2023-01-28 17:34:21|remove
|kernel-default-extra|5.14.21-150400.24.33.2|x86_64||
2023-01-28 17:35:02|remove
|kernel-default|5.14.21-150400.24.33.2|x86_64|root@pc|

So that's three rebuilds of the initrd when removing the packages for _one_
kernel version!
(Related to comment #6: It seems bootloader was reconfigured only one, so the
os-prober is not the biggest contributor)
How does Fedora manage it to make only one rebuild of the initrd at the end?
Maybe have a look!

In version before the bug, kernel removal took place in the background at
least, and the user was able to start working while kernels were removed.