Today, when I restart a failed server, stuck inLoading module ipmi_si_drv …, about 30 minutes boot is completed.

First try setting IPMI toSharedin BIOS, if the option is available. When booting your installation media, pressShiftOto display the boot arguments and addnoipmiEnabledto the boot arguments. Remember to do the same once the
installation/upgrade is complete. Manually turn off or remove the module
by turning the optionVMkernel.Boot.ipmiEnabledoff in vSphere or using the commands below:

# Do a dry run first:
esxcli software vib remove –dry-run –vibname ipmi-ipmi-si-drv
# Remove the module:
esxcli software vib remove –vibname ipmi-ipmi-si-drv

or try the following command in an unsupported shell connection:

esxcfg-module -d ipmi_si_drv

This disables the module although it still gets loaded.

Use a-largument to see what modules are enabled/loaded
and check that your desired one is disabled. This appears to be
persistent across a reboot.