Updateing iDRAC to 4.20.20.20

I would recommend to choose one FW from each year based on release date and perform staged update. You can go to Version section on support site for iDRAC and BIOS to get release date and link for old releases.

Below could be on upgrade path you can follow

iDRAC 4.00.00.00

BIOS 2.10.2

iDRAC 5.00.00.00

BIOS 2.15.1

iDRAC 6.00.02.00

Thanks for the answer. How long do these updates regularly take?

Edit: Oh yeah, one more thing. Since the 2.4.8 BIOS version is still from 2019, should we install one more version from 2020 before upgrading to 2.10.2 from 2021?

Update time varies server to server. BIOS update need a reboot of the server. iDRAC update does not need a reboot of the server and only iDRAC get rebooted. 

You can include one more BIOS version in your update.

How are you updating iDRAC? Are you using operating system to run Dell Update Package or are you using iDRAC itself. If you are using Operating system can you reboot the server and check the behavior.

We tried to use the iDRAC interface. On that note, how/where would we simply restart iDRAC? I found buttons for cold start and reset - does reset simply mean restart? Because then the german translation is a bit wonky with "Zurücksetzen" which is normally used to completely reset a system and not just restart it.

Edit:

We now tried a soft reset as well as clearing the job queue. We still get the same error as before.

Sadly, the iDRAC Update didn't work. We first updated the BIOS from 2.4.8 to version 2.8.2 and that worked without a problem. However, when we tried to update iDRAC we got an error when the restart should happen, as that didn't occur:

We tried it three times: First with a manual power off and then power on, but that didn't change the firmware to 4.00.00.00. After the second try, since the error simply states to try it again, we did exactly that, but it still didn't change anything. The last thing we did was to simply upgrade to the next version, which would be 3.30.30.30. However, we still got the same error message, that an error occured during restart.

Any suggestions what else we could try?

You can refer below link with different methods on resetting iDRAC

https://www.dell.com/support/kbdoc/en-us/000126703/how-to-reset-the-internal-dell-remote-access-controller-idrac-on-a-poweredge-server 

Okay, I already tried the reset/reboot via web GUI and that worked. But trying to install the firmware update still didn't work, I still got the error when it tried to reboot after installing.

Our OS is a Linux. Do we need RACADM to update the iDRAC firmware directly on Linux?