Yes, it is safe.  It can be run from within the OS, or you can boot to SBUU and use SUU as the repository for the update packages. In most cases, it is easier to update from Windows, but it is not necessary. When/if getting update files from support.dell.com, use the Update Packages for Microsoft Windows format.
Hi, I have PowerEdge 2900 server. Current configuration I see on OMSA: BIOS version 2.3.1 (old) Controller PERC 6/i Integrated.Firmware version is out of date. Firmware Version 6.0.2-0002 Minimum Required Firmware Version 6.3.0-0001 Driver Version 4.05.01.64 Storport Driver Version 6.1.7601.17577   I need to upgrade Controller firmware and do Windows updates on this server. My questions: Is this the correct order to do upgrade:
PowerEdge 2900 Controller firmware and drivers upgrade