If you have an 11th generation Dell PowerEdge R810 , PowerEdge R910 server, or a PowerEdge M910 blade server, there is a pretty recent (April 9, 2012) Urgent update to version 2.7.0 for the main system BIOS. Here is Dell’s description of the update:
Dell highly recommends applying this update as soon as possible. The update contains changes to improve the reliability and availability of your Dell system.
This BIOS release resolves the potential for unpredictable system behavior in Dell systems running Intel(R) Xeon(R) Processor E7-2800/4800/8800 Series. For systems running Intel(R) Xeon(R) Processor E7-2800/4800/8800 Series, Dell strongly recommends applying this critical update as soon as possible. Systems updated with this version of BIOS or newer and running Intel(R) Xeon(R) Processor E7-2800/4800/8800 Series will be blocked from flashing to BIOS versions earlier than 2.7.0.
Update on April 19: I forgot about the M910, which I have added to the post.
You can use Dell OMSA, msinfo32.exe, or CPU-Z to discover the version of your main system BIOS. For example, Figure 1 shows the BIOS Version/Date of the little desktop system I am writing this on. Figure 2 shows the Mainboard tab of CPU-Z.
Figure 1: msinfo32.exe Output
Figure 2: CPU-Z Mainboard tab
If you discover that you are on an older version, I think you should strongly consider scheduling a maintenance window so that you can get this new version installed on your servers. Updating your main system BIOS will require a reboot of the system. If you have an HA solution in place, such as failover clustering, database mirroring, or SQL Server 2012 AlwaysOn Availability Groups, you can do a rolling upgrade to minimize your downtime.