Just thought I’d post this little nugget of information; in case some other pool soul is having a similar problem. I’ve recently been upgrading two VxRail clusters to the latest code and suffered the same problem in both clusters. The code update was to the latest, 4.7.211 and some hosts in the cluster were repeatedly failing to upgrade their firmware. The host ESXi software was upgrading without any problems, some were just failing on firmware.
After a lot of head scratching and a call to Dell support a reset to the iDRAC was advised. I assumed that’ll never work, it’s only out of band management, why would that fix a firmware update problem? Well it appears that the iDRAC reset can, on occasion, fix this sort of problem, as after the first cluster upgrade was complete and I came to the second cluster I ran into the same problem. Lo and behold, I tried the same trick without Dell support this time, and to my surprise, it worked.
I guess the iDRAC is more intimately involved in the firmware upgrade process than I assumed. So, keep this in mind for problems of this sort, I know I will.