RE: HMC upgrade: Stuck at "localhost login:"

Solution summary:

If you are stuck at "localhost login:" do not wait on it - you're FUBAR. Restore from snapshot. The upgrade only restored the base OS and not the HMC code.

If you put on upgrade fix MH01857, and then put on any other fixes, this is what caused the upgrade to fail.
After you restored from snapshot you do not have to remove any fixes. Just run one of the following again depending on whether your HMC goes to the internet directly
updhmc -t ftp -h public.dhe.ibm.com -u anonymous --passwd anonymous -r -f /software/server/hmc/fixes/MH01857_x86.iso
updhmc -t ftp -h yourlocalftpserver -u yourusername --passwd yourpassword -r -f /home/ROB/HMC/vHMC_V9/MH01857/vMH01857_x86.iso
replacing /home/ROB/HMC/vHMC_V9/MH01857/vMH01857_x86.iso with whatever the file path is on your ftp server. This was where I stuck it on my IBM i.

Once you've done this then start the big upgrade again following it's steps carefully.

Rob Berendt