Resetting root password in vCenter Server Appliance 6.5 – 7.x
Reboot the vCenter Server Appliance.
After the VCSA Photon OS starts, press the e key to enter the GNU GRUB Edit Menu.
Locate the line that begins with the word Linux.
Append these entries to the end of the line:
Press F10 to continue booting.
Run the command
mount -o remount,rw /
In the Command prompt, enter the command passwd and provide a new root password (twice for confirmation):
Unmount the filesystem by running this command (yes, the unmount command is umount – it’s not a spelling error):
Reboot the vCenter Server Appliance by running this command: