The vFlash is meant for a single time boot, not for a regular boot device. You'll want to use something else for a regular boot device. One option is to put a USB memory key in the USB port on the 2nd riser (see page 62 of the online hardware owner's manual).
Hi there,I've got: Dell PE R420 Server SD card formated and initialized = vflash  When I'm shutting down server and booting up it again, it won't boot because can't get a boot media, it's trying to scan hdd, floppy, dvd,network but don't even try vflash. To boot from vflash (i've got esxi5.1 server on it), I must do this: open web idrac7 and login in to it. Select vflash, attach media, check the checkbox in 'attach' - reboot my server.  Think it's not right, mb there's a better way how can I automate booting my server from vflash drive?
R420 vflash boot