What is Boot Media device ?

[Ontapforrum]

I think as far Data Ontap 8 onwards is concerned :The OS (ontap operation system) is stored on the CF/USB flash boot_media device in the controller (depending upon the Model). The root aggregate contains the root volume that stores OS related stuff like configuration and logs. However it boots from boot_media device. Thanks!

[CHRISMAKI]

Not just v8+, I've had to do 3am change windows replacing the CF media gone bad in 7-mode gear...can't remember the exact model, ugly beige bezel with DS14's attached.

[Sebastian_Goetze]

Just to mention: the whole of ONTAP itself is not stored on the boot medium, but on vol0 in the root aggregate.

But it is started from the pre-boot-environment that's stored on the Boot Medium. I.e. there's kernel(s) and drivers and stuff, but all of ONTAP, let alone 2 versions ("images") of it, don't fit on it.

[Sebastian_Goetze]

Essentially it's what is read and started to get you to the Pre-Boot-Environment ("Loader"), from which you can start ONTAP, get into maintenance mode and so on.

As others mentioned, nowadays it's a internal "USB"-flash-device.

Previously it used to be a CF-card.

Before that it was a floppy disk.  (Kernels used to be small back then, also...)   🙂

[Shoniqua4]

I'm new to storage systems hardware in general and really appreciate the information shared here!  Coming from a purely software background,  I'm trying to understand the hardware/software interplay involved in storage systems. 

Regarding NetApp -- say you have a healthy FAS 2650 system running OnTAP 9.7.  By "healthy", I mean it will allow you to do a "Normal Boot". 
Then you get what someone tells you is a FAS 2750 controller that does not have a boot card in it.  The same someone tells you there is an old FAS 2750 chassis laying around with some existing internal drives but who knows what version of OnTap that system was using before the controllers in it were removed.

Can you take the boot card from a controller in your healthy FAS 2650 system,  put the boot card into the FAS 2750 controller, insert the FAS 2750 controller in the FAS 2750 chassis and get it to "work" -- ie, allow a "Normal Boot"?