Assuming you have dual SUP in your chassis and I will assume you know what is the different between SP (switch processor) and RP (route processor).SP is a.k.a. SUP, where RP is a.k.a. MSFC.

On the active SUP:

disk0: - the CF card slot in the SUP

bootflash: - flash memory on the RP

sup-bootdisk: or sup-bootflash: (depend on the version) - flash memory on the SP

For Standby SUP, add the slave keyword in front of the above memory space. Like slavedisk0: is the CF card slot on the standby SUP.

HTH,

jerry