I've seen a lot of posts regarding the way in which a 6500 finds its boot image. None of them have answered my question, so here goes:
I have a 6504E running Native IOS that I use in a lab environment. I'm running the image s72033-ipservices_wan-mz.122-33.SXI2.bin, and it's too big to fit on the 64 MB of flash in my 720 supervisor (image is 96+ MB). So I can't copy the disk0 image to sup-bootflash. When I have a config loaded, I specify the 'boot system disk0:s72033-ipservices_wan-mz.122-33.SXI2.bin' command and all is well. However, since this is in a lab environment, I often clear the startup config and reload it. Every time I do that, the system loses that boot system command and I have to type the boot command followed by the image location from rommon. This is getting tiresome, especially when I think there's probably a way to avoid this. None of the documents I have read tell me how this can be solved. So in short, image is too large to fit into sup-bootflash and the switch doesn't have a boot system command to read. I also tried set commands (i.e. BOOT=disk0:s72033-ipservices_wan-mz.122-33.SXI2.bin) and then just typed 'boot' and it couldn't find an image.