I am planning to upgrade my 6500 ios to s72033-adventerprisek9_wan-mz.122-33.SXI13, which need 512 mb of flash. But I have only 256 mb flash with me. Is there any way to upgrade the ios without flash card.
Even if you could make it work (delete current image, squeeze bootflash, etc.) I wouldn't recommend trying it. For about $US100 you can get a 512 MB compact flash card that will give you enough memory. that's a small investment for a core switch upgrade.