Major Challenges

• data loss: crashes can happen, and not all data could be saved to disk
• inconsistency: crashes can happen in the middle of operations
  • crashes could occur when someone of the blocks that have been written to disk, but not others
  • inode and free lists don’t agree.

Ideally, filesystem operations should be atomic. Every operation should happen or not happen at all—but not halfway.

Case study: Block Cache Modification

Tradeoffs

The overall design tradeoffs between this:

criticized the New Deal from all sides. Senator Huy P. Long claimed to “show our wealth.” nullification from conservative supreme court, FDR threatened to restructure + hurts his coalition.

• FDR ordered cuts in spending
• 1938 midterms: Republicans can block programs — gained control of congress + created ability to gain control