Lecture 11

File Systems

Apple File System (APFS) is the new system built by Apple for macOS devices

HFS+ was the system built by Apple for macOS devices

NTFS: "New Technology File System"

• Has been used by Windows since 1993

• They released a newer one, Resilient File System (ReFS) is the newer version, is used on Windows Server but hasn't been ready to introduce to the masses any time sooner than "some day" since 2012

In the future, I'd like to take more notes on this article that taught me about diagnosing and treating time machine problems in terminal.

sudo defaults write /System/Library/Launch Daemons/com.apple.backupd-auto StartInterval -int 1800

If you try to overflow a buffer inside a segment, that can succeed.

If you try to overflow a buffer on the boundary of a segment, that will fail, because hardware checks the boundaries. Every process has a segment table, which has every entry for one segment, the beginning, the length, and the hardware uses this to check the boundaries.

If the next page is not in physical memory, but instead, is located on disk, there will be a page fault, and it will be brought back. But, if the next page is there, then there will be no page fault, and the buffer overrun will succeed.

Question 1

• Did you find my graphics to be useful teaching tools during lecture?

  Answer: Yes

Question 2

Question 8

• What would you like to go over more next time?

  Answer: Can we talk more about reference monitors in the next lecture, in particular, what are some common cybersecurity alternatives that have arisen as the industry has continued to neglect reference monitors, and what are the pros/cons/tradeoffs of such alternatives?