Preparation for Recitation on ZFS
Read The Zettabyte File System. It was published in the Usenix Symposium on File and Storage Technologies in 2003. This is your third file system; you have now read about the Unix Filesystem, GFS, and now ZFS.
The Introduction of the paper highlights the goals of the system and Section 2 discusses what the authors identify as their design principles. Section 3 describes their design, both the supporting elements and their approach to providing the POSIX layer. POSIX is the "Portable Operating System Interface" standardized by the IEEE for providing compatibility with various versions of Unix. Section 4 considers several use scenarios, although Section 5, in discussing design tradeoffs identities several key issues that are not considered in Section 4.The paper concludes with several brief sections on related work, future work, the current status and conclusions.
As you read the paper, consider the following questions:
- In terms of the design principles we have discussed in 6.033, which ones did the authors apply?
- How did they apply them?
- In light of the End-to-end arguments and the content of lectures on reliability and transactions, think about where the authors chose to provide those capabilities.
Question for Recitation
Before you come to this recitation, write up (on paper) a brief answer to the following (really—we don't need more than a couple sentences for each question). If your TA has requested that you email your answer to them, you may do that instead, but it should still be handed in before your recitation begins.
Your answers to these questions should be in your own words, not direct quotations from the paper.
- What aspect(s) of the Unix file system was ZFS designed to overcome?
- How is ZFS designed to overcome those issues?
- Why is it important for ZFS to overcome those aspects? Why is GFS not an adequate solution?