Here are his reasons for generally avoiding ZFS from what I consider most important to least.
- The kernel team may break it at any time, and won't care if they do.
- It doesn't seem to be well-maintained.
- Performance is not that great compared to the alternatives.
- Using it opens you up to the threat of lawsuits from Oracle. Given history, this is a real threat. (This is one that should be high for Linus but not for me - there is no conceivable reason that Oracle would want to threaten me with a lawsuit.)
- The kernel team may break it at any time, and won't care if they do.
- It doesn't seem to be well-maintained.
- Performance is not that great compared to the alternatives.
- Using it opens you up to the threat of lawsuits from Oracle. Given history, this is a real threat. (This is one that should be high for Linus but not for me - there is no conceivable reason that Oracle would want to threaten me with a lawsuit.)